Dr. Rupak Aryal has been working as a Postdoctoral Research Fellow with part-time teaching. Dr. Aryal's research focuses on the innovative water and wastewater treatment and reuse technologies for last 10 years as a leading researcher in different universities in different parts of the world (University of Tokyo, Japan; Kathmandu University, Nepal; University of Ulsan, South Korea). His expertise and practical experience cover a wide range of disciplines in water and wastewater science and engineering.Dr. Aryal has strong knowledge and experience in water quality and quantity issues such as rainfall runoff relationship, modeling urban runoff, pollutants deposition and transport in water environment including drainage systems, treatment practices in pollutants removal using novel geo and synthetic materials.In wastewater, Dr. Aryal has been focusing in wastewater treatment using membrane technology. His main aim is to minimize/mitigate fouling. Dr. Aryal has been using two different approaches for fouling mitigation: physical approach and biomass alteration approach. In both approaches he has been utilizing his strong theoretical, mathematical and analytical skills. He has been developing particle deposition phenomenon with respect to particle sizes and operating parameters.His work in physical parameters alteration includes changing of biomass floc size, change of aeration in reactor and changing of hydraulic and sludge retention time.In biomass alteration, Dr. Aryal has been working with different pretreatment process (adsorption, flocculation) that affects the chemistry of biomass. He has also been using biomass quenching techniques to identify the role of microbes in membrane fouling and its influence in effluent quality. For the last five years, he has published more than 24 peer reviewed papers in several prestigious journals (such as Water Research, Separation and Purification Technology, Water Science and Technology and Urban Water) and published more than 40 conferences proceedings.Dr Aryal has received prestigious research funds from Japan Science and Technolgy (Government of Japan), Brain Korea 21 (Government of South Korea); Kurita Water Foundation, Japan, University Grant Commission Nepal etc. In UTS he has been actively involved in different project.
Member of International Water Association (IWA) & Royal Australian Chemical Institue Inc (RACI)
- Stormwater emerging contaminants in urban and ultra-urban environment and their treatment
- Urban catchment: rainfall-runoff response
- Physico-chemical characteristics of soil and its role in speciation and mobility of contaminants.
- Micro and macromolecular chemistry behind fouling in membrane bioreactor
- Supported biomass membrane bioreactor: optimization of aeration for better fouling control.
- Role of ultra and fine particles in mobilizing hazardous pollutants in urban environment.
- Atmospheric contaminant transport in coastal region.
Stormwater and pollutants transport
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
Yadav, MK, Aryal, R, Short, MD & Saint, CP 2019, 'Fluorescence Excitation-Emission Spectroscopy: An Analytical Technique to Monitor Drugs of Addiction in Wastewater', WATER, vol. 11, no. 2.View/Download from: UTS OPUS or Publisher's site
Yadav, MK, Short, MD, Gerber, C, van Den Akker, B, Aryal, R & Saint, CP 2019, 'Occurrence, removal and environmental risk of markers of five drugs of abuse in urban wastewater systems in South Australia', Environmental Science and Pollution Research, pp. 1-11.View/Download from: Publisher's site
© 2018 Springer-Verlag GmbH Germany, part of Springer Nature The occurrence and fate of five drugs of abuse in raw influent and treated effluent wastewater were investigated over a period of 1 year in the Adelaide region of South Australia. Four wastewater treatment plants were chosen for this study and monitored for five drugs which included cocaine in the form of its metabolite benzoylecgonine (BE), methamphetamine, 3,4-methylenedioxymethamphetamine (MDMA) and two opioids (codeine and morphine) during the period April 2016 to February 2017. Alongside concentrations in raw sewage, the levels of drugs in the treated effluent were assessed and removal efficiencies were calculated. Drug concentrations were measured by mixed-mode solid phase extraction and liquid chromatography coupled to a quadrupole mass spectrometer. Drug concentrations detected in the raw wastewater ranged from 7 to 6510 ng/L and < LOD to 4264 ng/L in treated effluent samples. Drug removal rates varied seasonally and spatially. The mass loads of drugs discharged into the environment were in descending order: codeine > methamphetamine > morphine > MDMA > BE. Results showed that all the targeted drugs were on average incompletely removed by wastewater treatment, with removal performance highest for morphine (94%) and lowest for MDMA (58%). A screening-level environmental risk assessment was subsequently performed for the drugs based on effluent wastewater concentrations. Based on calculated risk quotients, overall environmental risk for these compounds appears low, with codeine and methamphetamine likely to pose the greatest potential risk to receiving environments. Given the recognised limitations of current ecotoxicological models and risk assessment methods for these and other pharmaceutical drugs, the potential for environmental impacts associated with the continuous discharge of these compounds in wastewater effluents should not be overlooked.
Aryal, R, Kafley, D, Beecham, S & Morawska, L 2018, 'Air quality in the Sydney metropolitan region during the 2013 blue mountains wildfire', Aerosol and Air Quality Research, vol. 18, no. 9, pp. 2420-2432.View/Download from: UTS OPUS or Publisher's site
© Taiwan Association for Aerosol Research. Australia commonly experiences extensive wildfires, mostly during its hot dry summers. These often lead to a significant loss of life and property. The October 2013 Blue Mountains Fire burnt through more than 100,000 hectares and generated a large amount of fire dust that was transported to the downwind community residing in the Sydney metropolitan area, which is the largest city in Australia. Record-breaking temperatures in New South Wales and strong winds worsened the wildfire danger index, and the extensive fires that broke out by 17th October lasted for more than a week. Analysis of the particulate matter monitored by the New South Wales Environmental Protection Authority around the fire zone showed that the concentrations of PM10 and PM2.5 increased by more than twofold (> 200%) and remained high for a week. During the peak fire period, SOx, NOx and O3 concentrations increased by 52%, 29% and 42%, respectively, above the usual levels recorded in metropolitan Sydney. The increase in the concentrations of these air contaminants in the Sydney metropolitan region over such an extended period may have caused increased human health risks, which are also examined in this paper.
