Industry and research experience in water resources, hydraulics, floodplain management, water quality and pollution transport processes.
Can supervise: YES
Hydraulics; and water quality
48362 - Hydraulics4917 - Urban Stormwater Design49117 - Floodplain management
McLuckie, D & Sayers, P 2018, Strategic Management of Flood Risk.
This book covers an extensive range of issues related to constructed wetlands for treatment of stormwater and wastewater. Chapter One covers the functions and classifications of constructed wetlands, treatment processes of wetlands and a detailed description of microphytes. Chapter Two provides details of the design of wetlands and their construction. Chapter Three provides details of the important issue of operation and maintenance of constructed wetlands. Chapter Four highlights all the experience gained from managing a large and prominent urban wetland. Chapter Five outlines the importance of engaging the community when planning, designing and constructing wetlands. The book is useful for environmental professionals desiring a good appreciation of the concepts in constructed wetlands. This book is also a useful reference for graduate and post-graduate students of civil and environmental engineering, chemical engineering, environmental management or environmental science. © 2008 by Nova Science Publishers, Inc. All rights reserved.
Lyu, H, Dong, Z, Roobavannan, M, Kandasamy, J & Pande, S 2019, 'Rural unemployment pushes migrants to urban areas in Jiangsu Province, China', Palgrave Communications, vol. 5, no. 1.View/Download from: UTS OPUS or Publisher's site
© 2019, The Author(s). Migration is often seen as an adaptive human response to adverse socio-environmental conditions, such as water scarcity. A rigorous assessment of the causes of migration, however, requires reliable information on the migration in question and related variables, such as, unemployment, which is often missing. This study explores the causes of one such type of migration, from rural to urban areas, in the Jiangsu province of China. A migration model is developed to fill a gap in the understanding of how rural to urban migration responds to variations in inputs to agricultural production including water availability and labor and how rural population forms expectations of better livelihood in urban areas. Rural to urban migration is estimated at provincial scale for period 1985–2013 and is found to be significantly linked with rural unemployment. Further, migration reacts to a change in rural unemployment after 2–4 years with 1% increase in rural unemployment, on average, leading to migration of 16,000 additional people. This implies that rural population takes a couple of years to internalize a shock in employment opportunities before migrating to cities. The analysis finds neither any evidence of migrants being pulled by better income prospects to urban areas nor being pushed out of rural areas by water scarcity. Corroborated by rural–urban migration in China migration survey data for 2008 and 2009, this means that local governments have 2–4 years of lead time after an unemployment shock, not necessarily linked to water scarcity, in rural areas to prepare for the migration wave in urban areas. This original analysis of migration over a 30-year period and finding its clear link with unemployment, and not with better income in urban areas or poor rainfall, thus provides conclusive evidence in support of policy interventions that focus on generating employment opportunities in rural areas to reduce migration flow to urban areas.
Tri, DQ, Kandasamy, J & Don, NC 2019, 'Quantitative assessment of the environmental impacts of dredging and dumping activities at sea', Applied Sciences (Switzerland), vol. 9, no. 8.View/Download from: UTS OPUS or Publisher's site
© 2019 by the authors. The dumping of dredge materials often raises concerns about the release of pollutants to the marine environment. Wind data from the Global Forecast System (GFS) model was used to simulate the wind-wave propagation from offshore in a two-dimensional (2D) model during September and October 2016. The calibration and validation of the 2D model showed a high conformity in both the phases and amplitude between the observed and simulated data. The 2D mud transport simulation results of three scenarios showed that the concentration of suspended material in the third scenario tested (scenario 3) was greater than 0.004 kg/m3 in the low tide, spreading to a 9 km2 area, and in the high tide, the concentration was 0.004 kg/m3 in a 6 km2 area. Finally, the results of 2D particle tracking (PT) showed changes in the seabed due to the concentration of dredged material, and its dump (approximately 180 days) increased from 0.08 m to 0.16 m in 2.85 ha. In scenario 3, the element block moved quite far-approximately 2.9 km-from the dredge position. Therefore, the simulation results were qualified, as the dredging position situated far from the sea is significantly affected by the direction and velocity of wave-wind in the dredging position.
Tri, DQ, Mai Linh, NT, Thai, TH & Kandasamy, J 2019, 'Application of 1D–2D coupled modeling in water quality assessment: A case study in Ca Mau Peninsula, Vietnam', Physics and Chemistry of the Earth, vol. 113, pp. 83-99.View/Download from: UTS OPUS or Publisher's site
© 2018 Elsevier Ltd A few 1D and 2D models are used to simulate and calculate the water level and water quality regarding four state variable (DO, NH4, NO3, and BOD) observations in the main rivers and coastal estuaries on the Ca Mau peninsula. This study calibrates and validates 1D and 2D models during the dry and flood seasons for 2014 and 2015, as well as assesses water quality in coastal estuaries during the dry and flood season of 2016 by using a 2D model. The calibration and validation results of the hydrodynamic 1D and 2D models show that there is a high degree of conformity regarding the phase and amplitude of water level at observing stations with mean absolute error (MAE) ranges from 0.05 m to 0.37 m. The RMSE–observation standard deviation ratio (RSR) vary from 0.12 to 0.64, and the percent bias (PBIAS) is from −8.9% to 3.2%. Calibration and validation of water quality parameter (DO, NH4, NO3, and BOD5 concentration) results have a high correlation coefficient during both the dry and flood season of 2014 and 2015. The standards, originating from the National Technical Regulation on Surface Water quality and on Coastal Water Quality, are used to evaluate pollutant concentrations in estuaries in the study area during the dry and flood seasons of 2016. The water quality parameters contain DO (4.6 mg/l–7.9 mg/l) and BOD (4.6 mg/l–10.7 mg/l) concentrations over the National Technical Regulation on Surface and Coastal Water Quality and the A1 limit with DO (>4 mg/l) and BOD5 (4 mg/l) on surface water quality for domestic water use in the dry and flood seasons. The calculated results will help managers make better plans for aquaculture and aquatic conservation zones in coastal estuaries in the future.
Areerachakul, N, Sakulkhaemaruethai, S, Johir, MAH, Kandasamy, J & Vigneswaran, S 2019, 'Photocatalytic degradation of organic pollutants from wastewater using aluminium doped titanium dioxide', Journal of Water Process Engineering, vol. 27, pp. 177-184.View/Download from: UTS OPUS or Publisher's site
© 2018 Elsevier Ltd The objective of this research was to study the performance of batch and continuous recirculating reactor to photo-degrade dye and synthetic wastewater. Here, Aluminium (Al) was used as the doped metal. The commercially available TiO2 P-25 and Al (NO3)3 was used as a Ti-precursor and doping agent, respectively, via the impregnation method. Various parameters such as the concentration of the doping agent, and calcination temperature were studied. The TiO2 nanocrystal doped with Al was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and thermogravimetric analyzer (TGA). The photocatalytic performance of Al-doped nanoparticle was quantified by the degradation of methylene blue (MB) solution under a visible light irradiation condition. Its performance was compared against undoped-nano-TiO2. The results showed that Al(NO3)3 solution with a concentration of 0.25% and volume of 100 cm/ml, and calcined at 300 ๐C for 4 h, was the optimum condition of Al-doped nano-TiO2. Furthermore, the highest pseudo-first-order kinetic rate was 0.096 where the doped Al(NO3)3 of 0.75 w/v was used in the batch reactor. The Al-doped nano-TiO2 that was obtained has the potential for use as a photocatalyst for degradation organics pollutant from wastewater under the visible light irradiation. The highest removal of organic pollutants from synthetic wastewater was 75% using TiO2 P-25 alone at 2 g/L dosage. In addition, the removal of organic pollutant by TiO2/doped with Al was 80% at a dosage of 0.5 g/L and was 85% at a dosage of 1 g/L.
Bui, HH, Ha, NH, Nguyen, TND, Nguyen, AT, Pham, TTH, Kandasamy, J & Tien, VN 2019, 'Integration of SWAT and QUAL2K for water quality modeling in a data scarce basin of Cau River basin in Vietnam', ECOHYDROLOGY & HYDROBIOLOGY, vol. 19, no. 2, pp. 210-223.View/Download from: UTS OPUS or Publisher's site
Jo, Y, Johir, MAH, Cho, Y, Naidu, G, Rice, SA, McDougald, D, Kandasamy, J, Vigneswaran, S & Sun, S 2019, 'A comparative study on nitric oxide and hypochlorite as a membrane cleaning agent to minimise biofilm growth in a membrane bioreactor (MBR) process', Biochemical Engineering Journal, vol. 148, pp. 9-15.View/Download from: UTS OPUS or Publisher's site
© 2019 Elsevier B.V. Reverse osmosis concentrates (ROC) produced from water reclamation plants can threaten the environment if it is not appropriately treated before discharge. A membrane bioreactor (MBR) process to treat ROC was used in this project. In an MBR, fouling is an essential and inevitable phenomenon which leads to higher operational and capital costs. A comparative study on chemical cleaning, such as sodium hypochlorite (NaOCl) and nitric oxide (NO), was experimentally evaluated together with the influence of filtration flux. Exposure to a low concentration of NO reduced biofilms in an MBR system. NO treatment delayed the formation of new biofilm biomass on the membrane. NO also showed good performance in reducing membrane fouling and had no adverse effect on activated sludge and the environment. In MBR, the bacterial community was dominated by Proteobacteria (61%), with Alpha and Beta-proteobacteria representing approximately 54% of the community. After NO treatment, the relative abundance of the Proteobacteria decreased to 44%, and this was also reflected in a reduction in Alpha and Beta-proteobacteria, to 30% and 5% respectively. Thus, NO treatment resulted in the decrease of the relative biofilms associated with reduced MBR performance.
Ekanayake, D, Aryal, R, Johir, MAH, Loganathan, P, Bush, C, Kandasamy, J & Vigneswaran, S 2019, 'Interrelationship among the pollutants in stormwater in an urban catchment and first flush identification using UV spectroscopy', CHEMOSPHERE, vol. 233, pp. 245-251.View/Download from: UTS OPUS or Publisher's site
Jamil, S, Loganathan, P, Kandasamy, J, Listowski, A, Khourshed, C, Naidu, R & Vigneswaran, S 2019, 'Removal of dissolved organic matter fractions from reverse osmosis concentrate: Comparing granular activated carbon and ion exchange resin adsorbents', JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING, vol. 7, no. 3.View/Download from: UTS OPUS or Publisher's site
Jamil, S, Loganathan, P, Listowski, A, Kandasamy, J, Khourshed, C & Vigneswaran, S 2019, 'Simultaneous removal of natural organic matter and micro-organic pollutants from reverse osmosis concentrate using granular activated carbon', WATER RESEARCH, vol. 155, pp. 106-114.View/Download from: UTS OPUS or Publisher's site
Atiquzzaman, M & Kandasamy, J 2018, 'Robustness of Extreme Learning Machine in the prediction of hydrological flow series', COMPUTERS & GEOSCIENCES, vol. 120, pp. 105-114.View/Download from: UTS OPUS or Publisher's site
Jonasson, OJ & Kandasamy, J 2018, 'Decentralised water reuse in Sydney, Australia: Drivers for implementation and energy consumption', Journal of Environmental Engineering and Science, vol. 13, no. 1, pp. 2-7.View/Download from: UTS OPUS or Publisher's site
© 2018 ICE Publishing all right reserved. Water recycling and reuse is becoming increasingly common throughout the world. The objective of this study was to compare five decentralised water recycling and reuse systems in Sydney, Australia, in terms of the drivers for their implementation and their ongoing energy consumption, allowing comparison to conventional water sources. The security of supply was found to be the main driver for four out of the five schemes. For the fifth scheme, the driver was to obtain a high environmental rating for the building it is located in. The analysis shows that water reuse can provide water at the same or less energy consumption compared to water supplied through the mains network. However, where the water recycling ethos of ‘fit for purpose’ is not considered, this can often lead to a significant overall increase in power consumption. This study highlights the need for regulatory bodies to consider a wider range of impacts when preparing guidelines and incentive schemes for water reuse. When the focus is too narrow, there is a risk that unintentional negative impacts such as increased power consumption and potential carbon dioxide emissions are the outcomes.
Roobavannan, M, Van Emmerik, THM, Elshafei, Y, Kandasamy, J, Sanderson, MR, Vigneswaran, S, Pande, S & Sivapalan, M 2018, 'Norms and values in sociohydrological models', Hydrology and Earth System Sciences, vol. 22, no. 2, pp. 1337-1349.View/Download from: UTS OPUS or Publisher's site
© Author(s) 2018. Sustainable water resources management relies on understanding how societies and water systems coevolve. Many place-based sociohydrology (SH) modeling studies use proxies, such as environmental degradation, to capture key elements of the social component of system dynamics. Parameters of assumed relationships between environmental degradation and the human response to it are usually obtained through calibration. Since these relationships are not yet underpinned by social-science theories, confidence in the predictive power of such place-based sociohydrologic models remains low. The generalizability of SH models therefore requires major advances in incorporating more realistic relationships, underpinned by appropriate hydrological and social-science data and theories. The latter is a critical input, since human culture - especially values and norms arising from it - influences behavior and the consequences of behaviors. This paper reviews a key social-science theory that links cultural factors to environmental decision-making, assesses how to better incorporate social-science insights to enhance SH models, and raises important questions to be addressed in moving forward. This is done in the context of recent progress in sociohydrological studies and the gaps that remain to be filled. The paper concludes with a discussion of challenges and opportunities in terms of generalization of SH models and the use of available data to allow future prediction and model transfer to ungauged basins.
Nur, T, Loganathan, P, Ahmed, MB, Johir, M, Kandasamy, J & Vigneswaran, S 2018, 'Struvite production using membrane-bioreactor wastewater effluent and seawater', Desalination, vol. 444, pp. 1-5.View/Download from: UTS OPUS or Publisher's site
© 2018 Elsevier B.V. Wastewater phosphorus (P) released into natural water bodies such as lakes and rivers, can cause water pollution as a result of eutrophication. If this P is effectively removed from wastewaters and economically recovered for use as fertilisers, not only can the water pollution be controlled, but also reduce the anticipated global shortage of P. This scarcity will result from the natural phosphate rock reserve being exhausted. Three experiments were conducted using membrane-bioreactor effluent (MBR, 35 mg PO 4 /L) and reverse osmosis concentrate (ROC, 10 mg PO 4 /L) waters to supply phosphate, and sea water (1530 mg Mg/L) to supply Mg for the production of struvite. The phosphate in the MBR and ROC was concentrated approximately 15 times by adsorption onto an ion exchange resin column followed by desorption. Struvite was precipitated by mixing the desorbed solution with seawater and NH 4 Cl. The chemical composition and mineral structure of the precipitates agreed with those of the reference struvite. When Ca in seawater (300 mg Ca/L) was removed before mixing the water with MBR or ROC, the purity of the struvite improved.
Nur, T, Loganathan, P, Johir, MAH, Kandasamy, J & Vigneswaran, S 2018, 'Removing rubidium using potassium cobalt hexacyanoferrate in the membrane adsorption hybrid system', Separation and Purification Technology, vol. 191, pp. 286-294.View/Download from: UTS OPUS or Publisher's site
© 2017 Elsevier B.V. Highly-priced rubidium (Rb) can be effectively extracted from seawater using potassium cobalt hexacyanoferrate (KCoFC) and ammonium molybdophosphate (AMP) adsorbents in the membrane adsorption hybrid system (MAHS). KCoFC ( < 0.075 mm), KCoFC (0.075–0.15 mm), and AMP ( < 0.075 mm) had Langmuir adsorption capacities of 145, 113, and 77 mg/g at pH 6.5–7.5, respectively. When KCoFC ( < 0.075 mm) at a dose of 0.2 g/L was initially added to 4 L of a solution containing 5 mg Rb/L in the MAHS and 25% of the initial dose was repeatedly added every hour, the amount of Rb removed remained steady at 90–96% for the experiment's 26 h duration. The removal of Rb by AMP under similar conditions was 80–82%. The cumulative Rb removed by KCoFC ( < 0.075 mm) in MAHS was only 33% reduced in the presence of high concentrations of other cations in synthetic seawater compared to that in solution containing only Rb. Approximately 30% of the adsorbed Rb was desorbed using 1 M KCl. When the desorbed solution was passed through a column containing resorcinol formaldehyde (RF), 35% of the Rb in the desorbed solution was adsorbed on RF. Furthermore 50% of the Rb adsorbed on RF was recovered by 1 M HCl leaching of the column. This sequence of concentration and separation of Rb in the presence of other cations in synthetic seawater is an efficient method for recovering pure Rb from real seawater and seawater reverse osmosis brine.
Eeshwarasinghe, D, Loganathan, P, Kalaruban, M, Sounthararajah, DP, Kandasamy, J & Vigneswaran, S 2018, 'Removing polycyclic aromatic hydrocarbons from water using granular activated carbon: kinetic and equilibrium adsorption studies', Environmental Science and Pollution Research, vol. 25, no. 14, pp. 13511-13524.View/Download from: UTS OPUS or Publisher's site
© 2018, Springer-Verlag GmbH Germany, part of Springer Nature. Polycyclic aromatic hydrocarbons (PAHs) constitute a group of highly persistent, toxic and widespread environmental micropollutants that are increasingly found in water. A study was conducted in removing five PAHs, specifically naphthalene, acenaphthylene, acenaphthene, fluorene and phenanthrene, from water by adsorption onto granular activated carbon (GAC). The pseudo-first-order (PFO) model satisfactorily described the kinetics of adsorption of the PAHs. The Weber and Morris diffusion model’s fit to the data showed that there were faster and slower rates of intra-particle diffusion probably into the mesopores and micropores of the GAC, respectively. These rates were negatively related to the molar volumes of the PAHs. Batch equilibrium adsorption data fitted well to the Langmuir, Freundlich and Dubinin–Radushkevich models, of which the Freundlich model exhibited the best fit. The adsorption affinities were related to the hydrophobicity of the PAHs as determined by the log Kow values. Free energies of adsorption calculated from the Dubinin–Radushkevich model and the satisfactory kinetic data fitting to the PFO model suggested physical adsorption of the PAHs. Adsorption of naphthalene, acenaphthylene and acenaphthene in fixed-bed columns containing a mixture of GAC (0.5 g) + sand (24.5 g) was satisfactorily simulated by the Thomas model.
Kalaruban, M, Loganathan, P, Kandasamy, J & Vigneswaran, S 2018, 'Submerged membrane adsorption hybrid system using four adsorbents to remove nitrate from water.', Environmental Science and Pollution Research, vol. 25, no. 21.View/Download from: UTS OPUS or Publisher's site
Nitrate contamination of ground and surface waters causes environmental pollution and human health problems in many parts of the world. This study tests the nitrate removal efficiencies of two ion exchange resins (Dowex 21K XLT and iron-modified Dowex 21K XLT (Dowex-Fe)) and two chemically modified bio-adsorbents (amine-grafted corn cob (AG corn cob) and amine-grafted coconut copra (AG coconut copra)) using a dynamic adsorption treatment system. A submerged membrane (microfiltration) adsorption hybrid system (SMAHS) was used for the continuous removal of nitrate with a minimal amount of adsorbents. The efficiency of membrane filtration flux and replacement rate of adsorbent were studied to determine suitable operating conditions to maintain the effluent nitrate concentration below the WHO drinking standard limit of 11.3 mg N/L. The volume of water treated and the amount of nitrate adsorbed per gramme of adsorbent for all four flux tested were in the order Dowex-Fe > Dowex > AG coconut copra > AG corn cob. The volumes of water treated (L/g adsorbent) were 0.91 and 1.85, and the amount of nitrate removed (mg N/g adsorbent) were 9.8 and 22.2 for AG corn cob and Dowex-Fe, respectively, at a flux of 15 L/(m2/h).
Kalaruban, M, Loganathan, P, Shim, WG, Kandasamy, J & Vigneswaran, S 2018, 'Mathematical modelling of nitrate removal from water using a submerged membrane adsorption hybrid system with four adsorbents', Applied Sciences (Switzerland), vol. 8, no. 2.View/Download from: UTS OPUS or Publisher's site
© 2018 by the authors. Excessive concentrations of nitrate in ground water are known to cause human health hazards. A submerged membrane adsorption hybrid system that includes a microfilter membrane and four different adsorbents (Dowex 21K XLT ion exchange resin (Dowex), Fe-coated Dowex, amine-grafted (AG) corn cob and AG coconut copra) operated at four different fluxes was used to continuously remove nitrate. The experimental data obtained in this study was simulated mathematically with a homogeneous surface diffusion model that incorporated membrane packing density and membrane correlation coefficient, and applied the concept of continuous flow stirred tank reactor. The model fit with experimental data was good. The surface diffusion coefficient was constant for all adsorbents and for all fluxes. The mass transfer coefficient increased with flux for all adsorbents and generally increased with the adsorption capacity of the adsorbents.
Nguyen, TC, Loganathan, P, Nguyen, TV, Kandasamy, J, Naidu, R & Vigneswaran, S 2018, 'Adsorptive removal of five heavy metals from water using blast furnace slag and fly ash.', Environmental science and pollution research international, vol. 25, no. 21, pp. 20430-20438.View/Download from: UTS OPUS or Publisher's site
Heavy metals can be serious pollutants of natural water bodies causing health risks to humans and aquatic organisms. The purpose of this study was to investigate the removal of five heavy metals from water by adsorption onto an iron industry blast furnace slag waste (point of zero charge (PZC) pH 6.0; main constituents, Ca and Fe) and a coal industry fly ash waste (PZC 3.0; main constituents, Si and Al). Batch study revealed that rising pH increased the adsorption of all metals with an abrupt increase at pH 4.0-7.0. The Langmuir adsorption maximum for fly ash at pH 6.5 was 3.4-5.1 mg/g with the adsorption capacity for the metals being in the order Pb > Cu > Cd, Zn, Cr. The corresponding values for furnace slag were 4.3 to 5.2 mg/g, and the order of adsorption capacities was Pb, Cu, Cd > Cr > Zn. Fixed-bed column study on furnace slag/sand mixture (1:1 w/w) revealed that the adsorption capacities were generally less in the mixed metal system (1.1-2.1 mg/g) than in the single metal system (3.4-3.5 mg/g). The data for both systems fitted well to the Thomas model, with the adsorption capacity being the highest for Pb and Cu in the single metal system and Pb and Cd in the mixed metal system. Our study showed that fly ash and blast furnace slag are effective low-cost adsorbents for the simultaneous removal of Pb, Cu, Cd, Cr and Zn from water.
Aryal, R, Beecham, S, Sarkar, B, Chong, MN, Kinsela, A, Kandasamy, J & Vigneswaran, S 2017, 'Readily Wash-Off Road Dust and Associated Heavy Metals on Motorways', Water, Air, and Soil Pollution, vol. 228, no. 1, pp. 1-12.View/Download from: UTS OPUS or Publisher's site
© 2016, Springer International Publishing Switzerland. Road dust contains a wide range of potentially health-hazardous pollutant sources. In this study, road dust samples were collected from nine locations along the Sydney orbital motorway during wet weather events and analysed for their mineralogy and heavy metal contents. The aim of this study was to examine for the specific particle size fractions in road dust samples that can be associated with anthropogenic pollutant sources, mainly on the prevalence of heavy metals. Surface morphological and elemental composition of the road dust particles was analysed using scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM-EDX). The heavy metal contents and degree of contamination were also investigated including in the two specific particle size fractions of < 75 and 75–150 μm. It was found that the particle size fraction of < 75 μm made up between 6 and 16% of the entire particle size distributions and contributed to more than 90% of the heavy metal contents. In addition, a moderate to high degree of heavy metal contamination was measured in the collected road dust samples, and this was correlated well with the local traffic volumes. The good correlation between heavy metals and traffic volumes in the finer road dust particle size fraction of < 75 μm indicated that the finer road dust particles were not only important in terms of heavy metal attachment, accumulation and mobilisation during wet weather events but they could also provide evidence of potential anthropogenic pollution sources. These findings will facilitate our scientific understanding on the specific role and importance of particle size fractions on the mobilisation of pollutant sources, particularly heavy metals during wet weather events. It is anticipated that this study will assist in the development of best management practices for pollution prevention and control strategies on the frequency of road sweeping and rete...
Naidu, G, Jeong, S, Johir, MAH, Fane, AG, Kandasamy, J & Vigneswaran, S 2017, 'Rubidium extraction from seawater brine by an integrated membrane distillation-selective sorption system.', Water Research, vol. 123, pp. 321-331.View/Download from: UTS OPUS or Publisher's site
The ultimate goal of seawater reverse osmosis (SWRO) brine management is to achieve minimal liquid discharge while recovering valuable resources. The suitability of an integrated system of membrane distillation (MD) with sorption for the recovery of rubidium (Rb+) and simultaneous SWRO brine volume reduction has been evaluated for the first time. Polymer encapsulated potassium copper hexacyanoferrate (KCuFC(PAN)) sorbent exhibited a good selectivity for Rb+ sorption with 10-15% increment at 55 °C (Langmuir Qmax = 125.11 ± 0.20 mg/g) compared to at 25 °C (Langmuir Qmax = 108.71 ± 0.20 mg/g). The integrated MD-KCuFC(PAN) system with periodic membrane cleaning, enabled concentration of SWRO brine to a volume concentration factor (VCF) of 2.9 (65% water recovery). A stable MD permeate flux was achieved with good quality permeate (conductivity of 15-20 μS/cm). Repeated cycles of MD-KCuFC(PAN) sorption with SWRO brine enabled the extraction of 2.26 mg Rb+ from 12 L of brine (equivalent to 1.9 kg of Rb/day, or 0.7 tonne/yr from a plant producing 10,000 m3/day brine). KCuFC(PAN) showed a high regeneration and reuse capacity. NH4Cl air stripping followed by resorcinol formaldehyde (RF) resin filtration enabled to recover Rb+ from the desorbed solution.
Roobavannan, M, Kandasamy, J, Pande, S, Vigneswaran, S & Sivapalan, M 2017, 'Allocating Environmental Water and Impact on Basin Unemployment: Role of A Diversified Economy', Ecological Economics, vol. 136, pp. 178-188.View/Download from: UTS OPUS or Publisher's site
© 2017 Elsevier B.V. Water diversion for environmental pu rposes threatens many agricultural communities. This paper focuses on the water-agriculture-environment nexus in the Murrumbidgee River Basin, Australia, and attempts to explain how reduced water allocation to agriculture aimed at protecting the environment in turn impacted the wider economy and the community. Predictably reduced water allocation saw declines in agriculture production and employment. Despite this, paradoxically, the basin unemployment rate declined and basin median household income increased. To understand and interpret this, we first analyze available labour, economic and hydrology data, and then develop a simple dynamic model to interpret the observed pattern of basin employment and unemployment. Data analysis revealed the likely causes behind the paradox as (a) out-migration of people from the basin, and (b) absorption of the labour force in the fast growing non-agricultural sectors of the diversified basin economy. The model simulations reinforced this interpretation. Further model simulations under alternative realities of out-migration and sectoral transformation indicated that basins embedded in faster growing national economies, and are more diversified to begin with, are likely to be more conducive to agriculture sector reform (e.g., reduced water allocation) and environmental regeneration. This is a sobering message for other regions experiencing environmental degradation due to extensive agricultural development.