Hussain, S, van Leeuwen, J, Aryal, R, Sarkar, B, Chow, CWK & Beecham, S 2018, 'Removal of organic matter from reservoir water: mechanisms underpinning surface chemistry of natural adsorbents', International Journal of Environmental Science and Technology, vol. 15, no. 4, pp. 847-862.View/Download from: UTS OPUS or Publisher's site
© 2017, Islamic Azad University (IAU). One of the key challenges in water treatment industry is the removal of organic compounds by cost-effective methods. This study evaluated the adsorptive removal of dissolved organic carbon (DOC) from reservoir water using fuller's earth (FE) in comparison with natural (SQ) and modified quartz (MSQ) sands. The removal capacities of FE at different contact times, pH levels, adsorbent dosages and initial DOC concentrations were compared with both the quartz sands. The optimum DOC removals by FE and SQs were achieved at contact time of 60 and 30 min, pH level of 6 and 4, and at adsorbent dose of 1.5 g/150 mL and 10 g/100 mL, respectively. The adsorption capacity of FE (1.05 mg/g) was much higher compared to the MSQ (0.04 mg/g) and SQ (0.01 mg/g). Adsorption equilibrium data better fitted to the Freundlich model than to the Langmuir model, suggesting that adsorption occurred primarily through multilayer formation onto the surfaces of FE and SQ. The pseudo-second-order model described the uptake kinetics more effectively than the pseudo-first-order and intra-particle diffusion models, indicating that the mechanism was primarily governed by chemisorption. These observations were well supported by the physiochemical characteristics and charge behaviour of the adsorbents. In mass-transfer study, the results of liquid film diffusion model showed that the adsorption of DOC on FE was not controlled by film diffusion, but other mechanisms also played an essential role. This study demonstrates that FE is an effective adsorbent for the removal of DOC in surface water treatment.
Moradi, S, Sawade, E, Aryal, R, W.K. Chow, C, van Leeuwen, J, Drikas, M, Cook, D & Amal, R 2018, 'Tracking changes in organic matter during nitrification using fluorescence excitation–emission matrix spectroscopy coupled with parallel factor analysis (FEEM/PARAFAC)', Journal of Environmental Chemical Engineering, vol. 6, no. 1, pp. 1522-1528.View/Download from: UTS OPUS or Publisher's site
© 2018 Elsevier Ltd Fluorescence excitation-emission matrix spectroscopy coupled with parallel factor analysis (FEEM/PARAFAC) was applied to characterise natural organic matter (NOM) present in nitrified and non-nitrified waters from different sampling sites in a drinking water distribution system in Australia. Each excitation-emission matrix (EEM) data set of nitrified and non-nitrified water samples were successfully decomposed into a three component PARAFAC model (C-1, C-2, and C-3). The spectral shapes of these components were compared with those identified earlier in other studies from the OpenFluor database. While C-1 and C-2 exhibited similar fluorescence spectra in both non-nitrified and nitrified sampling locations, there were some fluorescence peaks in C-3 for nitrified water samples that were not present in non-nitrified water samples. Both C-1 and C-2 in each PARAFAC model for nitrified and non-nitrified water samples showed striking similarities with components previously listed as humic-like compounds. While C-3 for non-nitrified water samples also consisted of terrestrial humic-like compounds, C-3 in PARAFAC model for nitrified water samples represented protein-like material produced as a result of microbiological activity. The fluorescence peaks that appeared only in nitrified sampling locations are related to the formation of microbial-like compounds associated with nitrification. These results indicate that PARAFAC modelling of EEM data can be used to investigate nitrification and water quality changes in chloraminated drinking water distribution systems.
Nirola, R, Biswas, B, Megharaj, M, Subramanian, A, Thavamani, P, Aryal, R & Saint, C 2018, 'Assessment of chromium hyper-accumulative behaviour using biochemical analytical techniques of greenhouse cultivated Sonchus asper on tannery waste dump site soils.', Environmental Science and Pollution Research, vol. 25, no. 27, pp. 26992-26999.View/Download from: UTS OPUS or Publisher's site
Keeping the sources of pollution such as chromium (Cr) under a safe limit is a daunting challenge due to the negative impact of heavy metal bioaccumulation in vegetation and the concomitant human health exposure. We took a closer look at Sonchus asper by cultivating in the green house. It resulted in 80% germination when cultivated over nine different soils collected from the tannery dump site. The biochemical analytical techniques such as mass spectrometry indicated significant bioaccumulation of Cr in the plant tissue. As per the ICP-MS analysis, this annual herb resulted in the accumulation of 601 mg kg-1 of total Cr with 212 mg kg-1 in its shoot from soil samples containing up to 41 mg kg-1 of hexavalent Cr. The energy dispersive X-ray (EDX) spectroscopy of S. asper revealed a higher level of S element indicating a sulfate-Cr binding relation. Elevated content of Cr in soil (73,721 ± 65 mg kg-1) caused biochemical changes in the shoot of S. asper as indicated by the disappearance of Fourier transform infrared spectroscopy (FTIR) bands at 935 and 872 cm-1 and further revealing aliphatic -CH2 appearing as anti-symmetry νa(CH2) and symmetric vibration νs(CH2) at the band of 2920 and 2850 cm-1, respectively.
Nirola, R, Megharaj, M, Subramanian, A, Thavamani, P, Ramadass, K, Aryal, R & Saint, C 2018, 'Analysis of chromium status in the revegetated flora of a tannery waste site and microcosm studies using earthworm E. fetida', Environmental Science and Pollution Research, vol. 25, no. 6, pp. 5063-5070.View/Download from: UTS OPUS or Publisher's site
© 2017, Springer-Verlag GmbH Germany. Chromium from tannery waste dump site causes significant environmental pollution affecting surrounding flora and fauna. The primary aims of this study were to survey vegetation, investigate the degree of soil pollution occurring near tannery waste dump site and make a systematic evaluation of soil contamination based on the chromium levels found in plants and earthworms from the impacted areas. This paper presents the pollution load of toxic heavy metals, and especially chromium, in 10 soil samples and 12 species of plants. Soil samples were analysed for heavy metals by using ICP-MS/ICP-OES method. Results indicated that Cr in soils exceeded soil quality guideline limits (SQGL). The total chromium present in the above ground parts of plants ranged from 1.7 mg kg−1 in Casuarina sp. to 1007 mg kg−1 in Sonchus asper. The Cr bioaccumulation in Eisenia fetida from tannery waste soil ranged from 5 to 194 mg kg−1. The high enrichment factor of Cr in S. asper and bioaccumulation factor in earthworms indicate that there is a steady increase of toxic chromium risk in this area, which could be correlated with the past dumping activity. Emphasis needs to be put on control measures of pollution and remediation techniques in such areas to achieve an ecologically sustainable industrialisation.