Roobavannan, M, Kandasamy, J, Pande, S, Vigneswaran, S & Sivapalan, M 2017, 'Role of Sectoral Transformation in the Evolution of Water Management Norms in Agricultural Catchments: A Sociohydrologic Modeling Analysis', Water Resources Research, vol. 53, no. 10, pp. 8344-8365.View/Download from: UTS OPUS or Publisher's site
© 2017. American Geophysical Union. All Rights Reserved. This study is focused on the water-agriculture-environment nexus as it played out in the Murrumbidgee River Basin, eastern Australia, and how coevolution of society and water management actually transpired. Over 100 years of agricultural development the Murrumbidgee Basin experienced a “pendulum swing” in terms of water allocation, initially exclusively for agriculture production changing over to reallocation back to the environment. In this paper, we hypothesize that in the competition for water between economic livelihood and environmental wellbeing, economic diversification was the key to swinging community sentiment in favor of environmental protection, and triggering policy action that resulted in more water allocation to the environment. To test this hypothesis, we developed a sociohydrology model to link the dynamics of the whole economy (both agriculture and industry composed of manufacturing and services) to the community's sensitivity toward the environment. Changing community sensitivity influenced how water was allocated and governed and how the agricultural sector grew relative to the industrial sector (composed of manufacturing and services sectors). In this way, we show that economic diversification played a key role in influencing the community's values and preferences with respect to the environment and economic growth. Without diversification, model simulations show that the community would not have been sufficiently sensitive and willing enough to act to restore the environment, highlighting the key role of sectoral transformation in achieving the goal of sustainable agricultural development.
Shrestha, A, Naidu, G, Johir, MAH, Kandasamy, J & Vigneswaran, S 2017, 'Performance of flocculation titanium salts for seawater reverse osmosis pretreatment', Desalination and Water Treatment, vol. 98, pp. 92-97.View/Download from: UTS OPUS or Publisher's site
© 2017 Desalination Publications. All rights reserved. This study evaluated the performance of titanium tetrachloride (TiCl4) and titanium sulphate (Ti(SO4)2) as coagulants to remove organic matter and solids from actual seawater. The coagulant performances were evaluated at different doses in terms of turbidity, dissolved organic carbon (DOC), humics (UV254), zeta potential and pH of the solution. The performance of Ti-salts were compared to ferric chloride (FeCl3), a commonly used coagulant. The results showed that at pH of 8.0 (closely similar to seawater pH), TiCl4showed relatively better performance over FeCl3and Ti(SO4)2for the same coagulant dose of 20 mg/L. TiCl4achieved a 70% DOC and UV254removal. This was approximately two times higher than achieved by FeCl3and Ti(SO4)2. Based on a floc zeta potential evaluation, the difference in performance of the coagulants were attributed to the coagulation mechanism. The coagulation mechanisms of Ti-salts were mainly charge neutralization while FeCl3was adsorption mechanism.
Nur, T, Loganathan, P, Kandasamy, J & Vigneswaran, S 2017, 'Removal of strontium from aqueous solutions and synthetic seawater using resorcinol formaldehyde polycondensate resin', Desalination, vol. 420, pp. 283-291.View/Download from: UTS OPUS or Publisher's site
© 2017 Elsevier B.V. Strontium (Sr) is a valuable metal found in abundance in seawater. However, its recovery from seawater has received little attention despite its many industrial applications. Batch and column adsorption experiments were conducted on the removal of Sr by resorcinol formaldehyde (RF) resin in the presence of co-existing cations at pH 7.5–8.5, where maximum adsorption was found. Batch adsorption capacities of cations followed the decreasing order of Sr > Ca > Mg > K, the order being the same as that of reduction of negative zeta potential. The adsorption data for Sr, Ca and Mg satisfactorily fitted to the Langmuir adsorption model with maximum adsorption capacities of 2.28, 1.25 and 1.15 meq/g, respectively. Selectivity coefficients for Sr with respect to other metals showed that Sr was selectively adsorbed on RF. Column adsorption data for Sr only solution fitted well to the Thomas model. Sr adsorption capacity in the presence of seawater concentrations of Ca, Mg, K and Na was reduced in both batch and column experiments with highest effect from Ca and Mg. However, if Ca and Mg are removed prior to RF adsorption process by precipitation, the negative effect of these ions on Sr removal can be significantly reduced.
Sountharajah, DP, Kus, B, Kandasamy, J & Vigneswaran, S 2017, 'Quantifying the reduction in water demand due to rainwater tank installations at residential properties in sydney', Journal of Sustainable Development of Energy, Water and Environment Systems, vol. 5, no. 2, pp. 202-218.View/Download from: UTS OPUS or Publisher's site
© 2017, International Centre for Sustainable Development of Energy, Water and Environment Systems SDEWES. All rights reserved. This paper examines data on actual reductions in consumption of water supply due to the widespread installation of rainwater tanks at residential properties in the Sydney metropolitan area and surrounding areas connected to Sydney Water Corporation water supply mains. The water consumption was based on metered potable water usage between 2002 and 2009. The number of properties in the study database totalled 962,697 single residential dwellings. Of this a total of 52,576 or 5.5% of Sydney’s households had a rainwater tank registered with Sydney Water Corporation. The water usage consumption before and after the installation of the rainwater tank was analysed to quantify the extent to which rainwater tanks reduced mains water consumption. The average percentage of water savings by installing rainwater tanks across all 44 local government authorities was 9%. In some Sydney localities this reduction was up to 15%. On average, a household was able to save around 24 kilolitre of water annually by installing a rainwater tank even without considering other factors that affect water usage. The results were compared against socio-demographic factors using variables such as household size, educational qualifications, taxable income, rented properties, and non-English-speaking background, etc., to gain an appreciation of how these factors may have influenced the outcomes evident in the data. Among the co-relations found were that most properties within inner Sydney with a rainwater tank achieved at least a 9 to 11% additional reduction in water usage, with more than half of those local government authorities achieving more than 11%; properties with larger land area were more likely to have a rainwater tank installed; local government authorities with more people born in non-English speaking countries had lower reduction in water consumption reduction...
Sounthararajah, DP, Loganathan, P, Kandasamy, J & Vigneswaran, S 2017, 'Removing heavy metals using permeable pavement system with a titanate nano-fibrous adsorbent column as a post treatment.', Chemosphere, vol. 168, pp. 467-473.View/Download from: UTS OPUS or Publisher's site
Permeable pavement systems (PPS) are a widely-used treatment measure in sustainable stormwater management and groundwater recharge. However, PPS are not very efficient in removing heavy metals from stormwater. A pilot scale study using zeolite or basalt as bed material in PPS removed 41-72%, 67-74%, 38-43%, 61-72%, 63-73% of Cd, Cu, Ni, Pb, and Zn, respectively, from synthetic stormwater (pH 6.5; Cd, Cu, Ni, Pb, and Zn concentrations of 0.04, 0.6, 0.06, 1.0, and 2.0 mg L-1, respectively) over a period of 80 h. The total volume of stormwater that passed through the PPS was equivalent to runoff in 10 years of rainfall in Sydney, Australia. The concentrations of metals in the PPS effluent failed fresh and marine water quality trigger values recommended in the Australian and New Zealand guidelines. An addition of a post-treatment of a horizontal filter column containing a titanate nano-fibrous (TNF) material with a weight < 1% of zeolite weight and mixed in with granular activated carbon (GAC) at a GAC:TNF weight ratio of 25:1 removed 77% of Ni and 99-100% of all the other metals. The effluent easily met the required standards of marine waters and just met those concerning fresh waters. Batch adsorption data from solutions of metals mixtures fitted the Langmuir model with adsorption capacities in the following order, TNF ≫ zeolite > basalt; Pb > Cu > Cd, Ni, Zn.
Kalaruban, M, Loganathan, P, Kandasamy, J, Naidu, R & Vigneswaran, S 2017, 'Enhanced removal of nitrate in an integrated electrochemical-adsorption system', Separation and Purification Technology, vol. 189, pp. 260-266.View/Download from: UTS OPUS or Publisher's site
© 2017 Elsevier B.V. The electrochemical (EC) method of removing pollutants in water is a widely used process in water and wastewater treatment. An EC-adsorption integrated system was investigated to test whether the simultaneous removal of nitrate by the two processes would be better than removal utilising the individual EC and adsorption methods. In the integrated system, an adsorbent (ion exchange resin - Dowex 21k XLT) was placed inside a stainless steel box that served as an anode with a Cu plate as cathode. In an experiment using 2 L nitrate solution containing 20 mg N/L and 2 g adsorbent the rate of nitrate removal in the integrated system was initially fast with 35% removed in 30 min, though slowing down later. The rate of removal increased with increasing current, voltage and pH up to 7 but decreased as the distance between the electrodes also increased. The optimum nitrate removal of 67% was obtained at pH 7, 1 A, and 31 V for a distance of 1 cm between the electrodes after 180 min. The amount of nitrate removed fell when sulphate was present in the integrated system due to sulphate competing with nitrate for adsorption. Concentration of ammonium produced by nitrate reduction in the EC system was reduced in the presence of adsorbent. Nitrate removal in the integrated system is approximately equal to the sum of the removals in the two individual processes.
Atiquzzaman, M & Kandasamy, J 2016, 'Prediction of hydrological time-series using extreme learning machine', Journal of Hydroinformatics, vol. 18, no. 2, pp. 345-353.View/Download from: UTS OPUS or Publisher's site
Applying feed-forward neural networks has been limited due to the use of conventional gradient-based slow learning algorithms in training and iterative determination of network parameters. This paper demonstrates a method that partly overcomes these problems by using an extreme learning machine (ELM) which predicts the hydrological time-series very quickly. ELMs, also called single-hidden layer feed-forward neural networks (SLFNs), are able to well generalize the performance for extremely complex problems. ELM randomly chooses a single hidden layer and analytically determines the weights to predict the output. The ELM method was applied to predict hydrological flow series for the Tryggevælde Catchment, Denmark and for the Mississippi River at Vicksburg, USA. The results confirmed that ELM's performance was similar or better in terms of root mean square error (RMSE) and normalized root mean square error (NRMSE) compared to ANN and other previously published techniques, namely evolutionary computation based support vector machine (EC-SVM), standard chaotic approach and inverse approach.
Atiquzzaman, M & Kandasamy, J 2016, 'Prediction of inflows from dam catchment using genetic programming', International Journal of Hydrology Science and Technology, vol. 6, no. 2, pp. 103-117.View/Download from: UTS OPUS or Publisher's site
Copyright © 2016 Inderscience Enterprises Ltd. Application of hydroinformatics tools for managing water resources is common in the water industry. Over the last few decades, several hydroinformatics tools including genetic programming (GP) have been developed and applied in hydrology. GP has been successfully applied for calibration of numerous event-based rainfall and runoff models. However, applying GP to predict long-term time series for the management of water resources is limited. This study demonstrates GP's application in long-term prediction of catchment runoff concerning a dam located in Oberon, New South Wales, Australia. The calibration showed excellent agreement between the observed and simulated flows recorded over 30 years. The model was then applied for the assessment of catchment yields for a future 100 years flows based on two assumed climatic scenarios.
Singkran, N & Kandasamy, J 2016, 'Developing a strategic flood risk management framework for Bangkok, Thailand', Natural Hazards, vol. 84, no. 2, pp. 933-957.View/Download from: UTS OPUS or Publisher's site
This study explains deficiencies in Bangkok’s current floodplain management and demonstrates improvements that are possible using a strategic flood risk management framework. The flood that occurred in 2001 in Bangkok is described with the aim of highlighting the deficiencies of the metropolis’ flood management. A preliminary assessment of flood risks was conducted in each of 50 districts of Bangkok. The flood risk estimation over a 12-year period (1999–2009 and 2011) revealed that 10, 3, 6, and 31 districts of the metropolis were categorized as areas with very high (>30 %), high (>20–30 %), moderate (10–20 %), and low (<10 %) flood risks, respectively. This assessment provides quantitative insight, to compliment the observations made in the 2011 flood, and highlights the motivation behind Bangkok’s current flood management practice. The major findings obtained are as follows. First, the existing flood risk management practices for Bangkok are inefficient and need improvement. Second, the districts having different flood risks reflect the land values and the current flood protection procedures. Third, community participation in processes under the flood risk management framework is important to eliminate conflicts and garner public support and acceptance. Fourth, land use planning and development controls should be integrated with floodplain management plans to properly manage future flood risk. Fifth, a further study should be conducted to determine the uncertainties of future flood risks related to future development expansion and land values across Bangkok.
Abdul, JM, Vigneswaran, S, Kandasamy, J & Mahinthakumar, G 2016, 'Fenton Oxidation of Metsulfuron-Methyl with Application to Permeable Reactive Barriers', Environmental Modeling and Assessment, vol. 21, no. 1, pp. 149-158.View/Download from: UTS OPUS or Publisher's site
© 2015, Springer International Publishing Switzerland. Laboratory experiments were conducted for removal of metsulfuron-methyl (MeS) by Fenton oxidation using a sand column with multiple sampling points and varied flow rates. The transport and degradation of MeS in a sand column were modeled using an advection diffusion reaction system with rate-limited sorption, hydrolysis and second-order degradation kinetics. Rate constants for MeS adsorption and degradation were obtained by fitting the model to experimental breakthrough curves. Results showed that the residence time is the primary influencing factor in the amount of MeS removal by Fenton oxidation with removal efficiencies exceeding 85 %. The column model was extended to two-dimensional porous media, and simulations were conducted to evaluate the feasibility of in situ chemical oxidation using Fenton’s reagent in permeable reactor barriers. Results show that Fenton oxidation can yield remediation efficiencies exceeding 80 % in permeable reactor barriers when compared to less than 10 % with adsorption only.
Jeong, S, Tien, VN, Vigneswaran, S, Kandasamy, J & Dharmabalan, D 2016, 'Removal of natural organic matter at the Gunbower water treatment plant in northern Victoria, Australia', DESALINATION AND WATER TREATMENT, vol. 57, no. 20, pp. 9061-9069.View/Download from: UTS OPUS or Publisher's site
Johir, MAH, Shim, WG, Pradhan, M, Vigneswaran, S & Kandasamy, J 2016, 'Benefit of adding adsorbent in submerged membrane microfiltration treatment of wastewater', Desalination and Water Treatment, vol. 57, no. 44, pp. 20683-20693.View/Download from: Publisher's site
In this study, the effect of coupling ion-exchange resin (purolite) and powdered activated carbon (PAC) in a submerged membrane reactor was investigated in terms of (i) removal of different classes of organic matter and (ii) reduction of membrane fouling. The degree of fouling in a membrane hybrid system was modelled in terms of transmembrane pressure development and organic removal efficiency using a simple semi-empirical model. Among these three absorbents, PAC was the most effective with higher removal efficiency for DOC (almost 100% reduction of hydrophobic organic compounds). Excitation–emission matrix analysis and LC–OCD were employed for the detailed organic characterisation.
Vigneswaran, S, Kandasamy, J & Johir, MAH 2016, 'Sustainable Operation of Composting in Solid Waste Management', Procedia Environmental Sciences, vol. 35, pp. 408-415.View/Download from: UTS OPUS or Publisher's site
Naidu, G, Nur, T, Loganathan, P, Kandasamy, J & Vigneswaran, S 2016, 'Selective sorption of rubidium by potassium cobalt hexacyanoferrate', SEPARATION AND PURIFICATION TECHNOLOGY, vol. 163, pp. 238-246.View/Download from: UTS OPUS or Publisher's site
Nur, T, Loganathan, P, Kandasamy, J & Vigneswaran, S 2016, 'Phosphate Adsorption from Membrane Bioreactor Effluent Using Dowex 21K XLT and Recovery as Struvite and Hydroxyapatite', INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH, vol. 13, no. 3.View/Download from: UTS OPUS or Publisher's site
Nur, T, Naidu, G, Loganathan, P, Kandasamy, J & Vigneswaran, S 2016, 'Rubidium recovery using potassium cobalt hexacyanoferrate sorbent', DESALINATION AND WATER TREATMENT, vol. 57, no. 55, pp. 26577-26585.View/Download from: UTS OPUS or Publisher's site
Sounthararajah, DP, Loganathan, P, Kandasamy, J & Vigneswaran, S 2016, 'Column studies on the removal of dissolved organic carbon, turbidity and heavy metals from stormwater using granular activated carbon', DESALINATION AND WATER TREATMENT, vol. 57, no. 11, pp. 5045-5055.View/Download from: UTS OPUS or Publisher's site
Naidu, G, Loganathan, P, Jeong, S, Johir, MAH, Vu, HPT, Kandasamy, J & Vigneswaran, S 2016, 'Rubidium extraction using an organic polymer encapsulated potassium copper hexacyanoferrate sorbent', CHEMICAL ENGINEERING JOURNAL, vol. 306, pp. 31-42.View/Download from: UTS OPUS or Publisher's site
Johir, MAH, Pradhan, M, Loganathan, P, Kandasamy, J & Vigneswaran, S 2016, 'Phosphate adsorption from wastewater using zirconium (IV) hydroxide: Kinetics, thermodynamics and membrane filtration adsorption hybrid system studies', JOURNAL OF ENVIRONMENTAL MANAGEMENT, vol. 167, pp. 167-174.View/Download from: UTS OPUS or Publisher's site
Kalaruban, M, Loganathan, P, Shim, WG, Kandasamy, J, Naidu, G, Tien, VN & Vigneswaran, S 2016, 'Removing nitrate from water using iron-modified Dowex 21K XLT ion exchange resin: Batch and fluidised-bed adsorption studies', SEPARATION AND PURIFICATION TECHNOLOGY, vol. 158, pp. 62-70.View/Download from: UTS OPUS or Publisher's site
Kalaruban, M, Loganathan, P, Shim, WG, Kandasamy, J, Ngo, HH & Vigneswaran, S 2016, 'Enhanced removal of nitrate from water using amine-grafted agricultural wastes', SCIENCE OF THE TOTAL ENVIRONMENT, vol. 565, pp. 503-510.View/Download from: UTS OPUS or Publisher's site
Aryal, R, Furumai, H, Nakajima, F, Beecham, S & Kandasamy, J 2015, 'Characterisation of Prolonged Deposits of Organic Matter in Infiltration System Inlets and Their Binding with Heavy Metals: a PARAFAC Approach', WATER AIR AND SOIL POLLUTION, vol. 226, no. 6.View/Download from: Publisher's site
Aryal, R, Lee, B-K, Beecham, S, Kandasamy, J, Aryal, N & Parajuli, K 2015, 'Characterisation of Road Dust Organic Matter as a Function of Particle Size: A PARAFAC Approach', WATER AIR AND SOIL POLLUTION, vol. 226, no. 2.View/Download from: Publisher's site
Pradhan, M, Vigneswaran, S & Kandasamy, J 2015, 'Assessment of fouling behaviour in submerged microfiltration system coupled with flocculation', JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY, vol. 21, pp. 254-260.View/Download from: Publisher's site
Shanmuganathan, S, Johir, MAH, Tien, VN, Kandasamy, J & Vigneswaran, S 2015, 'Experimental evaluation of microfiltration-granular activated carbon (MF-GAC)/nano filter hybrid system in high quality water reuse', JOURNAL OF MEMBRANE SCIENCE, vol. 476, pp. 1-9.View/Download from: UTS OPUS or Publisher's site
Shanmuganathan, S, Nguyen, TV, Jeong, S, Kandasamy, J & Vigneswaran, S 2015, 'Submerged membrane – (GAC) adsorption hybrid system in reverseosmosis concentrate treatment', Separation and Purification Technology, vol. 146, pp. 8-14.View/Download from: UTS OPUS or Publisher's site
Wastewater reclamation plants using reverse osmosis as the final polishing treatment produce reverse osmosis concentrate (ROC), which consists of high salinity, nutrients and (recalcitrant) organics. The ROC collected from the water reclamation plant in Sydney was treated with a micro filtration (MF)–GAC hybrid system that removed natural and synthetic organics prior to its discharge into the environment. The MF–GAC hybrid system’s performance was studied in terms of trans-membrane pressure (TMP) development, and organics removal. These features were measured using liquid chromatography–organic carbon detection (LC–OCD), Fluorescence Excitation-Emission matrix (F-EEM), and Liquid chromatography with tandem mass spectroscopy (LC–MS). Adding GAC into the membrane reactor reduced the TMP by reducing membrane fouling both through mechanical scouring and pre-adsorption of organics. F-EEM confirms the removal of humics-like and fulvic-like compounds by GAC from ROC. Pharmaceuticals and personal care products (PPCPs) were also removed by the MF–GAC hybrid system
Shrestha, A, Johir, MAH, Vigneswaran, S & Kandasamy, J 2015, 'A comparative study on in-line flocculation and spiral flocculation followed by media filtration as a pre-treatment of seawater', Desalination and Water Treatment, vol. 55, no. 4, pp. 892-900.View/Download from: Publisher's site
© 2014 Balaban Desalination Publications. All rights reserved. Abstract: In this study the efficiency of two different flocculation systems namely in-line flocculation and spiral flocculation followed by media filtration (sand or anthracite) have been investigated as a pre-treatment of seawater to reverse osmosis. The performances of these filtration systems were assessed in terms of turbidity removal, head loss development, ultra filter-modified fouling index (UF-MFI) and organic matters removal. Both systems showed 60–70% removal of turbidity. In-line flocculation and filtration showed 2–3 times higher head loss development than spiral flocculation filtration. These filtration systems helped to reduce the fouling potential (in terms of UF-MFI) by 50–73%, whereas dissolved organic carbon-removal efficiency was 30–45%. The fractionation of organic matter showed that both systems removed 70% of hydrophobic organic matters. The removals of hydrophilic organics were around 30–40%. Among the hydrophilic compounds, the removal of biopolymer and lower molecular weight neutrals and acid were higher than that of humic substances’ and building blocks’.
Nur, T, Shim, WG, Loganathan, P, Vigneswaran, S & Kandasamy, J 2015, 'Nitrate removal using Purolite A520E ion exchange resin: batch and fixed-bed column adsorption modelling', International Journal of Environmental Science and Technology, vol. 12, no. 4, pp. 1311-1320.View/Download from: UTS OPUS or Publisher's site
Removing excessive nitrate from water is essential because it causes eutrophication which in turn has a harmful effect on aquatic life, resulting in a reduction in biodiversity and posing a danger to peoples health when the water is used for drinking. In this study, nitrate removal from aqueous solutions was studied using an ion exchange resin (Purolite A520E) in batch and fixed-bed column experiments. Batch adsorption kinetics was very well described by pseudo-first-order, pseudo-second-order and homogeneous surface diffusion models for resin doses 1.5 and 3.0 g/L at a nitrate concentration 20 mg N/L. Column kinetic data satisfactorily fitted to the empirical Thomas model and a numerical model based on advection dispersion equation for filtration velocities 2.5 and 5.0 m/h at a column height of 12 cm and inlet concentration 20 mg N/L. The experimental and Thomas model predicted breakthrough adsorption capacity ranges for the two filtration rates were 12.013.5 and 8.29.7 mg N/g, respectively, whereas the maximum adsorption capacity determined using Langmuir adsorption isotherm model in the batch study was 32.2 mg N/g.
Sounthararajah, DP, Loganathan, P, Kandasamy, J & Vigneswaran, S 2015, 'Adsorptive removal of heavy metals from water using sodium titanate nanofibres loaded onto GAC in fixed-bed columns', JOURNAL OF HAZARDOUS MATERIALS, vol. 287, pp. 306-316.View/Download from: UTS OPUS or Publisher's site
Sounthararajah, DP, Loganathan, P, Kandasamy, J & Vigneswaran, S 2015, 'Effects of Humic Acid and Suspended Solids on the Removal of Heavy Metals from Water by Adsorption onto Granular Activated Carbon', INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH, vol. 12, no. 9, pp. 10475-10489.View/Download from: UTS OPUS or Publisher's site
Nguyen, TC, Loganathan, P, Nguyen, TV, Pham, TTN, Kandasamy, J, Wu, M, Naidu, R & Vigneswaran, S 2015, 'Trace elements in road-deposited and waterbed sediments in Kogarah Bay, Sydney: enrichment, sources and fractionation', Soil Research, vol. 53, no. 4, pp. 401-411.View/Download from: UTS OPUS or Publisher's site
Road-deposited sediments (RDS) are a potential source of trace elements (TE) that can be transported by stormwater to neighbouring water bodies and cause aquatic pollution. A study in Sydney, Australia showed that of the 11 TE analysed, Zn, Cu, V, Cr, and Sb were greatly enriched in RDS compared to those in baseline soils (BS). All TE concentrations in water bed-sediments (WBS) in the catchment area were similar to those in the BS. Correlation and principal component analyses revealed that of the five TE enriched in RDS, Zn, Cu, Cr and Sb were related to each other, and they probably originated from vehicle components such as tyres and brake linings. Vanadium was separated into another component, likely to have originated mainly from road surface asphalt abrasion. Trace element concentrations in the mobile fraction of RDS, determined using a sequential extraction method, were: Fe >Mn, Zn > Cu, Pb> Cr, Ni, V, Cd, Sb. However, this fraction as a percentage of total elemental concentration was highest for Cd and Zn and lowest for Fe, Cr, Ni, and V. The RDS sites had low-medium ecological risk whereas WBS and BS sites had low risk.
Shanmuganathan, S, Vigneswaran, S, Nguyen, TV, Loganathan, P & Kandasamy, J 2015, 'Use of nanofiltration and reverse osmosis in reclaiming micro-filtered biologically treated sewage effluent for irrigation', DESALINATION, vol. 364, pp. 119-125.View/Download from: UTS OPUS or Publisher's site
Thankappan, R, Nguyen, TV, Srinivasan, SV, Vigneswaran, S, Kandasamy, J & Loganathan, P 2015, 'Removal of leather tanning agent syntan from aqueous solution using Fenton oxidation followed by GAC adsorption', JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY, vol. 21, pp. 483-488.View/Download from: UTS OPUS or Publisher's site
Thuy, CN, Loganathan, P, Tien, VN, Vigneswaran, S, Kandasamy, J & Naidu, R 2015, 'Simultaneous adsorption of Cd, Cr, Cu, Pb, and Zn by an iron-coated Australian zeolite in batch and fixed-bed column studies', CHEMICAL ENGINEERING JOURNAL, vol. 270, pp. 393-404.View/Download from: UTS OPUS or Publisher's site
Chanan, AP, Vigneswaran, S, Kandasamy, JK & Singh, G 2014, 'Beverley Park water reuse plant: getting the salt just right', Desalination and Water Treatment, vol. 52, no. 25-27, pp. 4656-4663.View/Download from: Publisher's site
The extraction type wastewater recycling systems are those where wastewater is taken from the collection system en route to the central treatment plant. This paper discusses a case study of Sydneys first ever extraction type scheme, the Beverley Park water reuse scheme. Primary applications of recycled water from this case study site include: parks and ovals, green-belt and golf course irrigation. Given the plants location on a major interceptor sewer along Kogarah Bay, tidal influx posed a significant challenge due to high salt levels. Salt sensitive grass on golf course greens meant that treated water had to meet stringent quality requirements with regards to salt. The design involved modelling the process of diurnal fluctuations in salt levels and to provide an optimised process design. A non-membrane, design based solution was also chosen to resolve this high salinity challenge. This Case Study highlights the significant challenges in planning, design and commissioning of water reuse plant intercepting sewer carriers prone to salt water intrusion. The study provides valuable knowledge that will assist in providing viable extraction type water reuse schemes for tidal impacted areas.
Pradhan, M, Vigneswaran, S, Ben Aim, R & Kandasamy, JK 2014, 'Modelling of particle deposition in a submerged membrane microfiltration system', Desalination, vol. 350, pp. 14-20.View/Download from: UTS OPUS or Publisher's site
Shanmuganathan, S, Nguyen, V, Shim, W, Kandasamy, JK & Vigneswaran, S 2014, 'Performance of submerged membrane - Ion exchange hybrid system with Purolite A502PS in treating reverse osmosis feed', Separation and Purification Technology, vol. 122, pp. 24-31.View/Download from: UTS OPUS or Publisher's site
Shanmuganathan, S, Tien, VN, Shim, WG, Kandasamy, J, Listowski, A & Vigneswaran, S 2014, 'Effluent organic matter removal from reverse osmosis feed by granular activated carbon and purolite A502PS fluidized beds', JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY, vol. 20, no. 6, pp. 4499-4508.View/Download from: UTS OPUS or Publisher's site
Shrestha, A, Jeong, S, Vigneswaran, S & Kandasamy, JK 2014, 'Seawater biofiltration pre-treatment system: comparison of filter media performance', Desalination and Water Treatment, vol. 52, no. 34-36.View/Download from: UTS OPUS or Publisher's site
Biological filtration is an effective pre-treatment method to remove organic matter and particulate matter from seawater. Three biofilter columns were operated packed with granular-activated carbon (GAC), anthracite and sand as a filter media. The biofilters were run for 120 d at a slow filtration velocity of 0.12?m/h. Biofiltration performances were evaluated in terms of turbidity, different fouling indices, and dissolved organic carbon(DOC). The removal efficiencies of turbidity by the three biofilters were similar with low headloss development. The fouling potential of treated seawater (filtrate) was evaluated using three different fouling indices such as microfiltration, ultrafiltration, and microfiltration at a cross flow. The analyses of three different fouling indices showed that the reduction in fouling potential was the following order GAC?>?sand?>?anthracite. In terms of DOC removal efficiency, GAC biofilter showed higher and stable removal efficiency (4188%), than sand biofilter (776%) and anthracite biofilter (371%). All biofilters used in this study removed most of hydrophobic organic compounds (around 94%). On the other hand, hydrophilic organic removal varied depending on the media filter. GAC biofilter removed more organic biopolymers (51%), humic substances (75%) and building blocks (50%) compared with sand and anthracite biofilters. Therefore, GAC biofiltration can be used as an effective pre-treatment to alleviate organic fouling.
van Emmerik, THM, Li, Z, Sivapalan, M, Pande, S, Kandasamy, J, Savenije, HHG, Chanan, A & Vigneswaran, S 2014, 'Socio-hydrologic modeling to understand and mediate the competition for water between agriculture development and environmental health: Murrumbidgee River basin, Australia', Hydrology and Earth System Sciences, vol. 18, no. 10, pp. 4239-4259.View/Download from: UTS OPUS or Publisher's site
Competition for water between humans and ecosystems is set to become a flash point in the coming decades in many parts of the world. An entirely new and comprehensive quantitative framework is needed to establish a holistic understanding of that competition, thereby enabling the development of effective mediation strategies. This paper presents a modeling study centered on the Murrumbidgee River basin (MRB). The MRB has witnessed a unique system dynamics over the last 100 years as a result of interactions between patterns of water management and climate driven hydrological variability. Data analysis has revealed a pendulum swing between agricultural development and restoration of environmental health and ecosystem services over different stages of basin-scale water resource development. A parsimonious, stylized, quasi-distributed coupled socio-hydrologic system model that simulates the two-way coupling between human and hydrological systems of the MRB is used to mimic and explain dominant features of the pendulum swing. The model consists of coupled nonlinear ordinary differential equations that describe the interaction between five state variables that govern the co-evolution: reservoir storage, irrigated area, human population, ecosystem health, and environmental awareness. The model simulations track the propagation of the external climatic and socio-economic drivers through this coupled, complex system to the emergence of the pendulum swing. The model results point to a competition between human "productive" and environmental "restorative" forces that underpin the pendulum swing. Both the forces are endogenous, i.e., generated by the system dynamics in response to external drivers and mediated by humans through technology change and environmental awareness, respectively. Sensitivity analysis carried out with the model further reveals that socio-hydrologic modeling can be used as a tool to explain or gain insight into observed co-evolutionary dynamics of diver...
Nur, T, Johir, MAH, Loganathan, P, Nguyen, T, Vigneswaran, S & Kandasamy, J 2014, 'Phosphate removal from water using an iron oxide impregnated strong base anion exchange resin', Journal of Industrial and Engineering Chemistry, vol. 20, pp. 1301-1307.View/Download from: UTS OPUS or Publisher's site
Removing phosphate from water is important as it causes eutrophication, which in turn has a harmful effect on aquatic life, resulting in a reduction in biodiversity. On the other hand, recovery of phosphate from phosphorus containing wastewater is essential for developing an alternative source of phosphorus to overcome the global challenge of phosphorus scarcity. Phosphate removal from aqueous solutions was studied using an iron oxide impregnated strong base anion exchange resin, Purolite FerrIX A33E in batch and fixed-bed column experiments. Phosphate adsorption in the batch study satisfactorily fitted to the Langmuir isotherm with a maximum adsorption capacity of 48 mg P/g. In the column study, increase in inlet phosphate concentration (530 mg P/L), and filtration velocity (2.510 m/h) resulted in faster breakthrough times and increase in breakthrough adsorption capacities. Increase in bed height (3 19 cm) also increased adsorption capacity but the breakthrough time was slower. The breakthrough data were reasonably well described using the empirical models of BohartAdams, Thomas, and Yoon Nelson, except for high bed heights. Phosphate adsorbed was effectively desorbed using 1 M NaOH and the adsorbent was regenerated after each of three adsorption/desorption cycles by maintaining the adsorption capacity at >90% of the original value. Greater than 99.5% of the desorbed P was recovered by precipitation using CaCl2.
Nur, T, Loganathan, L, Nguyen, T, Vigneswaran, S, Singh, G & Kandasamy, JK 2014, 'Batch and column adsorption and desorption of fluoride using hydrous ferric oxide: Solution chemistry and modelling', Chemical Engineering Journal, vol. 247, pp. 93-102.View/Download from: UTS OPUS or Publisher's site
Nur, T, Shim, WG, Johir, MAH, Vigneswaran, S & Kandasamy, J 2014, 'Modelling of phosphorus removal by ion-exchange resin (Purolite FerrIX A33E) in fixed-bed column experiments', Desalination and Water Treatment, vol. 52, no. 4-6, pp. 784-790.View/Download from: UTS OPUS or Publisher's site
Phosphorus removal is important as it causes eutrophication that in turn has a harmful effect on fish and other aquatic life, resulting in a reduction in biodiversity as well as unfavourable human environmental health. In this study, phosphorus removal from aqueous solutions was studied using an ion-exchange resin (Purolite FerrIX A33E) in fixed-bed column experiments. The effects of adsorbent bed height (319 cm) on the breakthrough characteristics of the adsorption system were studied. An increase in bed height (319 cm) increased adsorption capacity but the breakthrough time was shorter. As the bed height increased, the detention time increased and the phosphate was in contact with the purolite ion-exchange resin for a longer time, resulting in more efficient removal of phosphate. The shape of breakthrough curve was steeper for a shorter bed height. A mathematical model (advection dispersion equation) was solved numerically to predict the dynamic behaviour of the columns. Finally, sensitivity analysis results apparently revealed that the dynamic adsorption behaviours of phosphate in Purolite FerrIX A33E were mainly controlled by the external mass transfer rather than the axial dispersion and the intra-particle diffusion.
Kandasamy, JK, Sounthararajah, DP, Sivabalan, P, Chanan, A, Vigneswaran, S & Sivapalan, M 2014, 'Socio-hydrologic drivers of the pendulum swing between agricultural development and environmental health: a case study from Murrumbidgee River basin, Australia', Hydrology And Earth System Sciences, vol. 18, no. 3, pp. 1027-1041.View/Download from: UTS OPUS or Publisher's site
Loganathan, P, Vigneswaran, S, Kandasamy, J & Bolan, NS 2014, 'Removal and Recovery of Phosphate From Water Using Sorption', CRITICAL REVIEWS IN ENVIRONMENTAL SCIENCE AND TECHNOLOGY, vol. 44, no. 8, pp. 847-907.View/Download from: UTS OPUS or Publisher's site
Nguyen, T, Loganathan, L, Nguyen, V, Vigneswaran, S, Kandasamy, JK, Slee, S, Gavin, S & Naidu, R 2014, 'Polycyclic aromatic hydrocarbons in road-deposited sediments, water sediments, and soils in Sydney, Australia: Comparisons of concentration distribution, sources and potential toxicity', Ecotoxicology And Environmental Safety, vol. 104, pp. 339-348.View/Download from: UTS OPUS or Publisher's site
Tien, VN, Jeong, S, Thi, TNP, Kandasamy, J & Vigneswaran, S 2014, 'Effect of granular activated carbon filter on the subsequent flocculation in seawater treatment', DESALINATION, vol. 354, pp. 9-16.View/Download from: UTS OPUS or Publisher's site
Chekli, L, Phuntsho, S, Kandasamy, J & Shon, H 2013, 'Assessing the aggregation behaviour of iron oxide nanoparticles by using a multi-method approach.', Technical Proceedings of the 2013 NSTI Nanotechnology Conference and Expo, NSTI-Nanotech 2013, vol. 1, pp. 47-50.View/Download from: UTS OPUS
Iron nanoparticles are becoming increasingly popular for the treatment of contaminated soil and groundwater; however, their mobility and reactivity in subsurface environments are significantly affected by their tendency to aggregate. Assessing their stability under environmental conditions is crucial for determining their environmental fate. A multi-method approach (including different size-measurement techniques) was used to thoroughly characterise the behaviour of iron oxide nanoparticles (Fe2O3NPs) under environmentally relevant conditions. Although recent studies have demonstrated the importance of using a multi-method approach when characterising nanoparticles, the majority of current studies continue to use a single-method approach. Discussions and examples to support the need of a multi-method approach to characterise the aggregation of nanoparticles will be presented in this study.
Jeong, S, Kim, S, Kim, CM, Vigneswaran, S, Nguyen, V, Shon, H, Kandasamy, JK & Kim, IS 2013, 'A detailed organic matter characterization of pretreated seawater using low-pressure microfiltration hybrid systems', Journal Of Membrane Science, vol. 428, pp. 290-300.View/Download from: UTS OPUS or Publisher's site
In this study, two different submerged membrane hybrid systems (SMHSs) namely (i) submerged membrane coagulation hybrid system (SMCHS) and (ii) submerged membrane coagulation-adsorption hybrid system (SMCAHS) were investigated as pretreatment options for seawater reverse osmosis. Organic matters in seawater before and after pretreatment were characterized in terms of XAD fractionation, molecular weight distribution (MWD) and fluorescence. A detailed study on the seawater organic matter (SWOM) structure was made through 1H-nuclear magnetic resonance (1H NMR), pyrolysis-gas chromatographyâmass spectrometry (Py-GC/MS) and liquid chromatography-mass spectrometry-ion trap-time of fright (LC/MS-IT-TOF). The seawater investigated in this study is mainly composed of hydrophilic matter (5773.2%). SMHSs removed a significant amount of organic matter. The EEM fluorescence showed a removal of humic-like materials by SMHSs. In addition, humic-like materials relative to protein-like compounds were reduced significantly but the aromaticity of humic-like materials increased. After pretreatment by SMHSs, humics and biopolymers of over 900 Da. were found to be reduced and their structure associated with element composition was also changed. The transformation of the SWOM structure after SMHSs pretreatment may have been due to hydrolyzation or oxidization of the organic compounds such as humics and biopolymers resulting in poly-conjugation to aromatic compounds. SMHSs were effective in improving the RO performance leading to higher RO permeate flux and lower permeate flux decline. The pretreatment reduced the amount of foulants on the RO membrane.
Kus, BG, Kandasamy, JK, Vigneswaran, S, Shon, H & Moody, G 2013, 'Gravity driven membrane filtration system to improve the water quality in rainwater tanks', Water Science & Technology: Water Supply, vol. 13, no. 2, pp. 479-485.View/Download from: UTS OPUS or Publisher's site
The characterisation of rainwater in metropolitan Sydney and in rural New South Wales was undertaken. The results showed that factors such as the lack of vehicular traffic, air pollution and urban contamination meant that rural rainwater water quality was better. The rain water collected in both metropolitan and rural areas generally complied with the 2004 Australian Drinking Water Guidelines except for parameters such as the pH in both the metropolitan and rural rainwater tanks and the turbidity, and lead levels from the metropolitan tanks. This paper also reports the results of a laboratory and a pilot scale study with a deep bed filter (granular activated carbon, GAC) and microfiltration (MF) hollow fibre membrane filter system used to treat raw rainwater collected from a metropolitan rainwater tank. The results of the laboratory experiment and pilot scale systems focus on the non-compliant parameters of the sampling program, i.e. turbidity, lead and dissolved organic carbon (DOC). It was found that rainwater treated by the GAC filter removed the majority of the turbidity and organic substances. The treatment system reduced the concentration of turbidity, lead and DOC to below the Australian Drinking Water Guidelines limits. The pilot plant experiment demonstrated that a GAC filter system and gravity driven membrane could result in low cost and low maintenance operation.
Kus, BG, Kandasamy, JK, Vigneswaran, S, Shon, H & Moody, G 2013, 'Household rainwater harvesting system - Pilot scale gravity driven membrane-based filtration system', Water Science & Technology: Water Supply, vol. 13, no. 3, pp. 790-797.View/Download from: UTS OPUS or Publisher's site
This paper presents the results of a pilot scale study consisting of pre-treatment with a granular activated carbon (GAC) filter followed by membrane filtration. Detailed characterisation of rainwater tanks has highlighted that turbidity, dissolved organic carbon (DOC) and heavy metals, in particular lead, were not compliant with the 2004 Australian Drinking Water Guidelines (ADWG). Further, organic matter present in the water causes membrane fouling and leads to carcinogenic compounds upon chlorination. A GAC filter was used as a first step to remove dissolved organic matter (measured in terms of DOC) in particular and also to reduce the concentration, of turbidity and lead. Membrane filtration can remove any remaining solids reducing the concentrations of turbidity and microorganisms. In this study a pilot scale rainwater treatment system consisting of a gravity fed GAC filter and membrane filter (Ultra Flo) was operated for a period of 120 days. The performance of this system was assessed in terms of membrane flux and improvement in water quality measured against the 2004 Australian Drinking Water Guidelines. Determination of the flux especially in the later stages of membrane operation was important to be able to size the filters in a manner that meets the expected demand. The treatment system of GAC filter and membrane filter was effective in reducing the turbidity, DOC and heavy metals. The system reduced the turbidity to levels of 0.30.4 NTU, below the ADWG limit of 1 NTU.
Aryal, R, Beecham, SC, Vigneswaran, S, Kandasamy, JK & Naidu, R 2013, 'Spatial variation of polycyclic aromatic hydrocarbons and equivalent toxicity in Sydney Harbour, Australia', Journal of Water and Climate Change, vol. 4, no. 4, pp. 364-372.View/Download from: Publisher's site
Harbour sediments include wash-off from different nearby catchments that have various landuse activities. In this study the spatial variation of polycyclic aromatic hydrocarbons (PAHs) in Sydney Harbour was studied by analysing the sediment. The sediment
Chanan, AP, Vigneswaran, S, Kandasamy, JK & Johir, M 2013, 'Need for a fresh look at phosphorus management in wastewater treatment: Trash to treasure', Sustainable Environment Research, vol. 23, no. 1, pp. 23-31.View/Download from: UTS OPUS
Eutrophication of water bodies is a major, global environmental problem. It is now well understood that its main cause is excessive amounts of nutrients such as phosphorus. Stringent laws were therefore introduced across the world, requiring that the level of the P be significantly reduced. Consequently, the focus for wastewater treatment industry became the elimination of phosphorus in effluent stream. Treatment technologies capable of removing over 90% of phosphorus from wastewater have now been developed. However, these phosphorus removal options are likely to be ineffective in the future. The future would call for a shift to the primary goal of phosphorus removal to 'capturing and reusing' phosphorus. This paper calls for a re-think in developing phosphorus management programs. Discussing Fertigation as step-one in phosphorus reclamation, the paper will further elaborate phosphorus recovery opportunities such as ion-exchange that can be retrofitted to existing wastewater treatment plants.
Johir, M, Shanmuganathan, S, Vigneswaran, S & Kandasamy, JK 2013, 'Performance of submerged membrane bioreactor (SMBR) with and without the addition of the different particle sizes of GAC as suspended medium', Bioresource Technology, vol. 141, pp. 13-18.View/Download from: UTS OPUS or Publisher's site
In this study the effect of different particle sizes of granular activated carbon (GAC) on the performance of a submerged membrane bioreactor (SMBR) was investigated. The sizes of GAC used were 150300, 300600 and 6001200 µm. The SMBR was operated at a filtration flux of 20 L/m2 h. The removal of dissolved organic carbon (DOC) and chemical oxygen demand (COD) with the addition of GAC was 95%. The concentration of biopolymers, humic, building block and low molecular weight neutral and acids in the SMBR effluent was reduced by 20%, 6676%, 2050%, 3056%, respectively. It helped to reduce the sludge volume index (SVI) and transmembrane pressure (TMP) development by 3040% and 58%, respectively. However, the removal of View the MathML source and View the MathML source was relatively low of 3545% and 3443%, respectively. The SMBR effluent was rich in View the MathML source and was removed/recovered using hydrated ferric oxide (HFO). The removal of View the MathML source was almost 90%.
Johir, M, Vigneswaran, S, Kandasamy, JK & Sleigh, R 2013, 'Coupling Of Physico-chemical Treatment And Steel Membrane Filtration To Enhanced Organic Removal In Wastewater Treatment', Desalination And Water Treatment, vol. 51, no. 13-15, pp. 2695-2701.View/Download from: UTS OPUS or Publisher's site
In this study, the application of steel membrane filtration was tested with the pre-treated wastewater. The pre-treatment methods tested before membrane filtration application were flocculation using FeCl3, Powdered Activated Carbon (PAC) adsorption, purolite ion-exchange column and purolite ion-exchange column followed by flocculation (FeCl3). The effect of two different modes of membrane application (cross-flow and dead-end modes) was examined. The ability of these filters in removing organic matters and solids were examined. It was found that the decline of flux was slightly lower for dead-end mode of operation to that of cross-flow mode of operation. Pre-treatment increased the performance of membrane filtration. The flux decline of raw water (without pre-treatment) was 31-10%, whereas after pre-treatment, it was about 2.5-21%. Pre-treatment followed by microfiltration (MF) showed 68-91% removal efficiency of dissolved organic carbon
Johir, M, Vigneswaran, S, Kandasamy, JK, Benaim, R & Grasmick, A 2013, 'Effect of salt concentration on membrane bioreactor (MBR) performances: Detailed organic characterization', Desalination, vol. 322, no. 1, pp. 13-20.View/Download from: UTS OPUS or Publisher's site
The gradual increase of salt concentration (0 to 35 g-NaCl/L) on the performance of membrane bioreactor (MBR) was studied. The uptake rate of dissolved organic carbon and ammonia decreased from around 17.0 mg-DOC/g-MLVSS.d to 1.8 mg-DOC/g-MLVSS.d and from 8.2 mg-NH4-N/g-MLVSS.d to 0 mg-NH4-N/g-MLVSS.d respectively when salt concentration reached to 35 g-NaCl/L. Similarly the specific oxygen uptake rate (SOUR) reduced from 8 to 9 to around 0.3 mg-O2/g-MLVSS.h. The removal of bio-polymers, humic acids, building blocks and low molecular weight neutral decreased with increase in salt concentration. The concentration of dissolved organic nitrogen (DON) in bio-polymer increased from 0.05 to 3.31 mg/L when the salt concentration reached to 35 g-NaCl/L. This study provides good information for understanding the effect of continuous increase of salt concentration in treating saline wastewater in a MBR process.
Loganathan, L, Vigneswaran, S & Kandasamy, JK 2013, 'Enhanced removal of nitrate from water using surface modification of adsorbents - A review', Journal of Environmental Management, vol. 131, no. 1, pp. 363-374.View/Download from: UTS OPUS or Publisher's site
Elevated concentration of nitrate results in eutrophication of natural water bodies affecting the aquatic environment and reduces the quality of drinking water. This in turn causes harm to peoples health, especially that of infants and livestock. Adsorbents with the high capacity to selectively adsorb nitrate are required to effectively remove nitrate from water. Surface modifications of adsorbents have been reported to enhance their adsorption of nitrate. The major techniques of surface modification are: protonation, impregnation of metals and metal oxides, grafting of amine groups, organic compounds including surfactant coating of aluminosilicate minerals, and heat treatment. This paper reviews current information on these techniques, compares the enhanced nitrate adsorption capacities achieved by the modifications, and the mechanisms of adsorption, and presents advantages and drawbacks of the techniques. Most studies on this subject have been conducted in batch experiments. These studies need to include continuous mode column trials which have more relevance to real operating systems and pilot-plant trials. Reusability of adsorbents is important for economic reasons and practical treatment applications. However, only limited information is available on the regeneration of surface modified adsorbents.
Loganathan, L, Vigneswaran, S & Kandasamy, JK 2013, 'Road-deposited sediment pollutants: A critical review of their characteristics, source apportionment, and management', Critical Reviews in Environmental Science and Technology, vol. 43, no. 13, pp. 1315-1348.View/Download from: UTS OPUS or Publisher's site
Road-deposited sediments (RDS) often contain elevated concentrations of inorganic and organic pollutants such as heavy metals, metalloids, and polycyclic aromatic hydrocarbons. The authors trace new developments and trends on RDS pollutant characteristics with respect to their distribution in time and space, total and labile fractions in the different particle size and density fractions, source apportionment, and chemical speciation, as well as on the management of the pollutants. Recent research provides more reliable information to understand pollutants origin, bioavailability, transport pathways, and methods to minimize their risks. Use of special chemical, physical, mineralogical, and statistical methods has contributed to a better understanding of source apportionment of many of the pollutants but more research is needed on others. The degree of accumulation of pollutants in RDS that are derived from roads and vehicles has been quantified by using enrichment factors. Many of the studies on RDS pollutant management dealt with reducing pollutants by road sweeping and water flushing but these have not been found to be very effective. Pollutants that enter the water bodies through stormwater runoff need to be removed to protect the aquatic environment in the receiving water. The current knowledge on stormwater treatment methods to remove pollutants is also presented.
Loganathan, L, Vigneswaran, S, Kandasamy, JK & Naidu, R 2013, 'Defluoridation of drinking water using adsorption processes', Journal of Hazardous Materials, vol. 248-249, pp. 1-19.View/Download from: UTS OPUS or Publisher's site
Excessive intake of fluoride (F), mainly through drinking water, is a serious health hazard affecting humans worldwide. There are several methods used for the defluoridation of drinking water, of which adsorption processes are generally considered attractive because of their effectiveness, convenience, ease of operation, simplicity of design, and for economic and environmental reasons. In this paper, we present a comprehensive and a critical literature review on various adsorbents used for defluoridation, their relative effectiveness, mechanisms and thermodynamics of adsorption, and suggestions are made on choice of adsorbents for various circumstances. Effects of pH, temperature, kinetics and co-existing anions on F adsorption are also reviewed. Because the adsorption is very weak in extremely low or high pHs, depending on the adsorbent, acids or alkalis are used to desorb F and regenerate the adsorbents. However, adsorption capacity generally decreases with repeated use of the regenerated adsorbent. Future research needs to explore highly efficient, low cost adsorbents that can be easily regenerated for reuse over several cycles of operations without significant loss of adsorptive capacity and which have good hydraulic conductivity to prevent filter clogging during the fixed-bed treatment process.
Permeable pavements are generally used in water-sensitive urban design as a component of a treatment train and as a source control measure for reducing stormwater flows and pollutant loads. In Australia, permeable pavement systems are an emerging technology and consequently there are few installations more than 10 years old. The performance of permeable pavements in terms of treatment of urban stormwater runoff from a number of typical, but different urban catchments is discussed. Water quality monitoring was carried out in the field to quantify the improvement that permeable pavement systems can make to runoff quality at a car park located at North Haven in Adelaide, South Australia, that utilise both conventional and permeable pavement systems. Extensive laboratory analysis using stormwater collected from four sites was carried out to assess the effectiveness of permeable pavement systems for reducing pollutant discharges. In general, the permeable pavement systems were found to improve stormwater quality when tested at a 5% significance level. The results show that, on average, permeable pavements were able to reduce nutrient concentrations (total nitrogen and total phosphorus), heavy metals (zinc, lead, copper, cadmium and nickel) and total suspended solids. The reductions in pollutant concentrations can be mainly attributed to mechanical filtration by various components of the permeable pavement system.
Khiadani, M, Beecham, SC & Kandasamy, JK 2012, 'Turbulence Measurements In Spatially-varied Flow With Increasing Discharge', Journal of Hydraulic Research, vol. 50, no. 4, pp. 418-426.View/Download from: UTS OPUS or Publisher's site
This experimental study explores the distribution of Reynolds shear stresses and turbulence intensities for a flume receiving lateral inflow via a set of vertical nozzles. The data set allows for developing turbulence models to describe a wider range of
Pezzaniti, D, Beecham, SC & Kandasamy, JK 2012, 'Stormwater Detention Basin For Improving Road-runoff Quality', Proceedings Of The Institution Of Civil Engineers-water Management, vol. 165, no. 9, pp. 461-471.View/Download from: UTS OPUS or Publisher's site
Both wet and dry detention basins are commonly used for the treatment of road runoff. The basin investigated in this study was located on the eastern side of the southern expressway in Adelaide, Australia. Event mean pollutant concentrations (EMCs) and t
Chekli, L, Phuntsho, S, Shon, H, Vigneswaran, S, Kandasamy, JK & Chanan, AP 2012, 'A Review Of Draw Solutes In Forward Osmosis Process And Their Use In Modern Applications', Desalination and Water Treatment, vol. 43, no. 1-3, pp. 167-184.View/Download from: UTS OPUS or Publisher's site
Forward osmosis (FO) is one of the emerging membrane technologies which has gained renewed interest recently as a low energy desalination process. The central to FO process is the draw solution (DS) and the membrane because both play a substantial role o
Kus, BG, Johir, MH, Kandasamy, JK, Vigneswaran, S, Shon, H, Sleigh, R & Moody, G 2012, 'Performance Of Granular Medium Filtration And Membrane Filtration In Treating Stormwater For Harvesting And Reuse', Desalination and Water Treatment, vol. 45, no. 1-3, pp. 120-127.View/Download from: UTS OPUS or Publisher's site
This paper discusses laboratory scale and pilot scale treatment systems used to in treat water from a stormwater canal in Carlton, Sydney. The laboratory scale pre-treatment systems investigated included flocculation, GAC filtration and fibre filter prior to laboratory scale steriflow stainless steel membrane filter. The results showed that these pre-treatments improved the quality of the filtrate as measured by the turbidity and TOC removal effi ciency. The use of pre-treatment improved the TOC removal efficiency from 10% to 90%. Among the three pretreatment methods, GAC filter resulted in the highest TOC removal efficiency (88%). Pilot scale experiments were also carried out using stainless steel membrane filtration and GAC filtration at Carlton, Sydney. Pilot scale experiments showed that the Steri-Flow membrane filter treatment without any pre-treatment achieved an effluent fi ltrate turbidity of between 0.79â0.99 NTU which were well below the 5 NTU ADWG (2004) limit . The influent raw stormwater had generally low concentrations of heavy metals. Following membrane filtration the concentration of all heavy metals were reduced to very low levels and well within the ADWG (2004)  limits. The membrane fi lter could not remove TOC in significant amounts. GAC adsorption used as post-treatment following Steri-flow membrane treatment effectively reduced the TOC influent feed levels. GAC filtration of stormwater provided a 70% removal of organics. It removed all types of organic. The GAC filter did not provide any further improvement to the turbidity level or heavy metal concentration following treatment with the Steri-flow membrane system.