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...
Aryal, R, Chong, MN, Beecham, S & Mainali, B 2017, 'Identifying the first flush in stormwater runoff using UV spectroscopy', Desalination and Water Treatment, vol. 96, pp. 231-236.View/Download from: Publisher's site
© 2017 Desalination Publications. All rights reserved. Stormwater often contains a wide range of chemical pollutants. In stormwater harvesting, separation of the polluted first flush is a significant but important challenge. Current practices are generally empirical and provide very approximate estimates of the finish of the first flush period. Since the first flush is significantly more expensive to treat, it is essential to accurately separate the first flush from the rest of the runoff in order to treat only the required volume. This is only possible when a real-time monitoring method is applied. This paper evaluates the feasibility of using UV spectroscopic methods to rapidly characterize stormwater pollutants over time in order to provide enough information to separate the first flush from the remaining volume to be harvested. Three stormwater events are used to demonstrate that relative comparison of UV spectra over time can be used to readily identify the end point of the first flush. The findings from this study will enable urban stormwater planners and engineers to more reliably and rapidly separate and treat stormwater for reuse in real-time.
Rippy, MA, Deletic, A, Black, J, Aryal, R, Lampard, J-L, Tang, JY-M, McCarthy, D, Kolotelo, P, Sidhu, J & Gernjak, W 2017, 'Pesticide occurrence and spatio-temporal variability in urban run-off across Australia', WATER RESEARCH, vol. 115, pp. 245-255.View/Download from: Publisher's site
Yadav, MK, Short, MD, Aryal, R, Gerber, C, van den Akker, B & Saint, CP 2017, 'Occurrence of illicit drugs in water and wastewater and their removal during wastewater treatment', Water Research, vol. 124, pp. 713-727.View/Download from: Publisher's site
© 2017 Elsevier Ltd This review critically evaluates the types and concentrations of key illicit drugs (cocaine, amphetamines, cannabinoids, opioids and their metabolites) found in wastewater, surface water and drinking water sources worldwide and what is known on the effectiveness of wastewater treatment in removing such compounds. It is also important to amass information on the trends in specific drug use as well as the sources of such compounds that enter the environment and we review current international knowledge on this. There are regional differences in the types and quantities of illicit drug consumption and this is reflected in the quantities detected in water. Generally, the levels of illicit drugs in wastewater effluents are lower than in raw influent, indicating that the majority of compounds can be at least partially removed by conventional treatment processes such as activated sludge or trickling filters. However, the literature also indicates that it is too simplistic to assume non-detection equates to drug removal and/or mitigation of associated risks, as there is evidence that some compounds may avoid detection via inadequate sampling and/or analysis protocols, or through conversion to transformation products. Partitioning of drugs from the water to the solids fraction (sludge/biosolids) may also simply shift the potential risk burden to a different environmental compartment and the review found no information on drug stability and persistence in biosolids. Generally speaking, activated sludge-type processes appear to offer better removal efficacy across a range of substances, but the lack of detail in many studies makes it difficult to comment on the most effective process configurations and operations. There is also a paucity of information on the removal effectiveness of alternative treatment processes. Research is also required on natural removal processes in both water and sediments that may over time facilitate further removal of these co...
Aryal, R, Grinham, A & Beecham, S 2016, 'Insight into dissolved organic matter fractions in Lake Wivenhoe during and after a major flood', ENVIRONMENTAL MONITORING AND ASSESSMENT, vol. 188, no. 3.View/Download from: Publisher's site
Aryal, R, Nirola, R, Beecham, S & Kamruzzaman, M 2016, 'Impact of elemental uptake in the root chemistry of wetland plants', INTERNATIONAL JOURNAL OF PHYTOREMEDIATION, vol. 18, no. 9, pp. 936-942.View/Download from: Publisher's site
Aryal, R, Nirola, R, Beecham, S & Sarkar, B 2016, 'Influence of heavy metals in root chemistry of Cyperus vaginatus R.Br: A study through optical spectroscopy', INTERNATIONAL BIODETERIORATION & BIODEGRADATION, vol. 113, pp. 201-207.View/Download from: Publisher's site
Aryal, R, Yadav, M, Hussain, S, Beecham, S & Diprose, D 2016, 'Tracking changes in fluorescent organic composition in leachates using excitation emission matrix-parallel factor analysis', PROCESS SAFETY AND ENVIRONMENTAL PROTECTION, vol. 103, pp. 507-516.View/Download from: Publisher's site
Hor, KY, Chee, JMC, Chong, MN, Jin, B, Saint, C, Poh, PE & Aryal, R 2016, 'Evaluation of physicochemical methods in enhancing the adsorption performance of natural zeolite as low-cost adsorbent of methylene blue dye from wastewater', JOURNAL OF CLEANER PRODUCTION, vol. 118, pp. 197-209.View/Download from: Publisher's site
Nirola, R, Megharaj, M, Aryal, R & Naidu, R 2016, 'Screening of metal uptake by plant colonizers growing on abandoned copper mine in Kapunda, South Australia', INTERNATIONAL JOURNAL OF PHYTOREMEDIATION, vol. 18, no. 4, pp. 399-405.View/Download from: Publisher's site
Nirola, R, Megharaj, M, Aryal, R, Thavamani, P, Ramdass, K, Sarkar, B & Saint, C 2016, 'Stress responses and specific metal exclusion on mine soils based on germination and growth studies by Australian golden wattle', ECOLOGICAL INDICATORS, vol. 71, pp. 113-122.View/Download from: Publisher's site
Nirola, R, Megharaj, M, Beecham, S, Aryal, R, Thavamani, P, Vankateswarlu, K & Saint, C 2016, 'Remediation of metalliferous mines, revegetation challenges and emerging prospects in semi-arid and arid conditions', ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH, vol. 23, no. 20, pp. 20131-20150.View/Download from: Publisher's site
Nirola, R, Megharaj, M, Saint, C, Aryal, R, Thavamani, P, Venkateswarlu, K, Naidu, R & Beecham, S 2016, 'Metal bioavailability to Eisenia fetida through copper mine dwelling animal and plant litter, a new challenge on contaminated environment remediation', INTERNATIONAL BIODETERIORATION & BIODEGRADATION, vol. 113, pp. 208-216.View/Download from: Publisher's site
Nirola, R, Megharaj, M, Venkateswarlu, K, Aryal, R, Correll, R & Naidu, R 2016, 'Assessment of metal toxicity and bioavailability in metallophyte leaf litters and metalliferous soils using Eisenia fetida in a microcosm study', ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY, vol. 129, pp. 264-272.View/Download from: Publisher's site
Aryal, R, Beecham, S & Lee, B-K 2015, 'Evaluation of particle transport in permeable pavements under oil loadings', KSCE JOURNAL OF CIVIL ENGINEERING, vol. 19, no. 7, pp. 2000-2004.View/Download from: Publisher's site
Aryal, R, Beecham, S, Kamruzzaman, M, Conner, S & Lee, B-K 2015, 'Temporal change of PM10 and its mass fraction during a dust storm in September 2009 in Australia', AIR QUALITY ATMOSPHERE AND HEALTH, vol. 8, no. 5, pp. 483-494.View/Download from: 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, Furumai, H, Nakajima, F, Beecham, S & Lee, B-K 2015, 'Analysis of the built-up processes for volatile organics and heavy metals in suspended solids from road run-off', DESALINATION AND WATER TREATMENT, vol. 54, no. 4-5, pp. 1254-1259.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
Chong, MN, Tneu, ZY, Poh, PE, Jin, B & Aryal, R 2015, 'Synthesis, characterisation and application of TiO2-zeolite nanocomposites for the advanced treatment of industrial dye wastewater', JOURNAL OF THE TAIWAN INSTITUTE OF CHEMICAL ENGINEERS, vol. 50, pp. 288-296.View/Download from: Publisher's site
Kamruzzaman, M, Aryal, R, Beecham, S, Mulcahy, D, Metcalfe, AV, Slattery, S & Lee, SS 2015, 'PM10 Dispersion in Adelaide and Its Relationship with Rainfall', WATER AIR AND SOIL POLLUTION, vol. 226, no. 12.View/Download from: Publisher's site
Nirola, R, Megharaj, M, Palanisami, T, Aryal, R, Venkateswarlu, K & Ravi Naidu 2015, 'Evaluation of metal uptake factors of native trees colonizing an abandoned copper mine – a quest for phytostabilization', Journal of Sustainable Mining, vol. 14, no. 3, pp. 115-123.View/Download from: Publisher's site
© 2015 The Authors Accumulation and enrichment of heavy metals in the above ground parts of Australian native Acacia pycnantha (Ap) and Eucalyptus camaldulensis (Ec) growing in an abandoned copper mine located in Kapunda, South Australia have been studied. Cu and other metals (Na, Al, K, Ca, Fe, Zn, Cd and Pb) in plants and corresponding soils were analysed to evaluate plant interaction with soils containing heavy metals. As per the total metal analysis of leaf and corresponding soil samples, Ap accumulated 93.6 mg kg−1 of Cu in leaf while the corresponding soil concentration was 1632 mg kg−1. The Ec accumulated 5341 mg kg−1 of Cu in leaf while the concentration of this heavy metal in soil was 65 mg kg−1 in soil. The ESEM spectral analysis also showed a high leaf concentration of Cu in Ec (7%) as against only 0.12% in Ap. The average bioconcentration factor for Cu, Zn, Cd and Pb in Ec was much higher than that of Ap. Similarly, enrichment factor was more in Ec for Cu, Zn and Pb than in Ap. In contrast, translocation factor for only Zn and Cd was high in Ap. This study points out that Ec and Ap have different stabilising potential in remediating heavy metals like Cu in mined soils.
Aryal, RK, Duong, TTT, Lee, BK, Hossain, MA, Kandel, D, Kamruzzaman, M, Beecham, S & Chong, MN 2014, 'Organic matter composition variability in road sediment and its role in binding heavy metals', Sustainable Environment Research, vol. 24, no. 2, pp. 81-91.
Organic matter is one of the most important factors in heavy metals mobility in soil and sediment. This study investigated the organic matter composition and metallic elements in the road sediment particles of four sizes < 75 μm, 75 to 180, 180 to 800 μm and 800 to 2000 μm collected from fine land-use types in Ulsan, which is the largest industrial city, in South Korea. The land use types include a national-scale industrial complex, industrial vicinity, a heavy trafficked area, as well as residential and rural areas. Organic matter composition using a fluorescence technique coupled with fluorescence regional integration revealed variation in specific organic matter in road sediment fractions. The concentrations of metals were high in the finer fractions. The relationship between organic matter and heavy metals was investigated by correlating specific organic matter and individual heavy metal species. Among the metals measured, Zn showed positive correlation with aromatic protein type, humic type and microbial by-products and Cd showed negative correlation with fulvic acid. The result showed that the nature of specific organic matter varies with particle sizes and its binding strength may result in accumulation of specific metals.