Kus, BG, Kandasamy, JK, Vigneswaran, S, Shon, H & Moody, G 2012, 'Two Stage Filtration For Stormwater Treatment: A Pilot Scale Study', Desalination and Water Treatment, vol. 45, no. 1-3, pp. 361-369.View/Download from: UTS OPUS or Publisher's site
This paper presents the results of the granular medium filter and membrane (Ultra Flo membrane) filter experiments conducted with raw stormwater collected from a stormwater canal at Carlton, in Sydney. The filter medium experimented were granular activat
Phuntsho, S, Shon, H, Hong, S, Lee, S, Vigneswaran, S & Kandasamy, JK 2012, 'Fertiliser drawn forward osmosis desalination: the concept, performance and limitations for fertigation', Reviews in Environmental Science and Biotechnology, vol. 11, no. 2, pp. 147-168.View/Download from: UTS OPUS or Publisher's site
With the world's population growing rapidly, pressure is increasing on the limited fresh water resources. Membrane technology could play a vital role in solving the water scarcity issues through alternative sources such as saline water sources and wastewater reclamation. The current generation of membrane technologies, particularly reverse osmosis (RO), has significantly improved in performance. However, RO desalination is still energy intensive and any effort to improve energy efficiency increases total cost of the product water. Since energy, environment and climate change issues are all inter-related, desalination for large-scale irrigation requires new novel technologies that address the energy issues. Forward osmosis (FO) is an emerging membrane technology. However, FO desalination for potable water is still a challenge because, recovery and regeneration of draw solutes require additional processes and energy. This article focuses on the application of FO desalination for non-potable irrigation where maximum water is required. In this concept of fertiliser drawn FO (FDFO) desalination, fertilisers are used as draw solutions (DS). The diluted draw solution after desalination can be directly applied for fertigation without the need for recovery and regeneration of DS. FDFO desalination can make irrigation water available at comparatively lower energy than the current desalination technologies. As a low energy technology, FDFO can be easily powered by renewable energy sources and therefore suitable for inland and remote applications. This article outlines the concept of FDFO desalination and critically evaluates the scope and limitations of this technology for fertigation, including suggestions on options to overcome some of these limitations
Phuntsho, S, Vigneswaran, S, Kandasamy, JK, Hong, S, Lee, S & Shon, H 2012, 'Influence of temperature and temperature difference in the performance of forward osmosis desalination process', Journal Of Membrane Science, vol. 415-416, pp. 734-744.View/Download from: UTS OPUS or Publisher's site
Forward osmosis (FO) is an emerging technology for low energy desalination. Amongst the many other factors, emperature of the draw solution (DS) and feed solution (FS) plays an important role in influencing the performance of the FO process. In this study, the influence of the temperature and the temperature difference on the performance of FO process has been studied in terms of water and solute fluxes. Temperature difference was maintained by elevating only one of the solutions (eitherDSorFS). The results indicate that, water flux on average increases by up to 1.2 % for every degree rise in temperature from 25Â°C to 35Â°C while this rise is 2.3% from 25Â°C to 45Â°C. Providing a temperature difference by elevating only the DS also enhanced the water flux significantly, although it was lower than FO process operated at isothermal conditions. However, elevating only the temperature of FS did not significantly improve the water flux although it was higher than the FO process operated at 25Â°C. This as significant implications in FO process because the total mass of the DS requiring heat energy is significantly less than the total FS used. The influences of temperature in the FO process such as through changes in the thermodynamic properties of the solutions and the various concentration polarisation effects are also explained in details.
Ahmad, R, Nguyen, V, Shim, WG, Vigneswaran, S, Moon, H & Kandasamy, JK 2012, 'Effluent Organic Matter Removal By Purolite (R) A500PS: Experimental Performance And Mathematical Model', Separation and Purification Technology, vol. 98, pp. 46-54.View/Download from: UTS OPUS or Publisher's site
In this study, the performance of Purolite(R)A500PS in effluent organic matter (EfOM) removal was evaluated through adsorption equilibrium, kinetics and fluidized bed experiments. It was found that the maximum EfOM removal capacity of PuroliteA500PS calculated by the Langmuir isotherm was 50.9 mg DOC/g PuroliteA500PS. The results also showed that fluidized bed operational conditions strongly affected the EfOM removal efficiency. A fluidized bed packed with PuroliteA500PS can maintain a consistent EfOM removal efficiency of more than 80% with more than 800 bed volumes from 10 mg DOC/L of synthetic wastewater. A majority of hydrophilic compounds (76.4%) and a significant amount of hydrophobic compounds (55%) were removed by the PuroliteA500PS fluidized bed. The Purolite(R)A500PS fluidized bed was also found to remove a majority of biopolymer (98.5%), humic substances (86.5%), and low molecular weight neutrals (83.3%).
Aryal, R, Johir, MH, Vigneswaran, S, Kandasamy, JK & Sleigh, R 2012, 'Performance Of A Stainless Steel Membrane In Membrane Bioreactor Process', Desalination and Water Treatment, vol. 41, no. 1-3, pp. 258-264.View/Download from: UTS OPUS or Publisher's site
Stainless steel membrane has recently emerged as a durable membrane for microfiltration. An aerobic membrane bioreactor (MBR) equipped with a tubular stainless steel membrane of pore size 0.3âÎ¼m was submerged in a wastewater reactor to treat municipal wastewater of about 1,000âmg/L COD. The membrane operational performance was tested at three different permeate flux (7.5, 10 and 15âL/m2âh [LMH]) for 2 days each. In all cases, the rate of transmembrane pressure (TMP) rise was very high at 30, 45 and 80âkPa for 7.5, 10 and 15âLMH, respectively. Different analytical techniques i.e. particle size distribution, UV spectrometry, fluorescent spectrometry and size exclusion chromatography were used to study the nature of mixed liquor and the fouling deposited on the membrane surface. Rapid rise of TMP and decrease in permeate flux was observed during the experiment. Analysis of the fouling indicated a negligible difference in nature of organics between it and the mixed liquor. Filtration flux test showed a high sludge cake and pore-blocking resistance of 4.4âÃâ1019 and 2.8âÃâ1016âmâ1, respectively, compared to a clean membrane resistance 5.4âÃâ1012âmâ1. The similar nature of organics in the mixed liquor and the foulant and recovery of flux after removal of the foulant after gentle washing in water, indicated a rapid sludge accumulation rather than the irreversible fouling.
Chanan, AP, Vigneswaran, S & Kandasamy, JK 2012, 'Case study research: training interdisciplinary engineers with context-dependent knowledge', European Journal of Engineering Education, vol. 37, no. 1, pp. 97-104.View/Download from: Publisher's site
It is now widely acknowledged that water management discipline is transforming, from being a public health and flood prevention challenge of the nineteenth century to a multi-dimensional challenge of water security for the twenty-first century. In order to train water engineers to be capable of working with this holistic multi-dimensional approach, a new paradigm in engineering education is required. Adjustments already made to undergraduate coursework are not enough; this new paradigm requires modifications to the PhD in engineering, with greater emphasis on interdisciplinary case study research. Such a change can deliver PhD graduates with both sufficient social and technical knowledge, who can then go on to become the hybrid lecturers crucially needed for training future water engineers.
Hong, S, Aryal, R, Vigneswaran, S, Johir, MH & Kandasamy, JK 2012, 'Influence of hydraulic retention time on the nature of foulant organics in a high rate membrane bioreactor', Desalination, vol. 287, no. 1, pp. 116-122.View/Download from: UTS OPUS or Publisher's site
The influence of hydraulic retention time (HRT) in a submerged hollow fibre membrane bioreactor was studied by conducting experiments at four different HRTs (4,2, 1.3 and 1 h) at room temperature of 25 Â°C. lt was found that a shorter HRT led to a higher development of trans-membrane pressure. The highest sludge cake and pore-blocking resistances of 4.02 x 1011 m-1 and 0.77 x 1011 m-1 respectively were noted for the shortest HRT (of 1 h) application. UV and fluorescence spectroscopy analyses showed that the nature of organics in the biomass and sludge cakes were different. The organic fraction analysis by liquid chromatography with organic carbon detector (LC-OCO) showed a significant amount of biopolymers and a lower amount of humics for longer HRT.
Johir, M, George, J, Vigneswaran, S, Kandasamy, JK, Sathasivan, AS & Grasmick, A 2012, 'Effect Of Imposed Flux On Fouling Behavior In High Rate Membrane Bioreactor', Bioresource Technology, vol. 122, pp. 42-49.View/Download from: UTS OPUS or Publisher's site
The influence of imposed flux and aeration rates on membrane fouling in a submerged membrane bioreactor was studied. The experiments were conducted at four imposed fluxes and three aeration rates. The effect of flux on the reduction of membrane fouling w
Johir, MH, Vigneswaran, S, Sathasivan, AS, Kandasamy, JK & Chang, C 2012, 'Effect Of Organic Loading Rate On Organic Matter And Foulant Characteristics In Membrane Bio-Reactor', Bioresource Technology, vol. 113, pp. 154-160.View/Download from: UTS OPUS or Publisher's site
In this study, the influence of organic loading rate (OLR) on the performance of a membrane bio-reactor (MBR) was investigated. The MBR was operated with 6 different OLRs between 0.5 and 3.0 kg COD/m3 d. The hydrodynamic parameters of the MBR were kept constant. The hydraulic retention time and sludge retention time were kept at 8 h and 40 d respectively. From the experimental investigation, it was found that the removal efficiency of DOC, COD and NH4-N decreased when OLRs were increased from 0.5 to 3.0 kg COD/m3 d. Higher OLRs of 2.75-3.0 kg COD/m3 d resulted in a higher transmembrane pressure development. The fractionation of organic matters showed more hydrophilic substances with higher OLRs. A detailed organic matter characterization of membrane foulant, soluble microbial product and extracellular polymeric substances showed that bio-polymers type substances together with humic acid and lower molecular neutral and acids were responsible for membrane fouling.
Mohammed Abdul, J, Kumar, MR, Vigneswaran, S & Kandasamy, JK 2012, 'Removal Of Metsulfuron Methyl By Fenton Reagent', Journal of Industrial and Engineering Chemistry, vol. 18, no. 1, pp. 137-144.View/Download from: UTS OPUS or Publisher's site
The removal of metsulfuron methyl (MeS)âa sulfonyl urea herbicide from contaminated water was investigated by advanced oxidation process (AOP) using Fenton method. The optimum dose of Fenton reagent (Fe2+/H2O2) was 10 mg/L Fe2+ and 60 mg/L H2O2 for an initial MeS concentration ([MeS]0) range of 0â80 mg/L. The Fenton process was effective under pH 3. The degradation efficiency of MeS decreased by more than 70% at pH > 3 (pH 4.5 and 7). The initial Fe2+ concentration ([Fe2+]0) in the Fenton reagent affected the degradation efficiency, rate and kinetics. The degradation of MeS at optimum dose of Fenton reagent was more than 95% for [MeS] 0 of 0â40 mg/L and the degradation time was less than 30 min. The determination of residual MeS concentration after Fenton oxidation by UV spectrophotometry was affected by the interferences from Fenton reagent. The estimation of residual MeS concentration after Fenton oxidation by high pressure/performance liquid chromatograph (HPLC) was interference free and represented the actual concentration of MeS and does not include the by-products of Fenton oxidation. The degradation kinetics of MeS was modelled by second order reactions involving 8 rate constants. The two reaction constants directly involving MeS were fitted using the experimental data and the remaining constants were selected from previously reported values. The model fit for MeS and the subsequent prediction of H2O2 were found to be within experimental error tolerances.
Pradhan, M, Vigneswaran, S, Kandasamy, JK & Ben Aim, R 2012, 'Combined effect of air and mechanical scouring of membranes for fouling reduction in submerged membrane reactor', Desalination, vol. 288, pp. 58-65.View/Download from: UTS OPUS or Publisher's site
This study investigated the combined effect of air flow and use of granular support medium in suspension in a submerged membrane reactor to reduce membrane fouling. Lower membrane fouling and a slower rise in transmembrane pressure (TMP) were noticed when a higher air flow rate was used for membrane scouring. Further fouling reduction was achieved by adding a granular medium in the reactor. The results showed that in the absence of the granular medium, when air flow was tripled (from 600 to 1800 L/h/m2), the TMP development was decreased by 60%. TMP further dropped to 85% with the addition of granular medium (for the same air flow rate). The doubling of the air flow rate (from 600 to 1200 L/h/m2), without granular medium, led to a 32% reduction in TMP development at 10 L/m2.h. The same result was obtained at a lower air flow rate of 600 L/h/m2 with the granular medium. This result shows that the same reduction of TMP can be obtained by adding granular medium instead of doubling air flow rate. Therefore adding granular medium in the suspension (mechanical scouring) with air flow (air scouring) could be a sustainable alternative to applying high air flow in submerged membrane systems.
Shim, WG, Mohammed Abdul, J, Mohammed, TM, Vigneswaran, S, Ngo, H & Kandasamy, JK 2012, 'Biofilter In Leachate Treatment Processes', Desalination and Water Treatment, vol. 41, no. 1-3, pp. 249-257.View/Download from: UTS OPUS or Publisher's site
Landfill leachate is produced when rainwater infiltrates into the landfill and permeates through the decomposing waste within the landfill leaching out with it contaminants and pollutants. Untreated leachates can permeate ground water or mix with surface
Mohammed Abdul, J, Colville, AE, Lim, RP, Vigneswaran, S & Kandasamy, JK 2012, 'Use of duckweed (Lemna disperma) to assess the phytotoxicity of the products of Fenton oxidation of metsulfuron methyl', Ecotoxicology And Environmental Safety, vol. 83, pp. 89-95.View/Download from: UTS OPUS or Publisher's site
Because of pressure on water supplies world-wide, there is increasing interest in methods of remediating contaminated ground waters. However, with some remediation processes, the breakdown products are more toxic than the original contaminant. Organic matter and salinity may also influence degradation efficiency. This study tested the efficiency of Fenton oxidation in degrading the sulfonylurea herbicide metsulfuron methyl (MeS), and tested the reaction products for phytotoxicity with the Lemna (duckweed) bioassay. The efficiency of degradation by Fentonâs reagent (Fe2Ã¾ Â¼0.09 mM; H2O2Â¼1.76mM, 4 h) decreased with increasing initial MeS concentration, from 98% with 5 mg/L MeS, to 63% with 70 mg/L MeS. Addition of NaCl (10 mM) and organic matter (humic acid at 0.2 and 2.0 mg C/L as Total Organic Carbon) reduced the efficiency of degradation at low initial MeS concentrations (5 and 10mg/L), but had no effect at high concentrations. The residual Fentonâs reagent after Fentonâs oxidation was toxic to Lemna. After removal of residual iron and H2O2, the measured toxicity to Lemna in the treated samples could be explained by the concentrations of MeS as measured by HPLC/UV detection, so there was no evidence of additional toxicity or amelioration due to the by-products or formulation materials.
Nur, T, Johir, MAH, Loganathan, P, Vigneswaran, S & Kandasamy, J 2012, 'Effectiveness of purolite A500PS and A520E ion exchange resins on the removal of nitrate and phosphate from synthetic water', Desalination and Water Treatment, vol. 47, no. 1-3, pp. 50-58.View/Download from: UTS OPUS or Publisher's site
Water pollution due to the excessive presence of nutrients (nitrogen and phosphorus) is a serious environmental worldwide problem, because both species are implicated in the eutrophication of receiving surface waters and elevated nitrate concentration in drinking water can be toxic to infants. The removal efficiencies of nitrate and phosphate from water spiked with different ratios and concentrations of these nutrients by two ion-exchange resins (Purolite A500PS and Purolite A520E) were studied in batch kinetics and equilibrium adsorption experiments. Both purolites were found to be selective towards nitrate removal at all ratios of nitrate to phosphate in solution. Purolite A520E showed higher (<85%) removal efficiency of nitrate than Purolite A500PS (about 65%) from a solution containing 20mgN/L as nitrate and 10mgP/L as phosphate at a resin dose of 1.5 g/L. However, Purolite A500PS showed higher (65%) removal of phosphate than Purolite A520E (48%). Langmuir and Freundlich isotherm models fitted well for the adsorption of nitrate on Purolite A520E (R2 = 0.950.96). However, the adsorption of nitrate on Purolite A500PS can be explained satisfactorily only by Freundlich model (R2 = 0.98). The adsorption of phosphate on the resins fitted well to Freundlich model (R2 = 0.90) for Purolite A500PS as well as for Purolite A520E (R2 = 0.90). The adsorption of phosphate and nitrate on both ion-exchange resins was much better described by pseudo-second-order kinetic model (R2P0.99) than by pseudo-first-order kinetic model (R2 = 0.250.94).
El Saliby, I, Okour, Y, Shon, H, Kandasamy, JK, Lee, WE & Kim, J 2012, 'TiO2 nanoparticles and nanofibres from TiCl4 flocculated sludge: Characterisation and photocatalytic activity', Journal of Industrial and Engineering Chemistry, vol. 18, no. 3, pp. 1033-1038.View/Download from: UTS OPUS or Publisher's site
In this study, dye and secondary effluent wastewaters were used to generate a non-hazardous sludge. Anatase TiO2 nanoparticles have been successfully synthesised from the calcination of the TiCl4 flocculated sludge. A conventional hydrothermal method was adopted to produce anatase nanofibres (calcined at 600 8C) from TiO2 nanoparticles. X-ray diffraction, scanning electron microscopy and transmission electron microscopy investigations showed the highly crystalline nanoparticles and nanofibres after calcination. The size of nanofibres was related to the size of their nanoparticles precursors. Nanoparticles had larger surface area than nanofibres, lower pore volume and bigger pore diameter. Energy dispersive X-ray analysis revealed that impurities can be successfully removed by a subsequent hydrothermal/acid wash of nanoparticles. Nanoparticles had better overall photocatalytic activity for the degradation of organics in synthetic wastewater compared to nanofibres. On the other hand, nanofibres had a better adsorption capacity.
Phuntsho, S, Shon, H, Majeed, T, El Saliby, I, Vigneswaran, S, Kandasamy, JK, Hong, S & Lee, S 2012, 'Blended Fertilizers as Draw Solutions for Fertilizer-Drawn Forward Osmosis Desalination', Environmental Science & Technology, vol. 46, pp. 4567-4575.View/Download from: UTS OPUS or Publisher's site
In fertilizer-drawn forward osmosis (FDFO) desalination, the final nutrient concentration (nitrogen, phosphorus, potassium (NPK)) in the product water is essential for direct fertigation and to avoid over fertilization. Our study with 11 selected fertilizers indicate that blending of two or more single fertilizers as draw solution (DS) can achieve significantly lower nutrient concentration in the FDFO product water rather than using single fertilizer alone. For example, blending KCl and NH4H2PO4 as DS can result in 0.61/1.35/1.70 g/L of N/P/K, which is comparatively lower than using them individually as DS. The nutrient composition and concentration in the final FDFO product water can also be adjusted by selecting low nutrient fertilizers containing complementary nutrients and in different ratios to produce prescription mixtures. However, blending fertilizers generally resulted in slightly reduced bulk osmotic pressure and water flux in comparison to the sum of the osmotic pressures and water fluxes of the two individual DSs as used alone. The performance ratio or PR (ratio of actual water flux to theoretical water flux) of blended fertilizer DS was observed to be between the PR of the two fertilizer solutions tested individually. In some cases, such as urea, blending also resulted in significant reduction in N nutrient loss by reverse diffusion in presence of other fertilizer species.
Loganathan, L, Vigneswaran, S, Kandasamy, JK & Naidu, R 2012, 'Cadmium Sorption And Desorption In Soils: A Review', Critical Reviews in Environmental Science and Technology, vol. 42, no. 5, pp. 489-533.View/Download from: UTS OPUS or Publisher's site
Cadmium (Cd) is an environmental pollutant that can be readily taken up by plants and may enter the food chain, causing risk to human health. It can also affect soil quality and, if easily leached, has the potential to pollute surface and ground waters. Sorption and desorption are critical processes controlling the phytoavailability and mobility of Cd in soils. The authors present the present knowledge on the mechanisms and hysteresis of Cd sorption and desorption in soils and factors such as pH, ionic strength, index cation, other heavy metal cations, inorganic anions, organic ligands, Cd loading rate, and the type and amounts of organic matter and inorganic colloids influencing these processes. The methods used to determine the nature and magnitude of Cd sorption and desorption are also critically reviewed.
Mohammed, TM, Aryal, R, Vigneswaran, S, Loganathan, L, Kandasamy, JK & Naidu, R 2012, 'Removal of heavy metals in stormwater by hydrous ferric oxide', Water Management, vol. 165, no. WM3, pp. 171-178.View/Download from: UTS OPUS or Publisher's site
Stormwater runoff from urban and industrial areas contains several types of heavy metals that have negative ecological impacts on receiving waters, and therefore methods need to be developed to remove these pollutants. Combined removal of a mixture of heavy metal cations (Cu2Ã¾, Zn2Ã¾, Cd2Ã¾, and Ni2Ã¾) and an oxy anion (selenate, SeO42) from an artificially prepared stormwater was investigated by sorption of these heavy metals on hydrous ferric oxide (HFO) in a column experiment under intermittent runoff (wetting and drying) condition, as occurs between rainfall events in the field. The heavy metal removal behaviour varied between ions as well as with time. In each continuous column run (8 h) the amount of ions removed progressively decreased with time and reached a constant level at approximately 4â6 h. However, stopping the runoff for 40 h and starting the next runoff after this period removed a large quantity of heavy metals in the first few hours of this run. The intermittent runoff for seven runs showed that HFO has a high capacity to remove copper and zinc, which were present in higher concentrations in the stormwater than cadmium, nickel and selenium.
Mohammed, TM, Loganathan, L, Kinsela, A, Vigneswaran, S & Kandasamy, JK 2012, 'Enrichment, Inter-Relationship, And Fractionation Of Heavy Metals In Road-Deposited Sediments Of Sydney, Australia', Australian Journal of Soil Research, vol. 50, no. 3, pp. 229-238.View/Download from: UTS OPUS or Publisher's site
Urban road-deposited sediments (RDS) are potential sources of heavy metal pollution of both terrestrial and aquatic environments. We determined the heavy metals enrichments, their possible sources, and potential bioavailability and mobility in RDS from n
Mohammed, TM, Vigneswaran, S, Loganathan, L, Kandasamy, JK & Aryal, R 2012, 'Removal of inorganic contaminants from simulated stormwater by three sorbents in columns under intermittent runoff condition', Separation Science and Technology, vol. 42, no. 14, pp. 2340-2347.View/Download from: UTS OPUS or Publisher's site
Combined removal of inorganic contaminants from a synthetic tormwater was investigated by their sorption on hydrous ferric oxide (HFO) (5%), HFO + Ca(OH)2(6%), and HFO + Ca(OH)2 + MnO2 (7%) in columns containing 93-95% anthracite, conducted under seven intermittent runoffs, each of 8 h duration with a 40 h (drying) period between them. At the initial period when Ca(OH)2 produced elevated pHs, the HFO column removed less metals but more Se than the HFO + Ca(OH)2 columns. With increased time when the pH effect of Ca(OH)2 became insignificant, the MnO2 in the column increased the removal of all contaminants. The removal efficiencies (%) at the flow rate of 0.75 m/h for Cd, Cu, Ni, Zn by the HFO + Ca(OH)2 + MnO2 column were 88-100%, and Se by the HFO column were 92-94% for the 1st and 3rd runs. The corresponding values for the 5th and 7th runs were 51-88% and 82-88%, respectively.
Chanan, AP, Ghetti, I & Kandasamy, JK 2011, 'Challenges of managing coastal areas through climate change', Institution of Civil Engineers. Proceedings. Municipal Engineer, vol. 164, no. 2, pp. 83-88.View/Download from: Publisher's site
In Australia the strongest natural fluctuation of climate from year to year is the El NiÃ±o southern oscillation. La NiÃ±a years are associated with an increased probability of wetter and cooler conditions, whereas El NiÃ±o years are drier and hotter then normal. For an urbanised coastal council such as Kogarah there are a number of impacts associated with climate change. For instance, the risk of flooding may be increased due to more intense rainfalls coupled with rising sea levels. Coastal councils may also experience increased coastal flooding and erosion due to increased storm surges and rising sea levels. Water restrictions are already in place due to severe droughts, and it is predicted that councils will have limited water supply available for the irrigation needed to provide parks and well-maintained sporting facilities for the community. Given that the science of climate change is not an exact science there are obvious technical and sociopolitical challenges to be addressed. This paper shares Kogarah Council's experiences in dealing with these challenges and provides a snapshot of programmes currently being implemented in response to climate change. By investing in proactive measure to reduce risk and vulnerability it is possible to build resilience to climate change.
Ho, D, Vigneswaran, S, Ngo, H, Shon, H, Kandasamy, JK, Chang, Y & Chang, J 2011, 'Photocatalysis of Trimethoprim (TRI) in Water', Sustainable Environment Research, vol. 21, no. 3, pp. 149-154.View/Download from: UTS OPUS
The advantage of the use of photocatalysts to treat persistent organic pollutants (POP) was demonstrated with the decomposition of trimethoprim (TRI), an antibiotic most frequently detected in municipal wastewaters and surface waters. In this study, the oxidation process by UV/TiO2 was employed as an alternative to advanced oxidation process (AOP) to remove residual antibiotics from water. High concentrations of TRI were used to study the efficiency of photocatalysis. Both batch and continuous photoreactors were used. The decomposition of TRI by TiO2/UV photooxidation occurred gradually over time. On the other hand, with UV irradiation alone, the reduction of TRI mineralization was relatively small. The effect of light intensity showed there was no significant impact of UV light intensity on the degradation of TRI in the range of increasing intensities studied. The simulation using first-order kinetics provided a good fit with the experimental data. In the continuous system, the feed flow rate was adjusted to maximize the percentage of mineralization of targeted compounds inside the photoreactor. A lower flow rate, i.e., higher detention time, achieved higher percentage of TRI mineralization. The results indicated that TiO2/UV irradiation was effective in removing TRI.
Kus, BG, Kandasamy, JK, Vigneswaran, S & Shon, H 2011, 'Water Quality in Rainwater Tanks in Rural and Metropolitan Areas of New South Wales, Australia', Journal of Water Sustainability, vol. 1, no. 1, pp. 33-43.View/Download from: UTS OPUS
This paper compares the water quality of rainwater tanks throughout the Sydney metropolitan area to that in rural New South Wales, Australia. The water quality is compared against the Australian Guidelines for Water Recycling (AGWR) to determine if the untreated rainwater from both areas can be considered suitable for non-potable water supply without filtration. Additionally this paper reports on a set of experiments where rainwater collected from a typical domestic roof in Sydney, New South Wales, Australia was treated by a pre-treatment of granular activated carbon (GAC) adsorption filter followed by micro-filtration. The GAC column removed the pollutants through an adsorption mechanism. GAC is a macroporous solid with a very large surface area providing many sites for adsorption and it is this property that makes it an efficient adsorbent. The parameters analysed were ammonia, anions and cations, heavy metals, nitrate and nitrite, pH, total hardness, total organic carbon, total suspended solids and turbidity. The results indicate that before treatment, the rainwater already complied to many of the parameters specified in the AGWR, certain pollutants have the potential at times to exceed the AGWR. The water quality was within the AGWR limits after the treatment. The micro- filtration flux values demonstrate that rainwater was able to be filtered through the membranes under low gravitational heads that are typically available in a rainwater tank while still producing sufficient membrane flux and pollutant removal rates.
Kus, BG, Kandasamy, JK, Vigneswaran, S, Shon, H & Areerachakul, N 2011, 'Water quality of membrane filtered rainwater', Desalination and Water Treatment, vol. 32, pp. 208-213.View/Download from: UTS OPUS or Publisher's site
Although most Australians receive their domestic supply from reticulated mains or town water, there are vast areas with very low population densities and few reticulated supplies. In many of these areas rainwater collected in tanks is the primary source of drinking water. Heavy metals are a concern as their concentration in rainwater tanks was found to exceed recommended levels suitable for human consumption. This paper reports on experimental investigations where rainwater collected from a typical domestic roof in Sydney, Australia was treated in two stages of filtration including granular activated carbon (GAC) as a pre-treatment adsorption filter media and a metallic membrane from Steri-flow Filtration Systems Pty. Ltd. The quality of the treated rainwater was compared against the drinking water standards to determine its suitability as a supplement for potable water supply. The pollutants analysed were heavy metals, total coliform and faecal coliforms, total organic carbon, total suspended solids and turbidity. The results indicate that before treatment, the rainwater already complied with many of the parameters specified in drinking water standards. The metallic membrane performed well in removing suspended particles and heavy metals from the rainwater. The performance of the metallic membrane is greatly improved by the use of pre-treatment such as GAC which was used in this experiment.