Hussain, S, van Leeuwen, J, Chow, CWK, Aryal, R, Beecham, S, Duan, J & Drikas, M 2014, 'Comparison of the coagulation performance of tetravalent titanium and zirconium salts with alum', CHEMICAL ENGINEERING JOURNAL, vol. 254, pp. 635-646.View/Download from: Publisher's site
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
Chong, MN, Sidhu, J, Aryal, R, Tang, J, Gernjak, W, Escher, B & Toze, S 2013, 'Urban stormwater harvesting and reuse: a probe into the chemical, toxicology and microbiological contaminants in water quality', ENVIRONMENTAL MONITORING AND ASSESSMENT, vol. 185, no. 8, pp. 6645-6652.View/Download from: Publisher's site
Hussain, S, van Leeuwen, J, Chow, C, Beecham, S, Kamruzzaman, M, Wang, D, Drikas, M & Aryal, R 2013, 'Removal of organic contaminants from river and reservoir waters by three different aluminum-based metal salts: Coagulation adsorption and kinetics studies', CHEMICAL ENGINEERING JOURNAL, vol. 225, pp. 394-405.View/Download from: Publisher's site
Sidhu, JPS, Ahmed, W, Gernjak, W, Aryal, R, McCarthy, D, Palmer, A, Kolotelo, P & Toze, S 2013, 'Sewage pollution in urban stormwater runoff as evident from the widespread presence of multiple microbial and chemical source tracking markers', SCIENCE OF THE TOTAL ENVIRONMENT, vol. 463, pp. 488-496.View/Download from: Publisher's site
Tang, JYM, Aryal, R, Deletic, A, Gernjak, W, Glenn, E, McCarthy, D & Esther, BI 2013, 'Toxicity characterization of urban stormwater with bioanalytical tools', WATER RESEARCH, vol. 47, no. 15, pp. 5594-5606.View/Download from: Publisher's site
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.
Aryal, R, Kandel, D, Acharya, D, Chong, MN & Beecham, S 2012, 'Unusual Sydney dust storm and its mineralogical and organic characteristics', ENVIRONMENTAL CHEMISTRY, vol. 9, no. 6, pp. 537-546.View/Download from: Publisher's site
Heran, M, Aryal, R, Shon, H, Vigneswaran, S, Elmaleh, S & Grasmick, A 2012, 'How To Optimize Hollow-Fiber Submerged Membrane Bioreactors', Water Environment Research, vol. 84, no. 2, pp. 115-119.View/Download from: UTS OPUS or Publisher's site
Membrane fouling is linked to reversible or irreversible accumulation of macromolecules and solids on membrane surfaces and to the irreversible adsorption inside pores. If reversible accumulation can be controlled by filtering in subcritical conditions, then adsorption could also be minimized by reducing the soluble organic matter [extracellular polymeric substances, soluble microbial products (SMP)]. This research shows how the choice of operating parameters related to biological reaction (solid retention time and the organic loading rate) can influence the process rate and the by-product (SMP) production. It also illustrates how suspension characteristics and membrane aeration can influence membrane fouling control according to the hollow fiber configuration and to the different scales of observation. The investigations were based on the definition of different fouling level and fine-tuning of a model to better understand the effects of operating parameters on membrane bioreactor filtration.
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.
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, 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.
Aryal, R, Baral, B, Vigneswaran, S, Naidu, R & Loganathan, L 2011, 'Seasonal influence on urban dust PAH profile and toxicity in Sydney, Australia', Water Science And Technology, vol. 63, no. 10, pp. 2238-2243.View/Download from: UTS OPUS or Publisher's site
Road dust is one of the major threats to the urban environment due to wash-off of dust to the surrounding catchments during wet weather period. The dust contains wide range of toxic contaminants such as heavy metals, polycyclic aromatic hydrocarbons (PAHs) and endocrine disrupting chemicals. Among the toxic contaminants, PAHs are of environmental concern due to their potential carcinogenic and mutagenic effect besides endocrine disruptive behaviour. Eighteen road dust samples from Sydney were collected in different time periods for a year and analysed for 16 US EPA PAHs. Total PAHs content range in the dust was 9â105 Î¼g/g. Total and individual PAH contents were highest in the finest size fraction (<75 Î¼m) and in winter compared to the other seasons. The PAH profiles in the different particle sizes were similar but different between the four seasons. The concentrations of higher molecular weight PAHs (4- and 5-rings) were much greater than the concentrations of lower molecular weight PAHs (2- and 3-rings). Toxicity equivalency factor application showed that the longer the dry weather period the higher the total PAHs content and toxicity in the dust.
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.
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.
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
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
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.
Sharma, G, Shon, H, Aryal, R & Phuntsho, S 2011, 'Performance evaluation of microfiltration with electrocoagulation and chemical coagulation pretreatment', Desalination and Water Treatment, vol. 34, pp. 141-149.View/Download from: UTS OPUS or Publisher's site
One of the significant parameters to be considered for evaluating the process and economic viability of crosssfl ow microfiltration (MF) is flux stability. The MF economics are dependent on the flux decay through the membrane caused by membrane fouling. This work aims to evaluate the performance of MF by electro and chemical coagulation as pretreatments. The performance of MF was found to be sensitive to pH of feed solution, coagulant dosing and generation time. Acrylonitrile butadiene styrene (ABS) MF membrane of pore size 0.4 Î¼m was used in this study. Without pretreatment normalised flux declined by 94% after 160 min of MF operation using model wastewater. However with pretreatments, the MF flux was significantly improved. The optimum performance for MF with both electro and chemical coagulation pretreatments occurred at isoelectric point where the highest removal of organic and turbidity was observed. With chemical coagulation under optimum conditions (30 mg/l alum dose and pH 6.5), MF did not experience any flux decline. MF performed better with chemical coagulation compared to electrocoagulation (EC). Also organic matter removal was found to be more for chemical coagulation than for EC.
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.
Lebegue, J, Aryal, R, Shon, H, Vigneswaran, S, Heran, M & Grasmick, A 2010, 'Identification and quantification of foulant in submerged membrane reactor', Desalination and Water Treatment, vol. 24, no. 1-3, pp. 278-283.View/Download from: UTS OPUS or Publisher's site
In submerged membrane system, membrane fouling is linked to the reversible accumulation of macromolecules and solids on the membrane surface and the irreversible sorption of soluble molecules inside the pores. In the first part of the paper, the fouling was analysed at two different aeration rates through the determination of membrane resistance due to (a) sludging (Rsludging), (b) irreversible biofilm (Rbiofilm) and (c) adsorption of organic (Radsorption). These results confirm the importance of aeration for sludge control in the bundle. In the second part of the paper, irreversible foulant obtained at different aeration rates were characterised. Membrane air flow rate limits adsorption of biopolymers onto or into the membrane surface.