Shon, H, Vigneswaran, S, Kandasamy, JK, Kim, J & Kim, J 2011, 'Advanced Characterization Techniques Of Organic Matter In Aqueous Solutions', Journal of the Korean Industrial and Engineering Chemistry, vol. 22, no. 1, pp. 1-14.View/Download from: UTS OPUS
Water is the most precious resource to human being, but it is polluted by different organic compounds. Organic matter (OM) in aqeous solutions is one of the important parameters of concern for human and environmental impact, and thus, it is essential to
Singh, G, Kandasamy, JK, Shon, H & Cho, J 2011, 'Measuring treatment effectiveness of urban wetland using hybrid water quality - Artificial neural network (ANN) model', Desalination and Water Treatment, vol. 32, pp. 284-290.View/Download from: UTS OPUS or Publisher's site
Constructed wetlands are now commonly used as tertiary treatment for urban stormwater. The wetlands have primary advantage over other forms of treatment as they remove dissolved organics and heavy metals in conjunction with other pollutants. The effectiveness of a wetland is a primary concern for validating its compliance with design objectives and regulatory requirements. The treatment in a wetland is however complex and is dependent on input pollutants, hydraulics, physicochemical balance and biota within the wetland. Several models are available for wetlands but have limitations in simulating the physico-chemical and biological processes within the wetland. The aim of this paper is to introduce a hybrid modelling approach that involves both a deterministic model and artificial neural network (ANN) for testing the effectiveness of a constructed wetland at Olympic Park, Homebush, Sydney, Australia. This novel approach allows a combination of calibrated water quality and neural based models to predict the water quality from the wetland. The models were calibrated and validated using water quality monitoring data measured for eight months in both influent and effluent streams of the wetland. The calibrated hybrid models were then tested for treatment effectiveness for range of wet, dry and median flows conditions within the catchments. A water quality index was developed and used to quantify the effectiveness of the wetland.
Aryal, R, Vigneswaran, S & Kandasamy, JK 2011, 'Application of Ultraviolet (UV) Spectrophotometry in the Assessment of Membrane Bioreactor Performance for Monitoring Water and Wastewater Treatment', Applied Spectrocopy, vol. 65, no. 2, pp. 227-232.View/Download from: UTS OPUS or Publisher's site
Ultraviolet (UV) spectroscopy has been widely used in monitoring water and wastewater treatment. In this study UV spectroscopy was used to investigate fouling development on the membrane surface of membrane bioreactors. The chemistry of mixed liquor present in the membrane bioreactor and the foulant deposited on the membrane surface was compared by analyzing the UV spectra. The mixed liquor showed different spectra than did the foulant. The foulant spectra showed a shift in absorbance peaks with operation time. The particle size distribution (<450 nm) was also examined to explain the UV fingerprints.
Contemporary water management challenges around Australia highlight water engineers' inability to understand the community's needs. Developing new technologies is not enough. Implementation of these technologies can only take place if the engineers under
Chanan, AP, Vigneswaran, S, Kandasamy, JK & Simmons, B 2011, 'Lessons for a viable water recycling industry', Institution of Civil Engineers. Proceedings. Water Management, vol. 164, no. 5, pp. 213-219.View/Download from: UTS OPUS or Publisher's site
The platform on which the labour government came to power in Australia in November 2007 included a policy of setting a national wastewater recycling target of 30% by the year 2015. A similar target-based approach was followed by the solid waste recycling industry in Australia the policy of which focused on supply and did not adequately acknowledge the price competitiveness of the product and its demand. This paper highlights the lessons from the solid waste recycling industry and applies them to the water recycling sector. A sound water pricing regime that reflects the true costs of water and a competitive water industry is offered as a better policy alternative to setting recycling targets.
Johir, MH, Aryal, R, Vigneswaran, S, Kandasamy, JK & Grasmick, A 2011, 'Influence Of Supporting Media In Suspension On Membrane Fouling Reduction In Submerged Membrane Bioreactor (Smbr)', Journal Of Membrane Science, vol. 374, no. 1-2, pp. 121-128.View/Download from: UTS OPUS or Publisher's site
In this study, the SMBR was compared in terms of membrane fouling with and without the addition of suspended medium in the membrane reactor. The effectiveness of medium in suspension in submerged membrane bioreactor (SMBR) was evaluated at different filt
Johir, MH, George, J, Vigneswaran, S, Kandasamy, JK & Grasmick, A 2011, 'Removal and recovery of nutrients by ion exchange from high rate membrane bio-reactor (MBR) effluent', Desalination, vol. 275, no. 2, pp. 197-202.View/Download from: UTS OPUS or Publisher's site
In this study a membrane bioreactor (MBR) with ion-exchange as post-treatment was investigated for organic removal and nutrient recovery. The MBR was operated at a short HRT of 4 h in order to mainly remove organic carbon. This was followed by an ion-exchange process to remove and later recover the nitrogen and phosphorus from the MBR effluent. The increase in membrane resistance was reduced by 90% (from 0.061 to 0.006 m-1d-1) when the air scouring rate was increased from 0.5 to 1.5 m3/m2 membrane area h. The organic removal rate in terms of DOC was 85â90%. The bio-polymer in the molecular weight range of 24,500 Da was retained by the membrane of the MBR while humic type substances and lower molecular organic matter (molecular weight of 360â60 Da) were not effectively removed by the membrane. The ion-exchange process effectively removed the nutrients from the effluent of the MBR. The retention of PO4 3â and NO3 â by the two ion-exchange columns in series was 85% and 95% respectively. Over 95â98% phosphate and nitrate recovery was obtained during regeneration of columns with 1% NaCl of 20 bed volumes. This integrated process can remove pollutants and at the same time recover nutrients and thus open a new source for nitrogen and phosphorous.
Khorshed, C, Vigneswaran, S, Kandasamy, JK, Aryal, R & Dharmapalan, D 2011, 'Assessment of water treatment processes: Detailed organic matter characterisation and membrane fouling indices at the Loddon Water Treatment Plant, Victoria, Australia', Water Science and Technology, vol. 11, no. 3, pp. 274-280.View/Download from: UTS OPUS or Publisher's site
Mohammed, TM, Vigneswaran, S & Kandasamy, JK 2011, 'Biofiltration as pre-treatment to water harvesting and recycling', Water Science and Technology, vol. 63, no. 10, pp. 2097-2105.View/Download from: UTS OPUS or Publisher's site
This paper presents the results of the long term biofilter experiments conducted with raw stormwater collected from a canal at Carlton, in Sydney. Anthracite and granular activated carbon (GAC) were used as a single filter media in biofilter columns. Media heights of 75 and 40 cm were used. The filter columns were operated at filtration velocities of 0.12 and 0.25 m/h. The removal efficiency for turbidity and DOC for the GAC filter media were found to be 75% and almost 100% respectively. The removal efficiency for the anthracite filter was much lower. Molecular weight distribution analysis showed an almost similar trend to the DOC removal. Compared with anthracite filter media, the GAC biofilter removed a much larger range of organic compounds present in the stormwater. The GAC biofilter removes organic matter earlier as compared to anthracite. Based on a limited sample of stormwater, the removal efficiency for phosphorus was upto 74% and that of nitrogen was up to 30%. In general GAC filter shows higher heavy metal removal efficiency than anthracite. The removal of zinc, iron, lead and nickel were good. However the concentration of heavy metal in the raw surface water sample was low.
Nguyen, V, Zhang, R, Vigneswaran, S, Ngo, H, Kandasamy, JK & Mathes, P 2011, 'Removal of organic matter from effluents by Magnetic Ion Exchange (MIEX)', Desalination, vol. 276, no. 1-3, pp. 96-102.View/Download from: UTS OPUS or Publisher's site
Magnetic Ion Exchange Resin (MIEXÂ®) is effective in removing the majority of organic carbon from biologically treated wastewater. It removed 77% of dissolved organic carbon (DOC) from synthetic wastewater when operated in batch mode using a MIEXÂ® concentration of 10 mL/L. A pseudo secondorder reaction rate model namely the Ho model was used for the kinetic study and it was found that it provided a realistic description of the adsorption kinetics of DOC. A fluidised bed MIEXÂ® contactor effectively removed organic matter from synthetic biologically treated sewage effluent with more than 60% DOC removal even after 172 bed volumes. The regenerated MIEXÂ® resin did not display any significant reduction in its ability to remove organic matter.
Pradhan, M, Aryal, R, Vigneswaran, S & Kandasamy, JK 2011, 'Application of air flow for mitigation of particle deposition in submerged membrane microfiltration', Desalination and Water Treatment, vol. 32, pp. 201-207.View/Download from: UTS OPUS or Publisher's site
This study investigates the effect of microfiltration operating conditions on membrane fouling of colloidal particles of kaolin clay. Experiments were conducted with a flat sheet membrane submerged in a suspension prepared from kaolin clay powder of size varying from 0.1 to 4 mm (Sigma) with a mean particle size 2.10 mm. The particle size distribution of clay was unimodal and the concentration of kaolin clay was similar to the biomass concentration in a membrane bioreactor (10 g/L). The effects of scouring and permeate flux rates were studied in terms of the membrane fouling rate. A linear relationship between the transmembrane pressure (TMP) and particle deposition was established for different air flow rates and permeate flow rates. Air scouring was more effective at a low permeate flux. There was only a minor change in the mean particle size of deposited colloidal particles on the membrane at a given flux under varying air flows and at the beginning all had a similar rise in TMP. However, at the later stages as particles accumulated on the membrane surface there was a significant rise in TMP. 15 LMH flux was observed as critical flux beyond which a rise in the permeate flux showed a sharp rise in the TMP which varied with air flow rates and particle deposition. The sharp TMP rise that occurred during the initial few hours of operation indicated that air flow for fouling mitigation strategies should target this period to optimise the membrane process. The study showed that air flow and flux rates are the two major governing factors for particle deposition on the membrane surface.
El Saliby, I, Shon, H, Kandasamy, JK & Kim, J 2011, 'Synthesis, characterisation and separation of photoreactive Hydrogen-titanate nanofibrous channel', Separation and Purification Technology, vol. 77, no. 2, pp. 202-207.View/Download from: UTS OPUS or Publisher's site
Australia is the world's largest wool producing country, accounting for about 25â30% of world production. As a biotemplate, we explored the possibility of using wool to produce micro-channel of Hydrogentitanate nanofibres through morphology transcription of wool microfibres. Hydrothermal method was adopted to synthesise titanate nanofibres. A facile method of impregnation followed by incineration at 600 â¦C was utilised to prepare the nanofibrous channel. Anatase undoped nanofibrous (average nanofibre diameter = 44 nm) channel of around 50min length and an average diameter of 9.5mwere obtained. The photocatalytic activity of nanofibrous channel was monitored under UV irradiation for the decomposition of humic acid in aqueous solution using an aerobic batch reactor system. The photodegradation results showed that UV254 absorbing moeities and DOC were respectively reduced by 82% and 66% after 3 h of photoreaction at 1 g/L catalyst load. The novel nanofibrous channel could be easily separated from the aqueous suspension by sedimentation after the end of the photocatalytic reaction.
Aryal, R, Vigneswaran, S, Loganathan, L, Kandasamy, JK & Mohammed, TM 2011, 'Hydrous iron oxide for removal of inorganic contaminants in simulated stormwater: A batch sorption kinetics study', Korean Journal of Chemical Engineering, vol. 28, no. 8, pp. 1706-1712.View/Download from: UTS OPUS or Publisher's site
Urban stormwater runoff, which consists of inorganic and organic contaminants, is a major source of pollutants to receiving waters and therefore they need to be removed. Simultaneous removal of contaminants, Cd2+, Cu2+, Ni2+, Zn2+ (heavy metal cations), and SeO4 2â (oxyanion) from a simulated stormwater by a hydrous ferric oxide (HFO) was studied in batch and column sorption experiments. In the batch experiment the rate of sorption of the ions was rapid at the beginning and reached equilibrium in approximately 300 min. The amounts of ions sorbed were proportionate to the respective initial concentration of the ions added to the HFO. Cluster analysis showed that all heavy metals had similar sorption behavior, whereas Se had a distinctly different sorption process. Of the three different kinetic models tested the pseudo-first order kinetic model fitted the data the best. The column experimental results beyond 180 min were consistent with those of the batch experiment that the removal efficiencies of the ions were in proportion to the ion concentration in the feed. Below 180 min, Cu appeared to be preferentially removed than Zn.
Chanan, AP, Vigneswaran, S, Kandasamy, JK & Shon, H 2010, 'Chemical-assisted physico-biological water mining system', Institution of Civil Engineers. Proceedings. Water Management, vol. 163, no. 9, pp. 469-474.View/Download from: UTS OPUS or Publisher's site
Water mining is the process of extracting valuable water from a sewerage network by treating raw sewage to high standards. A range of commercially viable water mining treatment technologies are now available to treat sewage to specified water quality targets. Most of these technologies have minimal plant footprint requirements, making them suitable for decentralised operations. This paper discusses a hybrid water mining system that includes chemically assisted fine solids separation followed by a biological treatment process. Results from the first proof testing of this water mining system in Sydney, Australia are presented. The results confirm the suitability of the hybrid system for producing high-quality water for non-potable reuse.
Chinu, KJ, Johir, MH, Vigneswaran, S, Shon, H & Kandasamy, JK 2010, 'Assessment of pretreatment to microfiltration for desalination in terms of fouling index and molecular weight distribution', Desalination, vol. 250, no. 2, pp. 644-647.View/Download from: UTS OPUS or Publisher's site
In this study, different processes such as flocculation with ferric chloride (FeCl3) and deep bed filtration (sand filtration and dual media filtration) as a pre-treatment to microfiltration (MF) were used for seawater desalination. The performance of these pre-treatments was determined in terms of silt density index (SDI) and modified fouling index (MFI) and flux decline in MF. Flux decline of MF with seawater was 45% without any pre-treatment, 42% after pre-treatment of FeCl3 flocculation, 24% after pre-treatment of sand filtration with in-line coagulation and 22% after pre-treatment of dual media filtration (sand and anthracite), respectively. MFI and SDI also indicated that deep bed filtration with in-line flocculation was better pretreatment than flocculation alone. Detailed molecular weight distribution (MWD) of seawater organic matter was examined after different pretreatments. MWD of the initial seawater mainly ranged from 1510 Da to 130 Da. Deep bed filtration with in-line flocculation removed relatively large molecular weight of organic matter (1510â1180 Da), while the small molecular weights (less than 530 Da) were not removed.
Chinu, KJ, Vigneswaran, S, Erdei, L, Shon, H, Kandasamy, JK & Ngo, H 2010, 'Comparison of fouling indices in assessing pre-treatment for seawater reverse osmosis', Desalination and Water Treatment, vol. 18, no. 1-5, pp. 187-191.View/Download from: UTS OPUS or Publisher's site
In this study, different processes such as flocculation with ferric chloride (FeCl3) and deep bed filtration (sand filtration and dual media filtration) as a pre-treatment were used for seawater desalination. The performance of these pre-treatments was determined in terms of silt density index (SDI) and modified fouling index by using microfilter (MF-MFI), ultrafilter (UF-MFI), and nanofilter (NF-MFI) membrane. MFI and SDI indicated that deep bed filtration with in-line flocculation was better pre-treatment than flocculation alone as colloidal particles are removed after this pretreatment. UF-MFI and NF-MFI indicated that these pretreatment cannot remove dissolved organic matter as the fouling reduction was smaller. Detailed molecular weight distribution (MWD) of seawater organic matter was examined after different pretreatments. MWD of the initial seawater mainly ranged from 1510 Da to 130 Da. Deep bed filtration with in-line flocculation removed relatively large molecular weight of organic matter (1510â1180 Da), while the small molecular weights (less than 530 Da) were not removed.
Kus, BG, Kandasamy, JK, Vigneswaran, S & Shon, H 2010, 'Analysis of first flush to improve the water quality in rainwater tanks', Water Science and Technology, vol. 61, no. 2, pp. 421-428.View/Download from: UTS OPUS or Publisher's site
Although most Australians receive their domestic supply from reticulated mains or town water, there are vast areas with very low population densities and few reticulated supplies. In many of these areas rainwater collected in tanks is the primary source of drinking water. Heavy metals have recently become a concern as their concentration in rain water tanks was found to exceed recommended levels suitable for human consumption. Rainwater storage tanks also accumulate contaminants and sediments that settle to the bottom. Although not widely acknowledged, small amounts of contaminants such as lead found in rain water (used as drinking water) may have a cumulative and poisonous effect on human health over a life time. This is true for certain factors that underlie many of the chronic illnesses that are becoming increasingly common in contemporary society. The paper reports on a study which is part of a project that aims to develop a cost effective in-line filtration system to improve water quality in rainwater tanks. To enable this, the characteristics of rainwater need to be known. One component of this characterization is to observe the effects of the first flush on a rainwater tank. Samples of the roof runoff collected from an urban residential roof located in the Sydney Metropolitan Area in the initial first few millimetres of rain were analysed. The results show that bypassing the first 2mm of rainfall gives water with most water quality parameters compliant with the Australian Drinking Water Guidelines (ADWG) standards. The parameters that did not comply were lead and turbidity, which required bypassing approximately the first 5mm of rainfall to meet ADWG standards. Molecular weight distribution (MWD) analysis showed that the concentration of rainwater organic matter (RWOM) decreased with increasing amount of roof runoff.
Kus, BG, Kandasamy, JK, Vigneswaran, S & Shon, H 2010, 'Water quality characterisation of rainwater in tanks at different times and locations', Water Science and Technology, vol. 61, no. 2, pp. 429-439.View/Download from: UTS OPUS or Publisher's site
Rainwater collected from ten domestic roofs in Sydney and from one in Wollongong, a town south of Sydney, Australia was analysed to determine the water quality and to compare against the Australian Drinking Water Guidelines (ADWG) to determine its suitability as a potable water supply. The pollutants analysed were 13 heavy metals, 8 salts & minerals, pH, ammonia, orthophosphate, conductivity, water hardness, turbidity, total suspended solids, Total dissolved salts & Bicarbonate. The results indicate that the rainwater tested complied to most of the parameters specified in the ADWG. Molecular weight distribution of organic matter from one of the domestic rainwater tanks was analysed in terms of the effects of aging and roof contact. Molecular weight distribution of organic matter in rainwater showed prominent peaks at 37,500 daltons may be due to biopolymers, 850 Da to humic substances, 500 Da to building blocks, 220 Da to low MW acids, and less than 220 Da to amphiphilics. The findings also indicate that the first flush volumes that by-passed the tank can have a significant influence on the water quality in the rainwater tank.
Lee, J, Johir, MH, Chinu, KJ, Shon, H, Vigneswaran, S, Kandasamy, JK, Kim, CW & Shaw, K 2010, 'Novel pre-treatment method for seawater reverse osmosis: Fibre media filtration', Desalination, vol. 250, no. 2, pp. 557-561.View/Download from: UTS OPUS or Publisher's site
A high rate fibre filter was used as a pre-treatment to seawater reverse osmosis (SWRO) to reduce membrane fouling. Seawater was drawn from Chowder Bay where the Sydney Institute of Marine Science, Australia is located. A lab-scale fibre filter with a height of 1000 mm and a diameter of 30 mm was used in conjunction with in-line coagulation. The effect of operating the fibre filter with different packing densities (105, 115 kg/m3) and filtration velocities (40, 60 m/h) was investigated in terms of silt density index (SDI10), modified fouling index (MFI), pressure drop (ÎP), turbidity and molecular weight distribution (MWD). The use of in-line coagulation improved the performance of fibre filter as measured by the MFI and SDI. Regardless of filtration velocity and packing density the MFI and SDI10 values remained low as did the turbidity until the end of the filtration run. The MWD analysis showed the removal efficiencies of organic materials like biopolymers, fulvic acids, low MW acids for even experiments with the highest filtration velocity (60 m/h) and lowest packing density (105 kg/m3). This pre-treatment has a small foot print as it has the capacity of operating at a very high filtration velocity
Shon, H, Phuntsho, S, Vigneswaran, S, Kandasamy, JK, Kim, JB, Park, HJ & Kim, IS 2010, 'PVDF-TiO2 Coated microfiltration membranes: preparation and characterization', Membrane Water Treatment, vol. 1, no. 3, pp. 193-206.View/Download from: UTS OPUS or Publisher's site
Organic fouling and biofouling pose a significant challenge to the membrane filtration process. Photocatalysis-membrane bybrid system is a novel idea for reducing these membranes fouling however, when TiO2 photocatalyst nanoparticles are used in suspension, catalyst recovery is not only imposes an extra step on the process but also significantly contributes to increased membrane resistance and reduced permeate flux. In this study, TiO2 photocatalyst has been immobilized by coating on the microfiltration (MF) membrane surface to minimize organic and microbial fouling. Nano-sized TiO2 was first synthesized by a sol-gel method. The synthesized TiO2 was coated on a Poly Vinyl Difluoride (PVDF) membrane (MF) surface using spray coating and dip coating techniques to obtain hybrid functional composite membrane. The characteristics of the synthesized photocatalyst and a functional composite membrane were studied using numerous instruments in terms of physical, chemical and electrical properties. In comparison to the clean PVDF membrane, the TiO2 coated MF membrane was found more effective in removing methylene blue (20%) and E-coli (99%).
Shon, H, Phuntsho, S, Vigneswaran, S, Kandasamy, JK, Nghiem, LD, Kim, G, Kim, JB & Kim, J 2010, 'Preparation of Titanium Dioxide Nanoparticles from Electrocoagulated Sludge using Sacrificial Titanium Electrodes', Environmental Science & Technology, vol. 44, no. 14, pp. 5553-5557.View/Download from: UTS OPUS or Publisher's site
A comprehensive investigation of electrocoagulation using sacrificial titanium (Ti) electrodes in wastewater was carried out. The effects of specific process variables, such as initial pH, mixing, current density, initial organic loading, and ionic/ electrolyte strength were first optimized to produce recyclable Ti-based sludge. The sludge was incinerated at 600Â°C to produce functional TiO2 photocatalyst. X-ray diffraction analysis revealed that TiO2 produced at optimum electrocoagulation conditions was mostly anatase structure. The specific surface area of the synthesized TiO2 photocatalyst was higher than that of the commercially available and widely used Degussa P-25 TiO2. Furthermore, energy dispersive X-ray and X-ray photoelectron spectroscopy analyses showed that in additional to titanium and oxygen, this photocatalyst is also composed of carbon and phosphorus. These elements were mainly doped as a substitute site for the oxygen atom. Transmission electron microscopy images exhibited sharply edged nanorods, round nanoparticles, and nanotubes with nonuniform shapes showing some structural defects. Photodecomposition of gaseous acetaldehyde by this photocatalyst was also conducted under UV and visible light irradiation to study the photocatalytic properties of the doped TiO2 photocatalyst. While no photocatalytic activity was observed under visible light irradiation, this doped TiO2 photocatalyst exhibited high photocatalytic activity under UV light.
Aryal, R, Vigneswaran, S & Kandasamy, JK 2010, 'Influence of buoyant media on particle layer dynamics in microfiltration membranes', Water Science & Technology: Water Supply, vol. 61, no. 7, pp. 1733-1738.View/Download from: UTS OPUS or Publisher's site
This study forms a part of the physical study of the membrane bioreactor in presence of buoyancy media. Kaolin clay suspension with buoyancy media (anthracite) was used as a suspension and the particle layer development on membrane surface with evolution of time was studied. Presence of buoyancy media reduced the pressure development by almost two folds compared to in absence of the media. The particles deposition on membrane surface was size selective. The mean particle diameter (0.45mm) deposited on the membrane surface remained almost similar in presence of the media after 7 hrs run where as in its absence the mean diameter finer particles deposition occurred at the beginning followed by coarser particles.
Aryal, R, Vigneswaran, S, Kandasamy, JK & Naidu, R 2010, 'Urban stormwater quality and treatment', Korean Journal Of Chemical Engineering, vol. 27, no. 5, pp. 1343-1359.View/Download from: UTS OPUS or Publisher's site
Stormwater runoff from urban and suburban areas generates numerous pollutants. The areas include residential areas, parks, commercial areas, industrial areas and road/highways. Land use and human activities largely determine the nature and level of pollutants. Among the various types of pollutants that can contribute to adverse water quality impact in receiving water bodies, of concern are suspended solids, heavy metals, polycyclic aromatic hydrocarbons and nutrients. This paper provides a critical review of the characteristics and sources of urban stormwater pollutants and the manner in which the pollution occurs. Treatment systems for urban stormwater runoff and for urban stormwater harvesting are discussed.
Aryal, R, Vigneswaran, S, Kandasamy, JK, Baral, B & Grasmick, A 2010, 'Influence of aeration and permeate flux on deposition of particulates on membrane surface', Water Science & Technology: Water Supply, vol. 10, no. 6, pp. 979-986.View/Download from: UTS OPUS or Publisher's site
In microfiltration, a deposit of foulant tends to form on the membrane surface and this usually controls the performance of the filtration process. This paper discusses the influence of physical parameters such as aeration and permeates flux on migration and deposition of above micron particles on the membrane surface. Kaolin clay suspension of particle 3.7â8 mm with mean particle diameter 4.1 mm was used in this study. Equal amount of mass of deposited particles on the membrane surface created different transmembrane pressure (TMP) when operated at different aeration rates and permeate flux showing that there is a composite effect. The particle deposition rate at the beginning at lower flux was almost linear which changed to a sharp logarithamic rise at higher flux. The difference in TMP rise for the same amount of deposit demonstrated the selective nature of particle deposition. The mass of the particle deposition on the membrane surface could be described by two parameters: maximum deposition and time using a simple empirical logarithamic equation y=k/[1+exp(b-at)], where k, a, and b are constant; y is the particulate mass deposit (g/m2) and t is the time. The maximum particle mass deposition growth could be described by the equation dy/dt=1/4ka.
Chanan, AP, Kandasamy, JK, Vigneswaran, S, Spyrakis, G, Ghetti, I & idris, E 2010, 'Applied Rainwater Harvesting Education: An Australian Case Study', Journal of Environmental Science and Engineering, vol. 4, no. 3, pp. 32-35.View/Download from: UTS OPUS
Rainwater tanks have been an integral part of the Australian landscape given the vital role these tanks have played over the years in rural Australia. In the past Local government and Water Authorities actively discouraged the use of rainwater tanks and informing citizens that they were illegal and dangerous. Kogarah Council within the Sydney metropolitan area is a proactive Council, and became the first council in Sydney to adopt Total Water Cycle Management (TWCM) principles into its Sustainability Management Plan, integrating these principles into on-ground projects at a catchment level in a planned and strategic approach. Among it priority projects was the Rainwater Tanks in Schools. This paper outlines how this project assisted all 22 schools in the Kogarah LGA (The Local Government Association) to increase the efficiency of water use and install rainwater tanks to reduce potable water use in toilet flushing and irrigating school gardens. The rainwater harvesting reduced the amount of drinking water used for toilet flushing and/or irrigation. The rainwater tanks also act as a visual reminder to conserve water for the students. The project has equipped the next generation with the necessary tools to make informed decisions and undertake actions that will move towards achieving sustainability.
Chanan, AP, Vigneswaran, S & Kandasamy, JK 2010, 'Valuing stormwater, rainwater and wastewater in the soft path for water management: Australian case studies', Water Science And Technology, vol. 62, no. 12, pp. 2854-2861.View/Download from: UTS OPUS or Publisher's site
A Water Sensitive City is now commonly acknowledged best practice for designing the cities of the future. In Australia, the National Water Initiative has allocated high priority towards offering insight into successful water sensitive urban development projects, to facilitate capacity building within the industry. This paper shares innovative water sensitive projects implemented at Kogarah City Council, in Sydney. Four key projects are discussed, demonstrating how stormwater, rainwater and wastewater can be incorporated into decentralised water systems to offer sustainable water management of the future. The case studies included in the paper highlight Kogarahâs journey towards the Soft Path for Water Management.
Erdei, L, Vigneswaran, S & Kandasamy, JK 2010, 'Modelling of submerged membrane flocculation hybrid systems using statistical and artificial neural networks methods', Journal of Water Supply: Research and Technology. AQUA, vol. 59, no. 2-3, pp. 198-208.View/Download from: UTS OPUS or Publisher's site
Hybrid membrane filtration processes involve complex physical, chemical and biological phenomena, thus their mechanistic modelling is challenging. The chief advantages of statistical and artificial neural networks (ANN) models (data-driven models) are that they do not require assumptions and simplifications to establish relationships from data. This paper investigates the characteristics and performance of several data-driven methods to model a hybrid membrane system. The focus is on the application of regression analysis and artificial intelligence based methods to a steady-state system. Among empirically based approaches, ANN neural networks methods were found to be very useful to predict permeate quality and membrane fouling. In the past multivariate nonlinear regression had barely been investigated for process modelling in water and waste water treatment. In this study polynomial multivariate nonlinear regression showed a superior performance. Multivariate parametric nonlinear models could match the performance of the nonparametric ANN models in the empirical modelling of complex systems, especially when combined with advanced optimization methods. This paper gives the methodology of how one could optimize a membrane hybrid system using ANN, validating it with one set of data. The same procedure/methodology can be applied to similar systems.
Guo, W, Zhang, R, Vigneswaran, S, Ngo, H & Kandasamy, JK 2010, 'Membranes coupled with physico chemical treatment in water reuse', Water Science and Technology, vol. 61, no. 2, pp. 513-519.View/Download from: UTS OPUS or Publisher's site
In this study, short-term experiments were conducted with different configurations of membrane hybrid systems to treat biological treated sewage effluent containing refractory organic pollutants: (i) submerged hollow fiber microfiltration (SMF) alone; (ii) spiral flocculator (SF)-SMF without settling; (iii) SF-PAC-SMF without settling and (iv) SMF with magnetic ion exchange resin MIEXw pretreatment. The results indicated that the pre-flocculation of SF could improve the mitigation of membrane fouling significantly even when the system was operated at a high membrane filtration rate. The transmembrane pressure (TMP) of SF-PAC-SMF only increased marginally (0.8 kPa over 8 hours). SF-SMF without the addition of powdered activated carbon (PAC) also took a relatively long duration for the TMP to increase. The TMP only increased by 2.5 kPa over 8 hours. The SF-PAC-MF system resulted in a high dissolved organic carbon (DOC) removal of more than 96%. When used as pre-treatment to submerged membranes, the fluidized bed MIEXw contactor could remove a significant amount of organic matter in wastewater. This pre-treatment helped to reduce the membrane fouling and kept the TMP low during the membrane operation.
Ho, D, Senthilnanthan, M, Mohammad, J, Vigneswaran, S, Ngo, H, Mahinthakumar, G & Kandasamy, JK 2010, 'The Application Of Photocatalytic Oxidation In Removing Pentachlorophenol From Contaminated Water', Journal of Advanced Oxidation Technologies, vol. 13, no. 1, pp. 21-26.View/Download from: UTS OPUS
The degradation of sodium salt of pentachlorophenol (PCPS) by photocatalysis with titanium dioxide (TiO2) as the catalyst was investigated. The residual PCPS after photo-degradation was analyzed by high performance liquid chromatograph (HPLC) while the c
Johir, MH, Vigneswaran, S & Kandasamy, JK 2010, 'Hybrid filtration method for pre-treatment of stormwater', Water Science And Technology, vol. 62, no. 12, pp. 2937-2943.View/Download from: UTS OPUS or Publisher's site
In this study the hybrid filtration process (combining fibre filter with deep bed dual media filtration) was investigated as pre-treatment to stormwater. This process was investigated in-terms of reduction in turbidity, dissolved organic carbon (DOC), colour, headloss development across the filters, suspended solids removal, organic matter removal, nutrients and heavy matter (such as iron, copper, lead, zinc) removal efficiency. A comparison was made between the hybrid filter with single media (sand) deep bed filter and fibre filter. It was found that the hybrid filtration system successfully removed turbidity (98%), colour (99%), suspended solids (99%), and DOC (55%). The removal efficiency of heavy metal was relatively low as the concentration of heavy metals present in stormwater was low. The removal efficiency of nitrate, nitrite and phosphorous (as orthophosphate) was 27, 35 and 72% respectively. Hybrid filtration processes showed a better reduction of Modified Fouling Index (MFI) value (from 15.500 s/l2 to 9 s/l2) compared with single media sand, anthracite and fibre filter which were 35 s/l2, 13 s/l2 and 14 s/l2 respectively when operated at FeCl3 dose of 15 mg/l.
Mohammed Abdul, J, Vigneswaran, S, Shim, WG & Kandasamy, JK 2010, 'Removal of metsulfuron methyl by granular activated carbon adsorption', Desalination and Water Treatment, vol. 21, no. 1-3, pp. 247-254.View/Download from: UTS OPUS or Publisher's site
The removal of metsulfuron methyl (MSM) from aqueous solution (a sulfonyl urea herbicide) was investigated by adsorption both in batch and fixed bed processes. Coal based granular activated carbon (GAC) was used as an adsorbent. The adsorption equilibrium, isotherms and kinetics of MSM were studied and the data was fitted into various mathematical models. The adsorption equilibrium was fitted by Langmuir and Freundlich isotherms. Homogeneous surface diffusion model (HSDM) kinetic equation with Langmuir and Freundlich adsorption isotherm model was successfully applied to predict the adsorption kinetics data for various concentrations of MSM. The average mass transfer coefficients (kf) were 2.125 105 and 2.198 105 m/s with the Langmuir and Freundlich adsorption isotherm model, respectively. The Bohart-Adams, Thomas, and Yoon and Nelson empirical models were attempted to fit long term column adsorption data. Overall, the Thomas model was found to best simulate the fixed bed adsorption of MSM.
Nguyen, V, Vigneswaran, S, Ngo, H & Kandasamy, JK 2010, 'Arsenic removal by iron oxide coated sponge: Experimental performance and mathematical models', Journal of Hazardous Materials, vol. 182, no. 1-3, pp. 723-729.View/Download from: UTS OPUS or Publisher's site
Millions of people worldwide are at risk from the presence of arsenic in groundwater. In this study, adsorption equilibrium and long term experiments were carried out to evaluate the performance of iron oxide coated sponge (IOCSp) in arsenic removal. It was found that maximum adsorption capacity of IOCSp for As(III) and As(V) calculated by Sips isotherm was 4.2 and 4.6 mg/g of IOCSp, respectively. A filter packed with small amount of 25 g IOCSp maintained a consistent arsenic removal efficiency of 95% from synthetic solution containing arsenic concentration of as high as 1000g/L. This produced a throughput volume of 153 and 178 L of water containing As III) and As(V), respectively before any need for regeneration or disposal of IOCSp. IOCSp could be regenerated by washing it with NaOH solution. The dynamic (column) adsorption kinetics were successfully predicted by the Thomas and Nikolaidis modified models.
El Saliby, I, Shon, H, Okour, Y, Vigneswaran, S, Senthilnanthanan, M & Kandasamy, JK 2010, 'Production of Titanium Dioxide Nanoparticles and Nanostructures from Dye Wastewater Sludge - Characterisation and Evaluation of Photocatalytic activity', Journal of Advanced Oxidation Technologies, vol. 13, no. 1, pp. 15-20.View/Download from: UTS OPUS
Producing a useful catalyst (TiO2) from sludge is possible after the incineration of sludge produced from the flocculation of wastewater by Ti-salts. In this study, TiO2 was successfully produced from dye wastewater sludge. Titanate nanotubes and nanoaggregates were produced through alkaline-hydrothermal and hydrogen peroxide treatments, respectively. Catalysts were characterised using scanning electron microscope and BET surface measurement. The photocatalytic activity was monitored for the photodegradation of organics in synthetic wastewater (SWW) and the photodecomposition of gas acetaldehyde. Nanotubes with a high surface area of 155.83 m2/g were obtained by alkaline-hydrothermal treatment, while lower surface area (65.22 m2/g) nanoaggregates were synthesized after hydrogen peroxide treatment. In general, nanoparticles, nanotubes and nanoaggregates showed mild photocatalytic activity. All catalysts showed similar photocatalytic activity for the photodecomposition of organics in SWW and the photodecomposition of acetaldehyde.
Chanan, AP, Kandasamy, JK & Simmons, B 2009, 'Benefits of Local Government and University Research Alliances', Institution of Civil Engineers. Proceedings. Municip..., vol. 162, no. ME2, pp. 111-116.View/Download from: Publisher's site
Local government plays an integral role in the Australian economy with a cumulative annual expenditure of over Aus$20 billion representing around 2% of Australian GDP. Local government authorities employ around 1-3% of the Australian workforce and provide a wide range of services and infrastructure. There is a general lack of appreciation among council staff of the value of collaboration with universities and vice versa. However, staff at Kogarah Municipal Council, having been involved in partnership projects with universities, strongly value the benefits of such collaborations. Councils can provide a `one-stopshop for applied research and its application for a range of disciplines from science and technology to arts and policy studies.
Kus, BG & Kandasamy, JK 2009, 'Low-Cost Filtration System to Treat First-Flush Stormwater', Water, Air, & Soil Pollution: Focus, vol. 9, no. 5-6, pp. 347-355.View/Download from: UTS OPUS or Publisher's site
The aim of this paper is to evaluate the performance of the low-flow filtration system (LFFS) that Kogarah Municipal Council developed for treating and reusing the highly polluted first-flush stormwater (FFSW) while allowing the cleaner subsequent major stormwater flows to be directed to the major street drainage. The LFFS was evaluated through laboratory investigations using columns packed with different filter media to test the removal efficiency of pollutants such as zinc (Zn), total phosphorus (TP), total nitrogen (TN), total organic content, total petroleum hydrocarbons (TPH), and turbidity. The findings from this study demonstrate the effectiveness of the LFFS to largely reduce turbidity, TPH, and trace metals from the FFSW. The LFFS also partially removes dissolved organics, TP and TN. These pollutants are more commonly and effectively removed in subsequent processes of a stormwater treatment train. Further this paper highlights the importance of regular maintenance of the LFFS especially as it is only associated in removing the high pollutant loads during a storm event. Due to this first flush, a thick oily crust-formed layer requires monthly removal, and an entire replacement of the exhausted filter media is required quarterly. However considering the labor required to service the crust formed layer within the LFFS, it is more cost effective to replace the entire depth of filter media monthly.
Pezzaniti, D, Beecham, SC & Kandasamy, JK 2009, 'Influence of clogging on the effective life of permeable pavements', Water Management, vol. 162, no. 3, pp. 211-220.View/Download from: UTS OPUS or Publisher's site
This paper investigates the 'effective life' (or useful lifespan) of permeable pavement installations subject to sediment loadings. The broad aims of this study, which included both laboratory and field work components, were to improve understanding of the long-term pavement hydraulic conductivity, to assess the effective life of permeable pavements and to quantify the degree of sediment trapping and associated pollutant retention. Three types of permeable pavement were investigated. For each type the effects of pavement cleaning were also investigated. Over a simulated 35 years of sediment loading conducted in the laboratory, the results showed reductions of 59-75% in hydraulic conductivity with an average sediment retention of 94%. Suspended sediment concentrations measured at the outflow of the laboratory test beds did not show any significant difference between pavers that were subjected to cleaning and those that were not. For the field studies presented in this paper, hydraulic conductivities were very high in locations where permeable pavements are subjected to small to moderate sediment loads. At other locations with high coarse sediment and organic sediment loads, hydraulic conductivity tests indicated that clogging occurred at a rapid rate, particularly where runoff. owing onto the pavement was concentrated
Singh, G & Kandasamy, JK 2009, 'Evaluating performance and effectiveness of water sensitive urban design', Desalination and Water Treatment, vol. 11, no. 1-3, pp. 144-150.View/Download from: UTS OPUS or Publisher's site
Water Sensitive Urban Design (WSUD) is something of a catch-all term for environmentally sustainable water resource management in urban areas. Water sensitive urban design offers an alternative to the traditional conveyance approach to stormwater management. It seeks to minimise the extent of impervious surfaces and mitigate changes to the natural water balance, through on-site reuse of water as well as through temporary storage. By integrating major and minor fl ow paths in the landscape and adopting a range of water sensitive design techniques, the size of the structural stormwater system required can be signifi cantly reduced. WSUD techniques include detention and retention basins to lower peak fl ows, grassed swales and vegetation to facilitate water infi ltration and pollutant fi ltration. WSUD has been adopted widely in Australia and is being implemented in varied local government areas. The major challenge to the success of WSUD is however its measure of effectiveness over the life cycle given that it demands high maintenance. The aim of this paper is to provide a snapshot of effectiveness of WSUD implemented in Kogarah Municipal Council using two case studies and presents results on improvement in water quality through both site specifi c and water quality monitoring of the bays.
Aryal, R, Lebegue, J, Shon, H, Vigneswaran, S, Kandasamy, JK & Grasmick, A 2009, 'Temporal variation of foulant characteristics in membrane bioreactor', Desalination and Water Treatment, vol. 6, no. 1-3, pp. 69-73.View/Download from: UTS OPUS
Many studies have been performed to analyse the influence of compounds present in different fractions of the membrane foulants. The aim of this study was to reveal the changing chemistry of compounds present in membrane foulant with the evolution of time. Membrane fouling in a side stream membrane bioreactor (MBR) reactor was investigated. Constant flux filtration was employed in an MBR operation. Air bubbles were injected at 2 m3 h1 m2 for six different durations (2, 4, 6, 9, 15 and 20 days) of MBR operation. The foulant on the membrane surface was extracted using NaOH solution (5%) and analysed using fluorescent spectroscopy. The spectra showed the changing chemistry of foulant with the evolution of time. It showed low molecular weight substances such as amino acids and small aromatic proteins were dominant in the foulant at the beginning of the experiment but its concentration decreased with time. On the other hand BOD5 type substances concentration increased with time from the beginning of the experiment up to 9 days and there after decreased. The concentration of larger molecular weight soluble microbial by-products increased with evolution of time. Air bubbles at two aeration rate of 1m3 h1m2 and 2 m3 h1 m2 were also injected from the bottom of the membrane tanks to produce shear stresses on the membrane surface during 5 days of MBR operation to compare the effect of aeration in fouling propensity.
Chinu, KJ, Johir, MH, Vigneswaran, S, Shon, H & Kandasamy, JK 2009, 'Biofilter as pretreatment to membrane based desalination: Evaluation in terms of fouling index', Desalination, vol. 247, no. 1-3, pp. 77-84.View/Download from: UTS OPUS or Publisher's site
The removal of particulate matter and dissolved organic matter from seawater by the use of biofiltration was investigated. Granular activated carbon (GAC) and anthracite were used as biofilter media at two different filtration velocities. Filtrate quality was measured in terms of silt density index (SDI), modified fouling index (MFI) and turbidity removal. Reverse osmosis (RO) was used as a post-treatment. Both biofilters demonstrated similar fouling reduction behavior in terms of SDI and MFI. Fouling potential in terms of MFI values decreased to 10 s/L2 within the first 10â15 days of operation and kept constant up to the remaining experimental period of 55 days of operation for both GAC and anthracite biofilter. The filtrate turbidity was steady after 10 days and remained low at a value of 0.2â0.3 NTU and 0.28â0.31 NTU for anthracite and GAC biofilter, respectively. Furthermore, the headloss development was low and within 20 cm for biofilter operated at a low velocity of 5 m/h. A post-treatment of reverse osmosis after a pretreatment of GAC and anthracite biofilters showed a reduction in normalized flux decline (J/J0) from 0.22 to 0.12 and 0.35 to 0.21 during the first 20 h, respectively. The RO flux for seawater declined at a faster rate and continued even after 3 days when no pretreatment was provided.
Lee, J, Johir, J, Chinu, KJ, Shon, H, Vigneswaran, S, Kandasamy, JK, Kim, CW & Shaw, K 2009, 'Hybrid filtration method for pre-treatment of seawater reverse osmosis (SWRO)', Desalination, vol. 247, no. 1-3, pp. 15-24.View/Download from: UTS OPUS or Publisher's site
Hybrid processes combining fi bre fi lter with deep bed fi ltration process such as (i) fi bre fi lter and sand fi lter, (ii) fi bre fi lter and anthracite and (iii) fi bre fi lter and dual media fi lter were investigated as pre- treatments to SWRO. Seawater was drawn from Chowder Bay, Sydney. The eff ect of diff erent pretreatment hybrid systems was investigated in terms of silt density index (SDI10), modifi ed fouling index (MFI), headloss across the fi lters and reduction in turbidity and dissolved organic carbon (DOC). The in-line fl occulation in fi bre fi lter improved the performance of the pretreatment hybrid system as measured by the MFI, SDI10, headloss, turbidity and DOC removal. The lowest SDI10 and MFI were found with a fi bre fi lter operated at a fi ltration velocity of 40 m/h followed by dual media fi lter operated at a fi ltration velocity of 5 m/h. The lowest headloss and turbidity was found with a fi bre fi lter operated at a fi ltration velocity of 40 m/hr followed by anthracite operated at a fi ltration velocity of 5 m/h. This system also gave an effl uent with the lowest DOC of 0.64 mg/L corresponding to a removal effi ciency of about 70%.
Mohammed Abdul, J, Vigneswaran, S, Shon, H, Areerachakul, N & Kandasamy, JK 2009, 'Comparison of granular activated carbon bio-sorption and advanced oxidation processes in the treatment of leachate effluent', Korean Journal Of Chemical Engineering, vol. 26, no. 3, pp. 724-730.View/Download from: UTS OPUS or Publisher's site
Nguyen, V, Vigneswaran, S, Ngo, H, Shon, H & Kandasamy, JK 2009, 'Arsenic removal by a membrane hybrid filtration system', Desalination, vol. 236, no. 1-3, pp. 363-369.View/Download from: UTS OPUS or Publisher's site
Arsenic is a toxic semi-metallic element that can be fatal to human health. Membrane filtration can remove a number of contaminants from water, including arsenic. Removal of arsenic by membrane filtration is highly dependent on the species of arsenic and the properties of the membrane. The performance of the nanofilter is better for removing As(V) than As(III). About 57% of As(III) and 81% of As(V) was removed from 500 mg/L arsenic solutions by nanofiltration (NTR729HF, Nitto Denko Corp., Japan) of 700 molecular weight (MW) cutoff. The removal efficiency of microfiltration (MF) was much lower than that of nanofiltration (NF) due to its larger pore size. By comparison only 37% of As(III) and 40% of As(V) were removed by microfiltration (PVA membrane, Pure-Envitech, Korea). However, the removal efficiency of microfiltration was increased dramatically when a small amount of nanoscale zero valent iron (nZVI) was added. The removal efficiency by MF increased up to 90% with As(V) and 84% with As(III) when an amount of 0.1 g/L of nZVI was added into the arsenic solution.
Shon, H, Vigneswaran, S, Kandasamy, JK, Kim, JB, Park, HJ, Choi, S & Kim, JH 2009, 'Preparation of titanium oxide, iron oxide, and aluminium oxide from sludge generated from Ti-salt, Fe-salt and Al-salt flocculation of wastewater', Journal of Industrial and Engineering Chemistry, vol. 15, no. 5, pp. 719-723.View/Download from: UTS OPUS or Publisher's site
In this study, the settled floc (sludge) produced by aluminum sulfate (Al2(SO4)3), ferric chloride (FeCl3) and titanium tetrachloride (TiCl4) flocculation was recycled with a novel flocculation process, which has a significant potential to the lower cost of waste disposal, protect the environment and public health and yield economically useful by-products. Three coagulants removed 70% of organic matter in synthetic wastewater. The settled floc was incinerated in the range from 100 8C to 1000 8C. Alumina (Al2O3), hematite (Fe2O3), titanium oxide (TiO2) which are the most widely used metal oxides were produced from the wastewater sludge generated by the flocculation in wastewater with Al2(SO4)3, FeCl3 and TiCl4, respectively. TiO2 particles produced from the sludge consisted of the large amount of nano size particles. Hematite (Fe2O3) and grattarolaite (Fe3 (PO4)O3 or Fe3PO7) included the majority of micro size (40%) particles. Alumina (Al2O3) also consisted of micro size (40%). Due to TiO2 usefulness of the application, detailed characterisation of TiO2 after calcination at different temperatures were investigated in terms of X-ray diffraction, energy dispersive X-ray, surface area and photoactivity.
Shon, H, Vigneswaran, S, Kandasamy, JK, Zareie, HM, Kim, JB, Cho, DL & Kim, JH 2009, 'Preparation and Characterisation of Titanium Dioxide (TiO2) from Sludge produced by TiCl4 Flocculation with FeCl3, Al2(SO4)3 and Ca(OH)2 Coagulant Aids in Wastewater', Separation Science and Technology, vol. 44, no. 7, pp. 1525-1543.View/Download from: UTS OPUS or Publisher's site
In this study, TiCl4 coagulant together with coagulant aids such as FeCl3, Al2(SO4)3, and Ca(OH)2 were investigated to improve the photoactivity of titanium dioxide (TiO2) produced from sludge and to increase the resulting low pH value. After TiCl4 flocculation with three coagulant aids, the settled floc (sludge) was incinerated at 600Â°C to produce TiO2 doped with Fe, Al, and Ca elements. Fe-, Al-, and Ca-doped TiO2 was characterized in terms of structural, chemical, and photo-electronic properties. All the coagulant aids used together with Ti-salt flocculation effectively increased the pH values. The surface area of TiO2-WO (without any coagulant aids), Fe/TiO2, Al/TiO2, and Ca/TiO2 was 122 m2/g, 77 m2/g, 136 m2/g and 116 m2/g, respectively. The TiO2-WO, Fe/TiO2, Al/TiO2, and Ca/TiO2 was found to be of anatase phase. The XRD pattern on the Fe/TiO2 included an additional peak of hematite (Î±-Fe2O3). The majority of gaseous acetaldehyde with TiO2-WO and Ca/TiO2 for photocatalytic activity was completely removed within 40 minutes under UV irradiation.
Areerachakul, N, Kitiphatmontree, M, Kandasamy, JK, Kus, BG, Duangduen, C, Pivsa-Art, S & Vigneswaran, S 2009, 'Submerged Membrane System with Biofilter as a Treatment to Rain Water', Water, Air, & Soil Pollution: Focus, vol. 9, no. 5-6, pp. 431-438.View/Download from: UTS OPUS
Rainwater has been used as drinking water in Thailand for centuries especially in the rural parts and is accepted as an important water resource. From past to present, the quality of rainwater has changed with the landuse of the landscape, and its water quality is influenced by a diverse range of conditions such as the management of pollutant sources, the catchment condition, wind and meteorological conditions, and the location of rainwater collection points. In this study, the quality of rainwater collected off roofs at several locations was examined. Granular activated carbon (GAC) filtration was used as a pretreatment to microfiltration (MF) to remove the dissolved organic matter (DOC). After an initial adsorption period, the biofilm that formed on the GAC (biofilter) was found to remove DOC by up to 40%, 35%, and 15% for bed filter depths of 15, 10, and 5 cm, respectively. Biofilters also removed nitrate and phosphate by more than 80% and 35%. The hollow fiber membrane microfiltration with pore size of 0.1 Î¼m was used to treat the effluent from biofiltration to remove the microorganisms/pathogens in the rainwater. Although there was no significant additional removal of DOC by MF, the biofilter removed all microorganisms. The use of biofilters as pretreatment to MF/UF could remove a higher amount of DOC, remove microorganisms, increase the membrane treatment efficiency, and reduce membrane fouling.
Aryal, R, Kandasamy, JK, Vigneswaran, S, Naidu, R & Lee, S 2009, 'Review of Stormwater Quality, Quantity and Treatment Methods Part 2: Stormwater: Quality Modelling', Environmental Engineering Research, vol. 14, no. 3, pp. 143-149.View/Download from: UTS OPUS
In this paper, review of stormwater quality and quantity in the urban environment is presented. The review is presented in three parts. This second part reviews the mathematical techniques used in stormwater quality modelling and has been undertaken by examining a number of models that are in current use. The important features of models are discussed.
Aryal, R, Kandasamy, JK, Vigneswaran, S, Naidu, R & Lee, SH 2009, 'Review of Stormwater quality, Quantity and Treatment Methods Part 1', Environmental Engineering Research, vol. 14, no. 2, pp. 71-78.View/Download from: UTS OPUS
A review of stormwater quantity and quality in the urban environment is presented. The review is presented in three parts. The first part reviews the mathematical methods for stormwater quantity and has been undertaken by examining a number of stormwater models that are in current use. The important feature of models, their applications, and management has been discussed. Different types of stormwater management models are presented in the literatures. Generally, all the models are simplified as conceptual or empirical depending on whether the model is based on physical laws or not. In both cases if any of the variables in the model are regarded as random variables having a probability distribution, then the model is stochastic model. Otherwise the model is deterministic (based on process descriptions). The analytical techniques are presented in this paper.
Aryal, R, Legegue, J, Vigneswaran, S, Kandasamy, JK, Heran, M & Grasmick, A 2009, 'Identification and characterisation of biofilm formed in membrane bioreactor', Separation and Purification Technology, vol. 67, no. 1, pp. 86-94.View/Download from: UTS OPUS or Publisher's site
Experiments were conducted in a laboratory scale membrane bio-reactor (MBR) system equipped with a side stream flat sheet membrane. Six runs lasting different durations (2, 4, 6, 9, 15 and 20 days) were conducted at an aeration rate of 2 m3 h-1 m-2 to understand the temporal variation of chemistry of foulant that attached on the membrane surface. The foulant attached on the membrane surface was extracted with 0.5% (v/v) NaOH solution and the extract was analysed using fluorescent spectroscopy and size exclusion chromatography. Variation of low- and high-molecular weight substances with evolution of time was compared. The results showed that the nature of foulant changed with the evolution of time. Four runs conducted for a short duration (2, 4, 6 and 9 days), low-molecular weight substances were dominant in the foulant whereas for long duration runs (15 and 20 days), high-molecular weight substances were mainly observed. Moreover, the foulant close to the membrane surface contained mainly protein and soluble microbial by-products.
Chanan, AP, Kandasamy, JK, Vigneswaran, S & Sharma, D 2009, 'A gradualist approach to address Australia's urban water challenge', Desalination, vol. 249, no. 3, pp. 1012-1016.View/Download from: UTS OPUS or Publisher's site
There is growing consensus worldwide against the conventional centralised approach to water management, and a âsoft pathâ for water management has emerged as a sustainable alternative. A âsoft pathâ for water management emphasizes the optimization of end-use efficiency, small-scaled management systems, incorporates fit-for-purpose water use, and recommends the use of diverse, locally appropriate and commonly decentralised infrastructures. However, large-scale desalination plants are currently being built for almost all metropolitan centres in Australia to ensure water supply security. Unlike âsoft pathâ for water management, large-scale desalination plants embody the traditional urban water supply approach. In spite of knowledge and values relating to the water cycle having shifted towards âsoft pathâ, the old organisational framework is believed to be hindering its adoption. Perhaps, therefore major water utilities in recent times have opted for the ideologically easier option of large-scale desalination conforming to the existing framework, instead of choosing a âsoft pathâ for water management with potential for decentralised management. This paper critically reviews the urban water management direction in metropolitan Australia and puts forward a âgradualist approachâ. It incorporates a comprehensive non-potable water reuse program necessary to build the familiarity and trust in water reuse, as a first step before introducing the idea of potable reuse.