Aryal, R & Lee, B 2009, 'Characteristics of Suspended Solids and Micropollutants in First-Flush Highway Runoff', Water, Air, & Soil Pollution: Focus, vol. 9, no. 5-6, pp. 339-346.View/Download from: UTS OPUS or Publisher's site
Suspended solids (SS) in the first-flush runoff on highway was monitored in six continuous events from October to December 2000 in Winterthur, Switzerland, and some characteristics of particle-bound micropollutants such as polycyclic aromatic hydrocarbons, phthalate esters, and heavy metals were investigated. Among the three micropollutants, concentration of polycyclic aromatic hydrocarbon showed similar behavior to SS. Phthalate esters showed almost no correlation, whereas heavy metals showed increase in its concentration with lowers SS concentration. Three different characteristics of the micropollutants in the first flush indicated that the first-flush phenomenon is complex, and they may not be simply stated when considering suspended solids as an index for the runoff
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, 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.
Aryal, R, Lee, BK, Karki, R, Gurung, A, Baral, B & Byeon, SH 2009, 'Dynamics of PM2.5 concentrations in Kathmandu valley', Journal of Hazardous Materials, vol. 168, no. 2-3, pp. 732-738.View/Download from: UTS OPUS or Publisher's site
This study analysed daily patterns and dynamics of PM2.5 concentrations in the Kathmandu Valley during three winters. The PM2.5 data showed a daily repetitive cycle which represents influence of local air flow and dispersion and accumulation of air pollutants in the valley. Two concentration peaks were observed in the morning and in the evening periods, and they fell down during the daytime and the nighttime periods. This indicates local emission sources as major contributors in the valley. The more pronounced morning peak compared to the evening peak showed that the upslope wind in the morning helped to move the polluted inversion layer downward, subsequently adding to freshly emitted pollutants and causing a sharp pollutant concentration rise in the morning. Katabatic wind and rise of temperature in the basin during the day helped the pollutant upflow and dilution, resulting in a sharp PM2.5 concentration decline. Through the afternoon, the decrease in air temperature followed by decrease in wind speed caused to lower PM2.5 peaks in the evening. Also. higher morning peaks of PM2.5 concentrations compared to the evening indicated pollution from the previous day is added to the fresh emission. The valley had increased PM2.5 from the beginning of October which continued till the first week of February. The increase in PM2.5 peak fit the logistic equation y = [k/(1 + exp (p - qx)] + a sin(bx) where k, p, q, a, and b are constants.
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.
Guo, W, Ngo, H, Vigneswaran, S, Dharmawan, F, Nguyen, V & Aryal, R 2009, 'Effect of different flocculants on short-term performance of submerged membrane bioreactor', Separation and Purification Technology, vol. 70, no. 3, pp. 274-279.View/Download from: UTS OPUS or Publisher's site
This study aims at evaluating the impacts of flocculant addition to a submerged membrane bioreactor (SMBR). Three types of common flocculants (FeCl3, PACl and chitosan) were tested based on the performance of organic and nutrients removal, respiration test and fouling control. The data showed that all of the flocculants not only could keep high removal efficiencies of DOC and COD (>90%) compared to SMBR alone, but also exhibited different advantages and disadvantages according to the properties of the flocculants. For instance, inorganic flocculants strongly affected the nitrification process and organic flocculant addition slightly reduced the phosphorus removal efficiency in SMBR. After adding FeCl3 and PACl, NH4-N removal decreased to 31.9% and 11.1%, while T-N removal dropped to 22% and 0.5% respectively. Although flocculants addition improved sludge settleability and oxygen transfer to some extent, organic flocculant obtained more stable sludge volume indexes (SVI) and specific oxygen uptake rates (SOUR) than those of inorganic flocculants. Inorganic flocculants, on the other hand, led to more reduction of soluble microbial products (SMP) present in mixed liquor and lower membrane fouling rates (1.3 and 2.6 kPa/day for FeCl3 and PACl respectively).
Shon, H, Puntsho, S, Chon, K, Aryal, R, Vigneswaran, S, Kim, IS & Cho, J 2009, 'A study on the influence of ionic strength on the elution behaviour of membrane organic foulant using advanced separation tools', Desalination and Water Treatment, vol. 11, no. 1-3, pp. 38-45.View/Download from: UTS OPUS or Publisher's site
Although membrane technology has become a reliable and viable alternative for water and wastewater treatment, membrane fouling is a serious challenge. In this case study, we report application of different techniques to extract foulant from the hollow fi bre membrane and characterize the foulant into various components of organic, inorganic and different fractions. The organic foulant was subjected to high-pressure size exclusion chromatography (HPSEC) and fl ow fi eld-fl ow fractionation (FlFFF) analysis to study the infl uence of ionic strength on its elution behaviour using NaCl and CaCl2 as carrier solutions. It was observed that an increase in ionic strength delayed the elution time of both the organic foulant and the Na-salt of Polysterene sulphone (PSS) with HPSEC. However, no such effect was observed with FlFFF analysis. Such study is signifi cant because the characteristics of the membrane organic foulant are believed to be infl uenced by the carrier ionic conditions and pH and, therefore their subsequent interaction with the membrane and membrane fouling process. However with FlFFF, whether the infl uence of carrier ionic strength is limited to certain type of ionic carriers or certain groups of natural organic matter is a scope for further research.
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.
Aryal, R, Furumai, H, Nakajima, F & Hossain, M 2007, 'Vertical distribution and speciation of heavy metals in stormwater infiltration facilities: possible heavy metals release to groundwater', Water Practice & Technology, vol. 2, no. 2, pp. 1-8.View/Download from: UTS OPUS or Publisher's site
The infiltration inlet facilities on the side of the road along with the sewage system have been constructed two decades ago in highly urbanized residential area in Tokyo. Possible release of heavy metals from the infiltration inlet was studied by analyzing sediment samples in different vertical depth. Seven heavy metals (Cr, Mn, Co, Ni, Cu, Zn and Pb) were measured. The heavy metal contents in sediment decreased with depth. The low content of heavy metals at the bottom sediment compared to the top indicated possible release of heavy metals from the inlet sediment. The heavy metals speciation study showed that the order of the extractability/mobility in the sediment in acid exchangeable fraction was Zn and Mn>Co>Ni>Cu >Cr and Pb. The mobility order in road dust also followed the similar pattern. In reducible fraction (metal oxide bound) Pb was the most mobile in the sediment while the other metals mobility order was not similar. In oxidizable fraction (organic and sulfide bound) the order was different for the sediment and road dusts. The residual fraction contained 18 to 83% heavy metals. The presence of heavy metals in acid exchangeable, reducible and oxidizable fractions indicated a future possibility of their release to the underlying soil and the groundwater.
Aryal, R, Furumai, H, Nakajima, F & Jinadasa, H 2007, 'The Role of inter-event time definition and recovery of initial/depression loss for the accuracy in quantitative runoff simulation in highway', Journal of Urban Water, vol. 4, no. 1, pp. 53-58.View/Download from: UTS OPUS or Publisher's site
A long-term runoff monitoring was carried out in a highway drainage system in Winterthur, Switzerland. Several runoff quantity simulations were carried out using the distributed model 'InfoWorks-CS'. Serial rainfall monitoring data were used for investigation of water runoff behaviour from the highway. The inter-event time definition was calculated from the runoff simulation and applied for better accurate runoff volume determination. Under continuous rainfall condition, the quantity simulation showed a good agreement with the measured hydrograph. However, in some cases where rainfall was not continuous, overestimation of runoff volume and difference in peak height/timing was found after rainfall halting. It was believed that the initial/depression loss on road surface was recovered during the halting period of rainfall and caused the difference in the runoff volume and peak height/timing difference in simulation. The consideration of regenerated depression loss significantly improved runoff simulation results in the on-and-off type rainfall events. This result showed that it was essential to estimate the inter-event time definition to consider appropriateness of the initial or intermediate loss.
Hossain, M, Furumai, H, Nakajima, F & Aryal, R 2007, 'Heavy metals speciation in sediment accumulation within infiltration facility and evaluation of metal retention properties of underlying soil', Water Science And Technology, vol. 56, no. 11, pp. 81-89.View/Download from: UTS OPUS
Heavy metals speciation analysis was carried out on sediment samples accumulated within soakaways in an old stormwater infiltration facility in Tokyo, Japan and on a soil core sample collected near the facility. Heavy metals content in soakaways sediments were much elevated compared to nearby surface soil with the content for Zn, Pb and Cd reaching about 5 to 10 times the content in surface soil. Speciation results revealed that significant amount of the accumulated heavy metals were present in potential mobile fractions, posing threat of release to underlying soil with changing environmental conditions. Detail analyses of soil characteristics indicated significant heterogeneity with depth, especially between the surface soil and underlying soil at site. Decrease in potential adsorption sites with depth was observed in case of underlying soil. Reduced adsorption capacity for heavy metals was evidenced for underlying soil when compared with surface soil. Furthermore, less capability of the soil organic matter to bind heavy metals was evidenced through speciation analyses, which raises concern over the long-term pollution retention potential of the underlying soil receiving infiltrated runoff.
Hossain, MA, Furumai, H, Nakajima, F & Aryal, RK 2007, 'Heavy metals speciation in soakaways sediment and evaluation of metal retention properties of surrounding soil', WATER SCIENCE AND TECHNOLOGY, vol. 56, no. 11, pp. 81-89.View/Download from: Publisher's site
Aryal, R, Furumai, H, Nakajima, F & Boller, M 2006, 'Characteristics of particle-associated PAHs in a first flush of a highway runoff', Water Science And Technology, vol. 53, no. 2, pp. 245-251.View/Download from: UTS OPUS or Publisher's site
Runoff monitoring of six rainfall events was carried out in a highway, Winterthur, Switzerland focusing on first flush (runoff volume up to 2.88 mm). Six runoff events were used to investigate the characteristics of particle-associated PAHs in first flush. The fine fraction (<45 ?m) had a relatively higher contribution than the coarse fraction. A significant contribution of the coarse fraction was observed at some periods when the runoff flow rapidly increased. Fluctuation of PAH content during a runoff event was significant in the coarse fraction and, in contrast, the PAH content in the fine fraction was less fluctuating. The weighted average PAH content in each event ranged from 17 to 62 ?g/g in total SS, from 23 to 54 ?g/g in the fine fraction and from 16 to 84 ?g/g in the coarse fraction. The loading of particle-associated PAHs from the first flush of highway runoff ranged from 0.06 to 0.22 g/ha in a total of 12 PAH species. Keywords First flush; highway runoff; PAH content; PAH profiles; suspended solids.
Aryal, R, Furumai, H, Nakajima, F, Murakami, M & Jinadasa, H 2006, 'Prolonged deposition of heavy metals in infiltration facilities and its possible threat to groundwater contamination', Water Science and Technology, vol. 54, no. 6-7, pp. 205-212.View/Download from: UTS OPUS or Publisher's site
A field investigation of infiltration facilities, built two decades ago in Tokyo, was carried out and sediment samples were collected from 12 infiltration inlets of three different locations. Heavy metals contents in the inlet sediment, road dusts and soils samples were analysed and compared. The particle size distribution analysis showed its variation in depth as well as from inlet to inlet. The nature of organic substances present in sediment found changes in particle sizes as well as in depth. The heavy metals content in the sediment samples ranged from 6-143 (Cr), 1-84 (Ni), 49-331 (Cu), 210-2186 (Zn) and 2-332 (Pb) microg/g. The heavy metal content ranges were similar to road dust, which indicated road dust as a possible source for sediment for the infiltration inlets. The lower heavy metals content in many sediment samples than the soil indicated possible release/desorption of heavy metals under newly created environments such as an anaerobic environment. Among the heavy metals there was a relatively good relationship between Cu and Zn, indicating the existence of their common sources.