Johir, MH, Lee, J, Vigneswaran, S, Kandasamy, JK & Shaw, K 2009, 'Treatment of Stormwater using Fibre Filter Media', Water, Air, & Soil Pollution: Focus, vol. 9, no. 5-6, pp. 439-447.View/Download from: UTS OPUS or Publisher's site
In this study, a high-rate fibre filter was used as a pre-treatment to stormwater in conjunction with in-line flocculation. The effect of operating the fibre filter with different packing densities (105, 115 and 125 kg/m3) and filtration velocities (20, 40, 60 m/h) with and without in-line flocculation was investigated. In-line flocculation was provided using 5, 10 and 15 mg/L of ferric chloride (FeCl3Â·6H2O). The filter performance was studied in terms of pressure drop (ÎP), solids removal efficiency, heavy metals (total) removal efficiency and total organic carbon (TOC) removal efficiency. It is found that the use of in-line flocculation at a dose of 15 mg/L improved the performance of fibre filter as measured by turbidity removal (95%), total suspended solids reduction (98%), colour removal efficiency (99%), TOC removal (reduced by 30â40 %) and total coliform removal (93%). The modified fouling index reduced from 750â950 to 12 s/L2 proving that fibre filter can be an excellent pre-treatment to membrane filtration that may be consider as post-treatment. The removal efficiency of heavy metal was variable as their concentration in raw water was small. Even though the concentration of some of these metals such as iron, aluminium, copper and zinc were reduced, others like nickel, chromium and cadmium showed lower removal rates
Johir, MH, Vigneswaran, S & Kandasamy, JK 2009, 'Deep bed filter as pre-treatment to stormwater', Desalination and Water Treatment, vol. 12, no. 1-3, pp. 313-323.View/Download from: UTS OPUS or Publisher's site
This paper presents the results of experiments on the application of dual media and single media deep bed filters as pre-treatments to stormwater. In-line flocculation-filtration experiments were conducted with dual and single media filter. The single filter media (80 cm) consisted of either anthracite or sand, and the dual media filter consisted of sand (40 cm at the bottom) and anthracite (40 cm on top). Filtration velocities of 5 m/h, 10 m/h and 15 m/h were examined. The removal efficiency for turbidity, suspended solids and TOC was found to be 95%, 99% and 30â45% respectively at a flocculant dose of FeCl3 of 15 mg/L. The anthracite filter media showed a lower headloss development (26 cm, operated at 5 m/h filtration velocity with FeCl3 dose of 5 mg/L). The removal efficiency for nitrogen was lower than phosphorus which was relatively good (up to 50%). The removal efficiency for heavy metals such as Cd, Pb, Cr and Ni was found to be very low for all tested filtration systems because concentrations of these metals in the influent were also low. This filter can be used as a pretreatment to a membrane filter as the modified fouling index was reduced from 750 s/L2 (for stormwater) to 15 s/L2 (for filtered effluent). Detailed submerged membrane filter experiments conducted with pre-treated water showed that the membrane filter can be successfully be used as post-treatment to in-line flocculant-filter at a sustainable flux of 10 L/m2.h to remove the remaining solids and pathogens. An increase of air scouring in the membrane unit decreased the pressure development although it did not have any effect on increasing the critical flux beyond 10 L/m2.h.
Nguyen, V, Nguyen, T, Pham, TL, Vigneswaran, S, Ngo, H, Kandasamy, JK, Nguyen, H & Nguyen, TD 2009, 'Adsorption and removal of arsenic from water by iron ore mining waste', Water Science and Technology, vol. 60, no. 9, pp. 2301-2308.View/Download from: UTS OPUS or Publisher's site
There is a global need to develop low-cost technologies to remove arsenic from water for individual household water supply. In this study, a purified and enriched waste material (treated magnetite waste, TMW) from the Trai Cau's iron ore mine in the Thai Nguyen Province in Vietnam was examined for its capacity to remove arsenic. The treatment system was packed with TMW that consisted of 75% of ferrous-ferric oxide (Fe3O4) and had a large surface area of 89.7 m2/g. The experiments were conducted at a filtration rate of 0.05 m/h to treat groundwater with an arsenic concentration of 380 mg/L and iron, manganese and phosphate concentrations of 2.07 mg/L, 0.093 mg/L and 1.6 mg/L respectively. The batch experimental results show that this new material was able to absorb up to 0.74 mg arsenic/g. The results also indicated that the treatment system removed more than 90% arsenic giving an effluent with an arsenic concentration of less than 30 mg/L while achieving a removal efficiency of about 80% for Mn2 + and PO43-. This could be a promising and cost-effective new material for capturing arsenic as well as other metals from groundwater
Nguyen, V, Rahman, A, Vigneswaran, S, Ngo, H, Kandasamy, JK, Nguyen, TD, Do, AT & Nguyen, KT 2009, 'Arsenic removal by iron oxide coated sponge: treatment and waste management', Water Science and Technology, vol. 60, no. 6, pp. 1489-1495.View/Download from: UTS OPUS or Publisher's site
One of the problems in drinking water that raises concern over the world is that millions of people still have to use arsenic-contaminated water. There is a worldwide need to develop appropriate technologies to remove arsenic from water for household and community water supply systems. In this study, a new material namely iron oxide coated sponge (IOCSp) was developed and used to remove arsenic (As) from contaminated groundwater in Vietnam. The results indicated that IOCSp has a high capacity in removing both As (V) and As (III). The adsorption capacity of IOCSp was up to 4.6mg As/g IOCSp, showing better than many other materials. It was observed from a pilot study that a small quantity of IOCSp (180 g) could reduce As concentration of 480mg/L in 1.5m3 of contaminated natural water to below 40 mg/L. In addition, an exhausted IOCSp, containing a large amount of arsenic (up to 0.42 wt %) could safely be disposed through the solidification/stabilization with cement. Addition of fly ash also reduced the amount of arsenic in the leachate.
Zhang, R, Chinu, KJ, Vigneswaran, S & Kandasamy, JK 2009, 'Submerged microfiltration coupled with physico-chemical processes as pretreatment to sea water desalination', Desalination and Water Treatment, vol. 11, no. 1-3, pp. 52-57.View/Download from: UTS OPUS or Publisher's site
In this study, the critical fl ux of the submerged membrane system was experimentally evaluated when it was used for seawater with and without pre-treatment. In this study, different processes such as fl occulation with ferric chloride (FeCl3) and different doses of PAC adsorption were used as a pre-treatment. The pretreatment of fl occulant of 2 mg/L of FeCl3 and adsorption with the dose of 1 g/L PAC showed an improvement in the critical fl ux from 5 L/m2.h to 6.7 L/m2.h and 13.3 L/m2.h respectively. The performance of these pretreatments was also determined in terms of modifi ed fouling index using ultrafi lter membrane (UF-MFI). UF-MFI and SDI indicated that PAC adsorption was a better pretreatment than fl occulation for the seawater used in this study. Molecular weight distribution (MWD) of seawater organic matter was also examined after different pretreatments. MWD of the raw seawater was mainly in the range from 1510 to 130 Da. It is observed that FeCl3 fl occulation and PAC adsorption as pretreatments partially removed the organic matter of 1510 Da and 130Da respectively
El Saliby, I, Okour, Y, Shon, H, Kandasamy, JK & Kim, IS 2009, 'Desalination plants in Australia, review and facts', Desalination, vol. 247, no. 1-3, pp. 1-14.View/Download from: UTS OPUS or Publisher's site
Australia is the driest continent on earth and despite this the installed desalination capacity is still around 1% of the total world's desalination capacity. This paper reviews the main seawater issues considered in every desalination projectâthe history, the present situation and the future of desalination in Australia, the suitability of applying reverse osmosis (RO) and the project details of two desalination plants (Sydney and Perth). Ocean currents, seawater temperature and salinity are signifi cant indicators in the assessment of the feasibility of desalination as they aff ect the production costs, the maintenance frequency and the quality of the product water. Seawater reverse osmosis (SWRO) is the only type of desalination technology currently used or proposed for future large-scale desalination plants in Australia. Every capital city except Darwin has considered building at least one desalination plant as a means of providing water security after several years of unprecedented drought that has signifi cantly reduced dam storage levels. Perth was the fi rst major city to use desalinated water for drinking water supply and by early 2009 Sydney will be the second city. Thirteen other large-scale SWRO plants are being planned or proposed at several locations for the purpose of supplying drinking water.
El Saliby, I, Okour, Y, Shon, H, Vigneswaran, S, Kandasamy, JK & Kim, JH 2009, 'Detailed Investigation on the Effect of Washing TiO2 Prepared from Ti-salts Flocculated Wastewater Sludge', Journal of Advanced Oxidation Technologies, vol. 12, no. 2, pp. 194-201.View/Download from: UTS OPUS
In this study, the effect of washing TiO2 produced from flocculated sludge was investigated. Produced TiO2 was washed with HCl, NaOH and Milli-Q-water and the washed TiO2 was then characterized in terms of X-ray diffraction imaging, scanning electron microscope/energy dispersive using X-ray analysis and surface area. Washed TiO2 was tested for adsorption and photocatalytic oxidation of acetaldehyde, and the decomposition of organics from synthetic wastewater (SWW) in terms of total organic carbon (TOC) and absorbance at UV-254. Results revealed that the anatase structure was dominant and TiO2 was mainly doped with C atoms. The surface area of TiO2 generated form TiCl4 flocculation was found to be twice larger than the TiO2 generated from Ti(SO4)2 flocculation. Acid and base washings of TiO2 improved its photocatalytic ability in decomposing acetaldehyde under UV-irradiation. Similarly, acid, base and Milli-Q water washings of TiO2 were better in reducing TOC and humic acids from SWW.
Aryal, R, Lee, B, Karki, R, Gurung, A, Kandasamy, JK, Pathak, B, Sharma, S & Giri, N 2008, 'Seasonal PM10 dynamics in Kathmandu valley', Atmospheric Environment, vol. 42, no. 37, pp. 8623-8633.View/Download from: UTS OPUS or Publisher's site
Data on ambient PM10 levels from six locations in the Kathmandu Valley recorded by means of continuous sampling using low volume air samplers from October 2002 to March 2007 were used to investigate PM10 concentration dynamics in the valley. Monthly average data of the urban areas, which have much higher concentrations than the rural areas, even exceeded the daily standard level of PM10, in Nepal, 120 ?m m-3. Repetitive peaks and troughs each year indicated annual patterns. Monthly average showed seasonal patterns are different between rural area and urban sites. The highest monthly average concentration was observed in February, the end of winter in urban areas where as in rural found in spring, and the lowest concentration was observed in July (monsoon period). The continuous increase in PM10 concentration from December to February in urban areas showed accumulation of PM10 in the ambient air during the wintertime. Rainfall in June and September, during the monsoon period, caused a PM10 concentration decrease, demonstrating that precipitation is effective in removing PM10 from the valley. Cross correlation analyses among the PM10 levels measured simultaneously at the sampling stations showed a poor relationship in winter; however, there were good relationships in the monsoon and post-monsoon seasons. Both the PM10 concentration and the air-mixing environment in the valley were closely associated with the temperature and wind speed.
Kandasamy, JK, Beecham, SC & Dunphy, AJ 2008, 'Stormwater sand filters in water sensitive urban design', Water Management - Proceedings of the Institution of Civil Engineers, vol. 161, no. WM2, pp. 55-64.View/Download from: UTS OPUS or Publisher's site
This paper investigates the suitability of sand filters for harvesting and treating stormwater for non-potable reuse purposes. A stormwater sand filtration device was constructed in a small urban catchment in Sydney, Australia. A sand filter is typically used in water-sensitive urban design (WSUD) as a component of a treatment train to remove pollution from stormwater before discharge to receiving waters, to groundwater or for collection and reuse. This paper describes an 18 month field study undertaken to determine the effectiveness and pollutant removal efficiency of a sand filter, and the differences in the pollutant removal efficiency of two grades of sand. A comparison of pollutant removal with previous literature on sand filters showed similar efficiencies but nutrient removal was higher than expected. A further unexpected result was that the coarse filter media performed as well as the fine media for most pollutant types and was superior in suspended solids removal. Improved modelling equations for predicting suspended solids and total phosphorus removal in sand filters are also presented in this paper.
Kannapiran, A, Chanan, AP, Singh, G, Tambosis, P, Jeyakumaran, JM & Kandasamy, JK 2008, 'Strategic asset management planning of stormwater drainage systems', Water Practice & Technology, vol. 3, no. 3, pp. 1-8.View/Download from: UTS OPUS or Publisher's site
Management of the urban water cycle in an integrated manner is an essential task to protect, restore and enhance in a sustainable manner. Strategic asset management planing is being developed as local government authorities face many challenges associated with managing the urban water cycle system. Statistical or conventional mathematical modelling approach has been found not practical for assessment of deteriorating infrastructures. Alternatively, application of fuzzy-based models is found more suitable as it links engineering judgment, experience and scarce field data of the deteriorating assets. In this study, a representative network of buried stormwater system's data is drawn and a pipe condition index is derived by linking the field data and reasoning using fuzzy approach. The inferred results are found to be useful and relevant for asset maintenance and future development programs.
Sabina, L, Kus, BG, Shon, H & Kandasamy, JK 2008, 'Membrane fouling propensity after adsorption as pretreatment in rainwater: a detailed organic characterisation', Water Science And Technology, vol. 58, no. 8, pp. 1535-1539.View/Download from: UTS OPUS or Publisher's site
Organic characterisation in rainwater was investigated in terms of dissolved organic carbon (DOC) and molecular weight distribution (MWD) after powdered activated carbon (PAC) adsorption. PAC adsorption was used as pretreatment to membrane filtration to
Shon, H, Vigneswaran, S, Kandasamy, JK & Shim, WG 2008, 'Ultraflitration Of Wastewater With Pretreatment: Evaluation of Flux Decline Models', Desalination, vol. 231, no. 1-3, pp. 332-339.View/Download from: UTS OPUS or Publisher's site
Three different mathematical models relating the flux decline were investigated to quantify the effects of pretreatment in a membrane filtration system. The models used are empirical flux decline model, series resistance flux decline model and modified series resistance flux decline model. A cross flow ultrafiltration unit was used to study flux decline and organic removal from synthetic wastewater. Flocculation and adsorption pretreatments were carried out with ferric chloride (FeCl3) and activated carbon of different doses. The three models could predict flux decline after different pretreatments and could be used as a pretreatment index to ultrafiltration.
Areerachakul, N, Vigneswaran, S, Kandasamy, JK & Duangduen, C 2008, 'The degradation of humic substance using continuous photocatalysis systems', Separation Science And Technology, vol. 43, no. 1, pp. 93-112.View/Download from: UTS OPUS or Publisher's site
Photocatalytic oxidation is an emerging technology in water and wastewater treatment. Photocatalysis often leads to complete degradation of organic pollutants without the need for chemicals. This study investigated the degradation of humic substances in
Areerachakul, N, Vigneswaran, S, Ngo, H & Kandasamy, JK 2008, 'A continuous photocatalysis system in the degradation of herbicide', Korean Journal of Chemical Engineering, vol. 25, no. 4, pp. 663-669.View/Download from: UTS OPUS or Publisher's site
The performance of both batch and continuous photo-catalytic reactors was studied to evaluate their capabilities in removing the sulfonyl urea herbicide of metsulfuron methyl (MM). It was found in a batch reactor that the addition of a small amount of powder activated carbon (PAC) significantly increased the rate of degradation of MM. The continuous photo-catalytic system resulted in 57% of MM removal. When a small dose of activated carbon was added in the photo-catalytic system, MM removal increased to 7886% MM removal for retention times between of 5.2521 min (corresponding to withdrawal rates of 1040 mLmin-1). In this study, the pseudo first order rate constants of a continuous photo-catalytic system revealed that shorter retention times were associated with lower rate constants. Solid phase micro extraction/gas chromatography (SPME/GC) results showed that high concentrations of MM were broken down to small volatile organic compounds (VOCs) by photo-catalytic oxidation. PAC adsorbed the photo-products and increased the degradation of MM.
Chang, J, Vigneswaran, S, Kandasamy, JK & Tsai, LJ 2008, 'Effect of Pore Size and Particle Size Distribution on Granular Bed Filtration and Microfiltration', Separation Science and Technology, vol. 43, no. 7, pp. 1771-1784.View/Download from: UTS OPUS or Publisher's site
The paper reviews the effect of particle size distribution and pore size distribution on granular bed filter and crossflow microfiltration performance. The experimental results of the granular bed filter with pollen particles in suspension showed that the presence of large particles improved the filter efficiency of smaller particles in suspension. Microfiltration results with bi and tri-modal latex suspensions showed that the permeate flux and the quality were significantly affected by the particle size and its distribution, especially when the particle size was smaller than the pore size of the membrane. The mathematical model simulation results of granular bed filtration show that media pore size distribution is an important parameter of filtration for the particle removal and pressure drop across the filter
Chang, Y, Chang, J, Vigneswaran, S & Kandasamy, JK 2008, 'Pharmaceutical Wastewater Treatment by Membrane Bioreactor Process - A Case Study in Southern Taiwan', Desalination, vol. 234, no. 1-3, pp. 393-401.View/Download from: UTS OPUS or Publisher's site
A pilot-scale study of pharmaceutical wastewater treatment by a membrane bioreactor (MBR) process in southern Taiwan is presented in this paper. A 10 m3/day capacity MBR plant consisting of an aeration tank and a membrane bioreactor was installed to remove organic matter (measured in terms of chemical oxygen demand (COD)). The performance of the MBR was monitored for a period of 140 days. The removal of COD was on average over 95%. The effluent did not contain any suspended solids. During the 140 days of operation, manual cleaning was carried out twice and chemical cleaning was carried out once. A natural logarithmic evolution of the viscosity with TSS concentration was observed. The results of SEM and EDX demonstrated that the fouling on the membrane outer surface was mainly due to microorganisms and/or the sludge physiological properties. The results indicated that the MBR system has potential as a means of treating high-strength and fluctuating strength wastewater with consistent performance.
Guo, W, Vigneswaran, S, Ngo, H, Kandasamy, JK & Yoon, S 2008, 'The Role of a Membrane Performance Enhancer in a Membrane Bioreactor: a Comparison with Other Submerged Membrane Hybrid Systems', Desalination, vol. 231, no. 1-3, pp. 305-313.View/Download from: UTS OPUS or Publisher's site
Among the membrane processes, membrane bioreactor (MBR) technologies are becoming an innovative and promising option for wastewater treatment and reuse. In this study the performance of the submerged membrane bioreactor was studied with an addition of MPE50, and it was compared against a sponge submerged membrane bioreactor (SMBR) and submerged membrane adsorption bioreactor (SMABR) in terms of TOC removal, COD removal, ammonium nitrogen (NH4-H) removal, orthophosphate (PO4-P) removal, transmembrane pressure (TMP) and oxygen uptake rate. SMBR with MPE50 addition significantly improved the sustainable flux and reduced membrane fouling. The improvement was better than even in the sponge SMBR system. SMBR with MPE50 achieved a high DOC and COD removal efficiency and NH4-N removal. PO4-P removal concentration of 62% initially which increased with time to over 99% after 7 day operation. In terms of phosphorus removal the sponge SMBR system performed better. OUR measurements showed that there was more microbial activity in the SMBR with MPE50 system
Hoang, T, Vigneswaran, S, Ngo, H, Kandasamy, JK, Shim, WG, Chaudhary, DS, Gotety, BP & Peiris, P 2008, 'Performance evaluation and mathematical modelling of granular activated carbon biofiltration in wastewater treatment', Korean Journal of Chemical Engineering, vol. 25, no. 2, pp. 259-267.View/Download from: UTS OPUS or Publisher's site
Biological filtration is an effective technique for removing organic matter from wastewater. The performance of a biofilter can be influenced by a range of operational conditions. In this study the performance of biofilters was investigated for the influence of filter media depth, influent concentrations, filtrations rates and backwashing. The results show that performance of GAC filters decreased with shallower filter bed depths. In addition, the GAC performed better at lower influent concentration and lower filtration rates. The daily backwash adopted to avoid the physical clogging of the biofilter did not have any significant effect on the organic removal efficiency of the filter. The concentration, activity and characteristics of the biomass are quantified and described. A mathematical model was developed to simulate the organic removal of the GAC biofiltration system. The performance of the GAC filter under different influent organic concentration levels, filtration rates and filter bed depths was adequately simulated by the mathematical model developed for this study.
Nguyen, V, Vigneswaran, S, Ngo, H, Kandasamy, JK & Choi, H 2008, 'Arsenic removal by photo-catalysis hybrid system', Separation and Purification Technology, vol. 61, no. 1, pp. 44-50.View/Download from: UTS OPUS or Publisher's site
Arsenic is a toxic semi-metallic element that can be fatal to human health. Arsenic pollution in water is found in many parts of the world, especially in developing countries such as Bangladesh, India, Nepal, and Vietnam. Photo-oxidation experiments with titanium dioxide (TiO2) as photo-catalyst showed that photo-oxidation of As(III) to As(V) is possible within minutes. Further, TiO2 can also adsorb both As(III) and As(V) on its surface. Photo-catalysis reaction with TiO2 reduced about 98% of arsenite from water containing 500 ?g/L of arsenite. By adding nano-scale zero valent iron (nZVI) of 0.05 g/L in the photo-reactor, arsenic removal can be significantly enhanced. Further the TiO2 requirement is five times less in this photo-catalysis nZVI hybrid system. The photo-catalytic degradation processes was modeled using the first-order, second-order and LangmuirHinshelwood kinetics equations and removal rates were simulated.
Kannapiran, A, Chanan, AP, Singh, G, Tambosis, P, Jeyakumaran, JM & Kandasamy, JK 2007, 'An innovative model for sustainable cost effective management of stormwater drainage assets', Water Asset Management International, vol. 3, no. 2, pp. 4-11.View/Download from: UTS OPUS
Stormwater drainage is one of the important infrastructures of any modern urban city. A well planned, operated and maintained stormwater system should drain stormwater runoff effectively during normal periods and during floods. However, with rapidly expanding cities, unanticipated problems from changinf land usage, system overloading, pollution and deteriorating environment cause problems to stormwater assets and contribute to its failure. These issues are more problematic in larger and older cities where replacement is costly. Kogarah Council, a local government authority in Sydney, Australia, is anticipated to face many of the challenges this problem poses as it manages the urban water cycle system in an integrated manner to protect, restore and enhance the stormwater assets. The council owns a significant part of these assets that were constructed back in the 1930s.
Khiadani, MH, Kandasamy, JK & Beecham, SC 2007, 'Velocity distributions in spatially varied flow with increasing discharge', Journal Of Hydraulic Engineering-Asce, vol. 133, no. 7, pp. 721-735.View/Download from: UTS OPUS or Publisher's site
The experimental study presented in this paper explores the distribution of the mean velocities for a channel receiving spatially varied (SV) inflow from directly above the centerline of the channel via sets of nozzles. The velocity components u, 1), and
Shon, H, Vigneswaran, S, Ngo, H, Kim, JK & Kandasamy, JK 2007, 'Effect Of Flocculation As A Pretreatment To Photocatalysis In The Removal Of Organic Matter From Wastewater', Separation And Purification Technology, vol. 56, no. 3, pp. 388-391.View/Download from: UTS OPUS or Publisher's site
Effects of different flocculants (chloride-based salts and ferric and ferrous salts) and initial organic concentration of wastewater on flocculation-photocatalysis hybrid process were investigated. Titanium dioxide (TiO2) adsorption alone, flocculation a
Vigneswaran, S, Shon, H, Kandasamy, JK & Shim, WG 2007, 'Performance of Granular Activated Carbon (GAC) adsorption and biofiltration in the treatment of biologically treated sewage effluent', Separation Science and Technology, vol. 42, no. 14, pp. 3101-3116.View/Download from: UTS OPUS or Publisher's site
In this study, the performance of GAC adsorption and biofiltration systems in treating biological treated sewage effluent (BTSE) was evaluated in terms of organic removal efficiency, organic fractions, and molecular weight distribution (MW) of organic matter (OM) removed. The GAC biofilter removed 23.5% and 61% of the hydrophobic fractions and hydrophilic fractions of OM in the BTSE respectively. MW distribution studies of GAC filter and GAC adsorption revealed the following: Hydrophobic fraction of the effluent showed a peak at 345 dalton after GAC biofiltration and 256 dalton after GAC adsorption, whereas, with hydrophilic fractions, peaks at 46,178 and 345 daltons were observed after GAC biofiltration and peaks at 46,178 and 256 daltons after GAC adsorption. Transphilic fraction showed the peaks at 12,783 dalton with GAC biofiltration, and 1,463 dalton with GAC adsorption. The performance of the GAC biofilter was successfully mathematically modelled.
Areerachakul, N, Vigneswaran, S, Ngo, H & Kandasamy, JK 2007, 'Granular activated carbon (GAC) adsorption-photocatalysis hybrid system in the removal of herbicide from water', Separation And Purification Technology, vol. 55, no. 2, pp. 206-211.View/Download from: UTS OPUS or Publisher's site
The performance of the granular activated carbon (GAC) fixed bed adsorption, the continuous photocatalysis systems and a combination of the two were studied to evaluate their capabilities in removing the herbicide of metsulfuron-methyl (MM) from waste wa
Sydney, Australia, has a stormwater system that is completely separate from the sewerage system. The stormwater systems are mainly managed by the 43 local councils and most of these use OSD as a means of reducing site discharge of stormwater, thereby relieving catchment flooding. Sheas Creek is an urbanized catchment that lies within the South Sydney City Council Local Government Area. Since 1984 an OSD policy has been implemented in the Sheas Creek catchment. The associated design code, like most others in Sydney, is based on discharge from individual properties without consideration of runoff from other parts of the catchment. This design code is therefore not based on a total catchment approach. The objective of this study is to assess the effectiveness of OSD in a catchment-wide manner. More specifically, to see how existing and planned OSD affects flooding in the Sheas Creek catchment, and to test the effectiveness of the current rate of permissible site discharge (PSD). The study also looks at the effectiveness of OSD when different spatial distributions are used across a catchment. The methodology involved using a computer rainfall-runoff model, OSDSAX, which is based on the ILLUDAS model. This was configured for the Sheas Creek catchment and was calibrated to match flood level data recorded during four large storm events. The model was then adopted to investigate the impact of OSD. Various scenarios were tested to satisfy the objectives of the study. Some of the results challenge conventional wisdom and these arise from catchment-specific characteristics. The analysis shows that the perceived beneficial effects of OSD are in some cases unrealistic and that catchment modelling is required to test and quantify the actual impacts for specific catchments.
Beecham, SC, Khiadani, MH & Kandasamy, JK 2005, 'Friction factors for spatially varied flow with increasing discharge', Journal Of Hydraulic Engineering-ASCE, vol. 131, no. 9, pp. 792-799.View/Download from: UTS OPUS or Publisher's site
This paper describes an experimental investigation of how friction factors change for spatially varied flow in sloping channels receiving lateral inflow. The results are compared with those of Beij in 1934, and it is concluded that uniform flow resistanc
Khiadani, MH, Beecham, SC, Kandasamy, JK & Sivakumar, SM 2005, 'Boundary shear stress in spatially varied flow with increasing discharge', Journal Of Hydraulic Engineering-ASCE, vol. 131, no. 8, pp. 705-714.View/Download from: UTS OPUS or Publisher's site
The distribution of the wall shear stress on the bed and sidewalls of an open channel receiving lateral inflow was obtained from experimental measurements of the distribution of the velocity in the viscous sublayer using a laser doppler velocimeter. The
Peregrine, DH, Kandasamy, JK, Hager, WH & Montes, JS 1999, '"Transition to a free-surface flow at the end of a horizontal conduit"', JOURNAL OF HYDRAULIC RESEARCH, vol. 37, no. 1, pp. 136-144.View/Download from: Publisher's site
Jonasson, OJ, Kandasamy, J & Vigneswaran, S 2016, 'Stormwater treatment technology for water reuse' in Green Technologies for Sustainable Water Management, pp. 75-106.View/Download from: Publisher's site
© 2016 American Society of Civil Engineers. The most common application of stormwater reuse in Australia is for outdoor irrigation, but treated stormwater also can be used to supplement other nonpotable uses, such as flushing toilets, washing clothes, firefighting, and in cooling towers. More recently, instances have emerged where stormwater has been harvested for indirect potable reuse. The water quality criteria depend on the applications, and the treatment required to meet these standards will be affected by the source of the stormwater. The conventional technologies for treating stormwater are traditionally incorporated into a management strategy to meet stormwater quality objectives aiming to protect estuaries and streams. Conventional stormwater treatment systems commonly utilized in harvesting schemes include gross pollutant traps (GPTs), vegetated swales, sediment ponds, constructed wetlands, and biofiltration systems. Some of the high-rate stormwater treatment technologies are fiber filter, deep bed filter, membrane filtration, and membrane hybrid systems.
Kandasamy, J, Kus, B & Vigneswaran, S 2016, 'Rainwater harvesting in New South Wales, Australia' in Ngo, HH, Guo, W, Surampalli, RY & Zhang, TC (eds), Green Technologies for Sustainable Water Management, American Society of Civil Engineers, USA, pp. 35-74.View/Download from: UTS OPUS or Publisher's site
© 2016 American Society of Civil Engineers. In Australia, recent droughts and concerns about climate change have highlighted the need to manage water resources more sustainably. Rainwater harvesting has emerged as a new field of sustainable water management, which offers an alternative water supply for at least nonpotable uses. This chapter illustrates a detailed sampling on the concentration of pollutants in metropolitan rainwater tanks located at different parts of Sydney. Some rainwater tanks incorporate simple sand filtration devices to improve water quality for potable uses. Concentrated pollutants remaining after treatment and sludge can be discharged to the sewer, alleviating sludge disposal problems, and is attractive in creating a low maintenance system. It is possible to create a sustainable development with a low demand for town water and low storm water pollution export, as well as reduce storm water discharges. Some of the rainwater treatment technologies discussed include adsorption, pilot scale application, and membrane filtration.
Chanan, AP, Vigneswaran, S, Kandasamy, JK & Simmons, B 2013, 'Wastewater Management Journey - From Indus Valley Civilisation to the Twenty-First Century' in Sharma, SK & Sanghi, R (eds), Wastewater Reuse and Management, Springer, Germany, pp. 3-18.View/Download from: UTS OPUS or Publisher's site
Throughout the human existence on this planet, water and wastewater infrastructure never attracted as much public attention as it did during the second half of the nineteenth century. Following extensive debate on appropriate solutions for problems associated with hygiene and public health, options were chosen from several competing alternatives, while others foreclosed. Sociocultural impacts of these late nineteenth century decisions have lasted until the present day . The shape of our cities and centralised approach embedded within sanitary engineers mindset today owe its existence to the options selected nearly 200 years ago. The current selection of water and wastewater management options, particularly in the developing world, has the opportunity to learn from 200 years of experience. It is critical that these lessons influence the design of future wastewater management systems because undoubtedly the decisions being made today will impact on the future generations. This chapter highlights the development of wastewater management through human evolution and settlement history.
Shon, H, Phuntsho, S, Vigneswaran, S, Kandasamy, JK, Aryal, R & Jegatheesan, V 2012, 'Physical, Chemical, and Biological Characterization of Membrane Fouling' in Zhang, TC, Surampalli, RY, Vigneswaran, S, Tyagi, RD, Ong, SL & Kao, CM (eds), Membrane Technology and Environmental Applications, American Society of Civil Engineers, USA, pp. 457-497.
In this chapter, advanced characterization of membrane fouling as a diagnostic tool has been summarized to prevent membrane fouling. Physical, chemical and biological analyses as membrane autopsies are mainly utilized to better understand membrane foulant. The physical characteri zation gives structure, roughness, charge effect, strength and hydrophobicity of membrane fouling. The chemical methods provide qualitative and quantitative measurements of different inorganic and organic matter. The biological properties present the spatial biofilm distribution, structure of dominant microorgnisms and isolation and identification of microorganisms. In addition, detailed membrane foulant types are reviewed in terms of structure, roughness, hydrophobicity, charge effect, strength, calcium, magnesium, alluminum, iron, silicate, particle, functional group, biopolymer, humic acid, polysaccharide, structural composition, biofilm structure, microorganism and foulant interaction.
Vigneswaran, S, Sathananthan, S, Shon, HK, Kandasamy, J & Visvanathan, C 2012, 'Delineation of membrane processes' in Membrane Technology and Environmental Applications, American Society of Civil Engineers, pp. 41-74.View/Download from: UTS OPUS or Publisher's site
Johir, MA, Singh, G, Kandasamy, J, Vigneswaran, S, Kus, B & Naidu, R 2012, 'Stormwater Harvesting and Reuse' in Meyers, RA (ed), Encyclopedia of Sustainability Science and Technology, Springer, Germany, pp. 111095-10117.View/Download from: Publisher's site
Rapid urbanization has contributed to considerable increases in urban stromwater runoff and pollution, a deterioration of the water quality of urban waterways , and significant threats to its ecosystem. Stormwater runoff is the most neglected resource and, given that it contributes significantly to diffuse pollution of our waterways, it needs to be managed in more sustainable way to capture its benefits and at the same time to reduce the adverse impacts on waterways and receiving waters. A cultural change is occurring in urban stormwater management practice. Environmental aspects are becoming a major focus, with potentially profound effects on the traditional approach to stormwater management. An integrated approach to stormwater treatment and management and stormwater harvesting regards stormwater as a resource rather than a waste and considers all aspects of runoff within a development, including implementation of water quality/quantity controls, maximizing water reuse/conservation whilst preserving the amenity and environmental values within the catchment. Stormwater harvesting and reuse offers a potential alternative water supply for at least non-potable uses. The benefits of a successful stormwater harvesting systems include reductions in stormwater pollution loads to downstream waterways and estuaries, and in stormwater volumes and discharges. Methods of assessment to check the extent to which stormwater treatment systems are meeting their design objectives and compliance to water quality standards is important.
Vigneswaran, S, Khorshed, C, Kandasamy, J & Kim, SH 2012, 'Membrane processes for desalination: Importance of pre-treatment to reduce organic fouling' in Membrane Technology and Environmental Applications, American Society of Civil Engineers, pp. 276-297.View/Download from: UTS OPUS or Publisher's site
Vigneswaran, S, Nguyen, TV, Kandasamy, J, Ben Aim, R & Visvanathan, C 2012, 'Membrane processes for drinking water treatment' in Membrane Technology and Environmental Applications, ASCE Publications, pp. 140-168.View/Download from: UTS OPUS or Publisher's site
This volume provides in-depth technical information on the fundamentals, applications, and recent advances of membrane technology, including state-of-the-art reviews of current research, critical analysis of new processes and materials, and ...
Johir, MA, Orem, Y, Messalem, R, Ben-David, E, Herzberg, M, Kushmaro, A, Ji, X, Di Profio, G, Curcio, E, Drioli, E, Laroche, JF, Remize, P, Leparc, J, Vigneswaran, S, Chinu, KJ, Lee, J, Shon, H, Kandasamy, JK, Ye, Y, Sim, LN, Herulah, B, Chen, V, Fane, AC, Tansakul, C, Laborie, S & Cabassud, C 2011, 'Evaluation and comparison of seawater and brackish water pre-treatment' in Drioli, E, Criscuoli, A & Macedonio, F (eds), Membrane-Based Desalination: An Integrated Approach (MEDINA), IWA Publishing, UK, pp. 33-70.View/Download from: UTS OPUS
Membrane technology has been increasingly applied in water and wastewater treatment. Membrane
filtration involves separation of dissolved, colloidal, and particulate constituents from a pressurized
fluid using microporous materials. Membranes are categorized into four main groups based on
the size of their pores, namely, reverse osmosis (RO), nanofiltration (NF), ultrafiltration (UF), and
Microfiltration with the largest pore size of 0.1–10 μm is commonly used to separate suspended
particulates, large colloids, and bacteria; hence, it is suitable for the treatment of water that has high
turbidity and low color or organics content (Schafer, 2001). Similarly, ultrafiltration (0.001–0.1 μm)
can exclude macromolecules and fine colloidal suspensions such as proteins, dyes, and bacteria, but
the removal of dissolved organics is limited. MF and UF can also be used as pretreatment for NF
and RO processes (Schafer, 2001).
Nanofiltration with smaller pore sizes of between 15 and 30 Å is employed for water softening
and the removal of disinfection by-products (DBPs). NF can reduce 60%–80% of the hardness and
more than 90% of color-causing substances (Cheryan, 1998).
In order for constructed wetlands to perform at their optimal level, they must be managed and maintained efficiently. An operation and maintenance plan is therefore essential to ensure that the wetland is performing at its optimum level. Constructed wetlands go through different phases throughout their working life. These phases include commissioning, operation, and fmally refitting and decommissioning. With each of these phases comes a unique set of operation and maintenance needs. Operation and maintenance plans provide necessary information for management to he able to successfully control and operate a constructed wetland. Operation and maintenance plans must contain essential elements in order for them to be of assistance to operators. There are four vital sections in the plan, which include a description of the wetland, management activities, a management calendar, and a list of emergency contacts. Monitoring is vital for the operation of a successful wetland, and is a key component of an operation and maintenance plan. Monitoring helps determine if the wetland is performing as desired, and will aid in identifying any problems. The data obtained from monitoring can then be used to progress treatment and performance, resulting in a more proficient wetland.
idris, E, Chanan, AP & Kandasamy, JK 2008, 'Socio-Economics of Constructed Wetlands: Engaging the Community' in Kandasamy, J & Vigneswaran, S (eds), Constructed Wetlands, Nova Science Publishers, Inc., New York, USA, pp. 101-124.
Although good engineering design of a constructed wetland is a significant contributor to the success of its operation, a major element that is often taken for granted is the local community. This paper highlights the social and economic benefits associated with constructed wetlands, and relates these benefits to the necessity to engage the community. Conununily involvement in fact is required at every stage of a constructed wetland project. The paper outlines the methods that can be used to plan for effective community involvement for such projects, and provides a summary of tools and techniques that can be employed at different stages. A case study of Moore Reserve Constructed Wetland Project, in New South Wales, Australia is provided as an example where successfUl community engagement delivered a wetland that fulfilled communityâs expectations.
Phuntsho, S, Shon, HK, Vigneswaran, S & Kandasamy, J 2008, 'Wastewater Stablisation Ponds (WSP) For Wastewater Treatment' in Vigneswaran, S (ed), Water and Wastewater Treatment Technologies, UNESCO & Encyclopedia of Life Support Systems (EOLSS).
Many industrialised countries have achieve d high levels of wastewater treatment technologies most of which are too mechanized and automated and beyond the affordability of the poor and developing nations. Technologies that are appropriate to the developing nations are required since two third of world’s population live in developing countries.
This review focuses mainly on those technologies appropriate to the developing countries. Appropriate technology should be affordable (capital cost), have low O&M cost (sustainability), effective in meeting the discharge standards, at least nuisance (public acceptability) and is environment-friendly.
Many low cost technologies are being developed but the choice of the most appropriate technology depends on a proper evaluation of all the factors such as economic, political, social, availability, etc. Wastewater Stabilization Ponds (WSP) have been extensively used worldwide because of the simplicity in design and construction, the low capital and operating cost, are very reliable and are a sustainable technology.
Constructed wetlands not only treat wastewater but have other functions such as habitats for animals and birds, recreational areas for the visitors, etc. Other low cost technologies appropriate to developing countries such as land treatments, filtration techniques, attach growth, aeration, baffled reactor and chemically enhance primary treatment are also discussed.
Shon, HK, Phuntsho, S, Vigneswaran, S & Kandasamy, J 2008, 'Physico-Chemical Processes for Organic Removal from Wastewater Effluent' in Vigneswaran, S (ed), Water and Wastewater Treatment Technologies, UNESCO & Encyclopedia of Life Support Systems (EOLSS).
This chapter covers physio-chemical processes including advanced oxidation processes for wastewater treatment. The approach used in this chapter is to first provide a brief introduction to each of the processes followed by a brief description of the process fundamentals in removing organic matter. The removal of effluent organic matter (EfOM) in terms of dissolved organic car bon (DOC), molecular weight distribution (MWD) for each process is then explained followed by removal of endocrine disrupting chemicals (EDCs) and pharmaceutical and personal care products (PPCPs) by each process.
Moat, G, Simpson, B, Ghanem, P, Kandasamy, JK & Vigneswaran, S 2008, 'Constructed Wetlands: Classification, Functions and Treatment' in Kandasamy, J & Vigneswaran, S (eds), Constructed Wetlands, Nova Science Publisher, Inc., New York, USA, pp. 1-26.
Constructed wetland technology utilises natural processes to treat wastewater and stormwater. Wetland technologies can provide cheap and effective wastewater treatment in both temperate and tropical climates, and is suitable for the adoption in both industrialised as well as developing nations. Constructed wetlands are being utilised for the removal of a range of pollutants and a broad range of wastewaters worldwide. This chapter provides a comprehensive review of the classifications, functions and treatment processes of constructed wetland.
Nguyet, LM, Kandasamy, J & Minh, DQ 2019, 'Assessing the Impact of Inundation Preventing Construction on River Morphology of Can Giuoc River in Long An Province', IOP Conference Series: Earth and Environmental Science.View/Download from: UTS OPUS or Publisher's site
© 2019 IOP Publishing Ltd. All rights reserved. To attend to inundation prevention in Ho Chi Minh city, the Prime Minister approved the irrigation plan to prevent inundation in which there is a solution of constructing Thu Bo tidal drainage in Long An province. Thu Bo drainage is expected to have a total width of 200m, including 120m with drainage threshold -8m and 80m with drainage threshold -4,0m. Thu Bo drainage will be constructed on Can Giuoc River which is a national waterway that has been planned (two level 3 waterways from Ho Chi Minh city to Kien Luong and to Ca Mau). The article presents the result of MIKE 21 model study to assess the impact of inundation preventing construction on river morphology of Can Giuoc River in Long An province. The result indicates that the location of the drainage has caused local erosion due to narrow riverbed, flow velocity here increases, hence there are erosions in front of and behind the drainage. The sphere of erosion influence causes riverbed modification towards the upstream and downstream about 180 - 200m, especially in the time of drainage operation, there are significant differences between the upstream and downstream water level, which causes local erosion, therefore it is essential to have riverbed and river bank strengthening reinforcement measures to stabilize riverbed.
Shanmuganathan, S, Johir, MAH, Listowski, A, Vigneswaran, S & Kandasamy, J 2015, 'Sustainable Processes for Treatment of Waste Water Reverse Osmosis Concentrate to achieve Zero Waste Discharge: A Detailed Study in Water Reclamation Plant', Waste Management for Resource Utilisation (Procedia Environmental Sciences), International Conference on Solid Waste Management, Elsevier, Bengaluru, India, pp. 930-937.View/Download from: UTS OPUS or Publisher's site
Water reclamation systems based on dense membrane treatment such as reverse osmosis (RO) are being progressively applied to meet water quantity and quality requirements for a range of urban and environmental applications. The RO concentrate usually represents 25% of the feed water flow and contains the organic and inorganic contaminants at higher concentrations. The amount of RO concentrate waste water requiring disposal must be as minimal as possible (near zero-discharge); the recovery of high quality water should be as high as possible. Management issues related to proper treatment and disposal of RO concentrate are an important aspect of sustainable water reclamation practice. The RO concentrate is a significant component of water treatment process and poorly managed treatment and disposal of RO concentrate causes significant consequences. Even in a small to medium size water reclamation plant in Sydney, 2000 kL of water is treated by RO and around 300 kL of RO concentrate is produced daily. This RO concentrate consists of a high level of organics (25-30mg/L of DOC which is mainly refractory organics) and inorganic salts (Cl− = 400-650mg/L, Na+ = 400-500mg/L, Ca2+ = 93-200mg/L, K+ = 63-100mg/L). The RO concentrate waste disposal cost can be minimized and made valuable by reclaiming the RO concentrate with the aim of producing salts from the solutes and recycling the water to the treatment system. Technologies for recovery of high salt concentration from the RO concentrate such as forward osmosis (FO) and membrane distillation (MD) are either energy intensive or not developed in large scale. In this study, we highlight a sustainable membrane adsorption hybrid system in treating this RO concentrate.
Nguyen, TC, Loganathan, P, Nguyen, TV & Kandasamy, J 2014, 'Simultaneous adsorption of heavy metals by a natural Australian iron coated zeolite', The 7th International IWA Young Water Professionals, Taipei, Taiwan.
Iron coated zeolite was synthesized by adding natural zeolite in an iron nitrate solution under strongly basic condition. According to heavy metals adsorption experiments, carried out after the synthesis and characterization procedures, the ICZ is a promising new material since it adsorbs significantly larger heavy metal concentrations than zeolite. This fact is owed to its high specific surface area and high negative surface charge. The adsorption kinetic results were fitted well by the Langmuir model. The adsorption capacity predicted by the Thomas model was also highest (5.4-12.5mg/g) for the experimental conditions. Batch and fixed-column experimental results showed that zeolite is a potential adsorbent for removing heavy metals from aqueous solutions. The batch adsorption was satisfactorily explained using the Langmuir isotherm while the column adsorption data fitted reasonably well to the empirical Thomas model; the highest adsorption capacity was found with Pb to be 5.33 mg/g at the inlet concentration of 5 mg/L, 25 cm bed height and 5 m/h filtration velocity.
Ben-Aim, R, Chinu, KJ, Johir, MH, Vigneswaran, S & Kandasamy, JK 2010, 'New sources of water: Optimizing the use of membranes for their production', IWA Regional Conference and Exhibition on Membrane Technology & Water Reuse, IWA, Istabul-Turkey, pp. 1025-1027.
In many parts of the world water stress is predicted to occur in a near future. Membrane technology can help address this issue but the use of membranes has to be optimized for obtaining suitable water quality in an acceptable economic and ecological manner. Eventually the use of membranes could introduce a shift from a centralized water management to a decentralized one. The three potential new sources of water are treated wastewater or wastewater reuse, seawater and brackish water, rainwater including stormwater.
Hannan, JM & Kandasamy, JK 2008, 'Experience of 1D and 2D flood modelling in Australia - a guide to model selection based on channel and floodplain characteristics', Flood Risk Management: Research and Practice - Proceedings of the European Conference, European Conference on Flood Risk Management: Research and Practice, CRC Press - Taylor & Francis Group, Oxford, UK, pp. 273-280.View/Download from: UTS OPUS or Publisher's site
The average annual cost of flooding in Australia is $318 million per year (BTE, 2001). Some 100 flood studies, floodplain management studies and plans are currently being undertaken in Australia to seek to reduce the potential flood risk to residents and properties in flood-affected areas. Consequently, a great body of knowledge and experience in flood modelling practices has been acquired, from one-dimensional (1D) steady-state models through to two-dimensional (2D) finite element hydrodynamic models. This paper critically appraises 1D and 2D hydraulic modelling techniques based on a quantitative comparison of MIKE-11, HEC-RAS and RMA-2 modelling results for a creek system in Australia. Based on the findings of the case study, the paper provides practical guidance for modellers on the suitability of 1D and 2D modelling for common physical channel and floodplain characteristics.
Chanan, AP, ghetti, I & Kandasamy, JK 2008, 'From El Nino to La Nina and Back: Challenges of managing coastal areas through climate change', IWA World Water Congress 2008, Vienna, Austria, IWA World Water Congress, IWA Publishing, Vienna, Austria, pp. 113-114.
In Australia (particularly eastern Australia), La Niña events are associated with increased probability of wetter conditions, whereas El Niño events are associated with an increased probability of drier conditions For an urbanised coastal council like Kogarah there are a number of impacts associated with climate change. For instance, the risk of flood may be increased due to more intense rainfalls, when couple with rising sea levels. Coastal Councils may also experience increased coastal flooding and coastal erosion due to increased storm surges and rising sea levels. Water restrictions are already in place due to severe droughts and it is further predicted that councils will have limited water supply available for irrigation needed to provide parks and well-maintained sporting facilities for the community. Given that the science of climate change is not an exact science there are obvious technical and socio-political challenges that are to be addressed. The paper shares Kogarah Councils experiences in dealing with these challenges and provides a snapshot of programs currently being implemented in response to climate change. By investing in proactive measure to reduce risk and vulnerability it is possible to build a powerful resilience to climate change.
Chanan, AP, Kandasamy, JK & Sharma, D 2008, 'A Role for Input-Output Analysis in Urban Water Policy Decisions in Australia', Input - Output & Environment Website, Input - Output & Environment, IIOA, Saville Spain, pp. 1-18.
Discussion on water reuse and its role in sustainable water resource management in Australia has been on the agenda of policy makers and scientific community for the last three decades. Despite that, promulgation of water reuse especially in metropolitan Australia has been a rather slow process. To advance sustainable urban water management, water policy shift towards `co-management and `higher value use is critical. Input Output Analysis provides an ideal mechanism for water policy makers to prepare a case for this much needed policy shift. The paper discusses the methodology available for such an exercise, with special reference to Kogarah Local Government Area, located within the Sydney Metropolitan.
Kannapiran, A, Chanan, AP, Singh, G, Tambosis, P, Jeyakumaran, JM & Kandasamy, JK 2008, 'Strategic asset management planning of stormwater drainage systems', Proceedings of the IWA World Water Congress and Exhibition 2008, IWA World Water Congress, International Water Association (IWA), Vienna, Austria, pp. 1-8.
Management of the urban water cycle in an integrated manner is an essential task to protect, restore and enhance in a sustainable manner. Strategic asset management planing is being developed as local government authorities face many challenges associated with managing the urban water cycle system. Statistical or conventional mathematical modelling approach has been found not practical for assessment of deteriorating infrastructures. Alternatively, application of fuzzy-based models is found more suitable as it links engineering judgment, experience and scarce field data of the deteriorating assets. In this study, a representative network of buried stormwater system s data is drawn and a pipe condition index is derived by linking the field data and reasoning using fuzzy approach. The inferred results are found to be useful and relevant for asset maintenance and future development programs.
Ho, DP, Vigneswaran, S, Ngo, H, Shon, H & Kandasamy, JK 2008, 'Adsorption and Photocatalysis Kinetics of UV Light Responsive and Visible Light Responsive Titanium Dioxide in Wastewater Treatment', Proceedings of the IWA World Water Congress and Exhibition 2008, IWA World Water Congress, International Water Association (IWA), Vienna, Austria, pp. 1-8.
The possible use of photocatalysis with TiO2 in wastewater treatment has been the focus of numerous studies in recent years. In this study, the adsorption and photocatalytic oxidation of organic compounds by UV light responsive titanium dioxide (P25) and visible light responsive titanium dioxide (Vis-TiO2) were investigated. Firstly, the adsorption behavior of the two photocatalysts was examined by the adsorption isotherm and kinetics experiments. The photocatalytic reactivity of the catalysts was then compared at different operating conditions. The results indicate that Freundlich model well described the adsorption capacity of both materials. The photocatalytic kinetics showed that the highest removal of NOM was achieved at an optimum concentration of 1.0 g/L of both photocatalysts. In case of P25, one-hour irradiation of UV light at the intensity of 184.64 mW/cm2 resulted in approximately 57% of TOC removal. It was observed that visible light photoexciting Vis- TiO2 required a longer irradiation time of 2 days to remove 65% of organic matters.
Mohammed Abdul, J, Areerachakul, N, Shon, H, Vigneswaran, S & Kandasamy, JK 2008, 'Biofilter and Photo-Catalytic Treatment Processes of Groundwater Contaminated with Landfill Leachate', Proceedings of the IWA World Water Congress and Exhibition 2008, IWA World Water Congress, International Water Association (IWA), Vienna, Austria, pp. 1-8.
Landfill leachate is produced when rainwater infiltrates into the landfill and permeates through the decomposing waste within the landfill leaching out with it contaminants and pollutants. Untreated leachates can permeate ground water or mix with surface waters and contribute to the pollution of soil, ground water, and surface water. In this study, the processes such as GAC bio-filtration and photocatalysis and bio-filter were evaluated in treating synthetic landfill leachate. The Total organic carbon (TOC) removal efficiency (of landfill leachate) was evaluated by sequential adsorption/bio-sorption (on GAC) and compared with photocatalysis. GAC bio-filtration led to a consistent TOC removal even after a long period of operation without the need to regenerate the activated carbon. Even after 35 days of continuous running, the TOC of the effluent from the GAC bio-filter was approximately 60% of the influent quality (i.e. 40% removal). Biofiltration with a post treatment of advanced oxidation with Fenton reagent led to more 70% of removal of TOC. Also, the treatment of biofilter redcued significantly the concentration of Fenton reagent. On the other hand photocatalysis with TiO2 as a separate treatment led to only 40% TOC reduction.
Kandasamy, JK & Vigneswaran, S 2006, 'Constructed Wetlands for Wastewater and Stormwater Management', Current Issues on Wetland Conservation in Asia: In View of the Upcoming COP10, International Symposium on Regional Wetlands Issues In Asia, Daewoong, Bugok, South Korea, pp. 60-70.
Kannapiran, A, Jeyakumaran, JM, Chanan, AP, Kandasamy, JK, Singh, G, Tambosis, P & Al-Jumaily, A 2007, 'Asset Management of Stormwater System using Fuzzy Logic', The Eighth International Conference on Intelligent Technologies (InTech-07), International Conference on Intelligent Technologies, University of Technology, Sydney, Sydney, Australia, pp. 182-188.View/Download from: UTS OPUS
Sundravadivivel, M, Kandasamy, JK & Vigneswaran, S 2006, 'Policy and Design Issues in Rainwater Harvesting: Case Study in South Asia', Rainwater Harvesting and Management Vision: Multipurpose and Proactive - Workshop of IWA World Water Congress, IWA World Water Congress, IWA, Beijing, China, pp. 69-78.View/Download from: UTS OPUS
Visvanathan, C, Kandasamy, JK & Vigneswaran, S 2006, 'Rainwater Collection and Storage in Thailand: Design, Practices and Operation', Rainwater Harvesting and Management Vision: Multipurpose and Proactive - Wortkshop of the IWA World Water Congress, IWA World Water Congress, IWA, Beijing, China, pp. 69-78.View/Download from: UTS OPUS
McLean, JT, Beecham, SC & Kandasamy, JK 2003, 'Field Assessment of Local Scour at Bridge Sites', 28th International Hydrology and Water Resources Symposium, Hydrology and Water Resources Symposium, Engineers Australia, Wollongong, Australia, pp. 1-8.View/Download from: UTS OPUS
McLean, JT, Beecham, SC & Kandasamy, JK 2003, 'Field Assessment of Local Scour at Bridge Sites', Proc. 2003 International Hydrology and Water Resources Symposium, Hydrology and Water Resources Symposium, Engineers Australia, Wollongong, pp. 115-122.View/Download from: UTS OPUS
Dierkes, C, Kuhlmann, L, Kandasamy, J & Angelis, G 2002, 'Pollution retention capability and maintenance of permeable pavements', Global Solutions for Urban Drainage, pp. 1-13.
Permeable pavements of concrete paving-stones for rainwater infiltration are established as a sustainable method for the drainage of traffic areas and for pollutant source control. Various systems for different applications exist. Pollutants like heavy metals and hydrocarbons in the runoff can endanger soil and groundwater, when the they are not sufficiently removed during infiltration. Clogging and the decrease of infiltration capacity are problems that must be considered if permeable pavements are demanded to be used as an alternative to traditional drainage systems. In this study the pollution retention capacity of different permeable road constructions is assessed in the laboratory and in field investigations. A new cleaning device to recover the infiltration capacity was developed, that ensures a lifetime operation of the investigated pavements. With special designed concrete pavers a sufficient protection of soil and groundwater can be achieved. The use of permeable pavements is sustainable, if planning, construction supervision and maintenance are carded out according to the latest research results.
Kandasamy, J & Beecham, S 2002, 'Experience of flood modeling in NSW, Australia', Global Solutions for Urban Drainage, pp. 1-11.
The average annual cost of flooding in Australia is $AUD314 million per year (BTE 2001). Flooding most severely affects the state of New South Wales (NSW) where 40% of the nation's flood damage occurs. The NSW Floodplain Management Program implements the NSW State Government's flood policy and seeks to ensure that the flood damages to existing developments are reduced, that future development occurs in a manner compatible with the flood risk and that the management of major rare floods (eg levee overtopping) is addressed in emergency response planning. Central to the process of defining the flood risk is numerical modelling and many flood studies have been carried out throughout New South Wales under the floodplain management program in the last 20 years. Five cases that demonstrate the more recent experience gained from some of the studies are presented in this paper.