Murakami, M, Nakajima, F, Furumai, H & Aryal, R 2006, 'Estimation of infiltration volumes from infiltration facilities at rainfall events with different characteristics', Journal of Water and Waste, vol. 19, no. 5, pp. 443-460.
Aryal, R, Furumai, H, Nakajima, F & Boller, M 2005, 'Dynamic behaviour of fractional suspended solids and particle-bound polycyclic aromatic hydrocarbons in highway runoff', Water Research, vol. 39, no. 20, pp. 5126-5134.View/Download from: UTS OPUS or Publisher's site
A long-term continuous runoff monitoring was carried out in a highway in Winterthur, Switzerland. The total suspended solids (TSS) samples were fractionated into fine (<45 ?m) and coarse (>45 ?m) fraction and their washoff behavior was studied. The fine and coarse fraction showed different washoff behaviors. During the runoff the concentration of the fine fraction was less fluctuated compared to coarse. The fluctuation of the coarse fraction was more influenced by TSS concentration. The PAH content measurement in fine fraction showed less fluctuation compared to the coarse fraction. The PAH content in the coarse fraction was found decreasing with increasing the coarse fraction contribution to TSS.
Aryal, R, Jinadasa, H, Furumai, H & Nakajima, F 2005, 'A long-term suspended solids runoff simulation in a highway drainage system', Water Science And Technology, vol. 52, no. 5, pp. 159-167.View/Download from: UTS OPUS
A long-term monitoring investigation was carried out in a highway drainage system in Winterthur, Switzerland. Several runoff quality and quantity simulations were carried out using the distributed model "InfoWorks-CS". Serial rainfall monitoring data was used for investigation of SS runoff behavior from the highway. Under continuous rainfall conditions, the quantity simulation showed a good agreement with the measured hydrograph. However, in some cases where rainfall was not continuous, overestimation of the peak height was found at the later stage after the end of the rainfall. It was believed that the initial/depression loss on the road surface was recovered during the halting period of rainfall. The consideration of regenerated depression loss significantly improved runoff simulation results in the on-and-off type rainfall events. A single event quality simulation underestimated the SS load in light rainfall events. One of the reasons was possibly inadequate consideration of pipe sediment conditions. A long term simulation was carried out to establish the initial condition of surface and pipe sediment for the target event. The newly simulated pollutograph gave a good agreement with the measured one. It revealed that it was essential to consider appropriateness of the initial condition of pipe sediment as well as surface sediment.
Furumai, H, Jinadasa, H, Murakami, M, Nakajima, F & Aryal, R 2005, 'Model description of storage and infiltration functions of infiltration facilities for urban runoff analysis by a distributed model', Water Science And Technology, vol. 52, no. 5, pp. 53-60.View/Download from: UTS OPUS
Although there have been simulation researches focusing on reduction of stormwater peak flow by introduced infiltration facilities, model simulation of dynamic runoff behavior is still limited for frequently occurring rainfall events with weak intensity. Therefore, dynamic simulation was carried out in two urban drainages with infiltration facilities incorporated with a distributed model using two methods for describing functions of infiltration facilities. A method adjusting effective rainfall model gave poor simulation of runoff behavior in light rainfalls. Another method considering dynamic change of storage capacity as well as infiltration rate gave satisfactory estimation of the runoff in both drainages. In addition, assumption of facility clogging improved the agreement between measured and simulated hydrographs in small and medium-sized rainfall. Therefore, the proposed method might be useful for quantifying the secondary effects of the infiltration facilities on groundwater recharge and urban non-point pollutant trapping as well as runoff reduction.
Kidwai, M, Aryal, R & Mishra, P 2001, 'Microwave assisted synthesis of novel pyrazoles', Indian Journal of Chemistry, vol. 40B, no. 8, pp. 717-718.
Kidwai, M, Aryal, RK & Misra, P 2001, 'Microwave assisted synthesis of novel pyrazoles', INDIAN JOURNAL OF CHEMISTRY SECTION B-ORGANIC CHEMISTRY INCLUDING MEDICINAL CHEMISTRY, vol. 40, no. 8, pp. 717-718.
Acharya, PD, Aryal, R & Lamichhane, J 1998, 'Adsorption Characteristics of Lissamine Red Dye on Ash in Aqueous solution', Journal of Nepal Chemical Society, vol. 1718, pp. 51-57.
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.
Aryal, R, Sidhu, JPS, Chong, MN, Toze, S, Keller, J & Gernjak, W 2012, 'Inter-storm dissolved organic matter variability and its role in microbial transport during urban runoff events', WSUD 2012 - 7th International Conference on Water Sensitive Urban Design: Building the Water Sensitive Community, Final Program and Abstract Book.
At present major challenges in stormwater harvesting and reuse remain on the characterization of non-point source pollutants, especially microbial pathogens, and the associated public health risks due to the intrinsic short-term acute health risks. Due to the negative surface charge of most microbes, their transport in urban stormwater often relies on the attachment to particulate matter, suspended solids and organic matter. In this study, the transport behavior of two microbes, Escherichia coli and Enterococcus spp. and their relationship with dissolved organic matter present in stormwater were investigated over five stormwater runoff events collected from a medium density residential urban catchment in South East Queensland. Analyses on organic matter included hydrophobic and hydrophilic fractions. The hydrophillic substances were further fractionated into humic substances, building blocks and low molecular weight organics. Escherichia coli numbers of 3.6x10 3 cfu 100mL -1were detected in the stormwater runoff, while Enterococcus spp. numbers as high as 3x 10 4 cfu 100mL -1 were detected. The mean dissolved organic carbon in the stormwater samples was 5.1±1.9 mg/L in which hydrophilic constituted the highest mass fraction (60-80%). Results showed that microbial transport was hindered by an increase of the hydrophilic organics fraction, especially the humic fraction.
Chong, MN, Aryal, R, Sidhu, J, Tang, J, Toze, S & Gardner, T 2011, 'Urban stormwater quality monitoring: From sampling to water quality analysis', Proceedings of the 2011 7th International Conference on Intelligent Sensors, Sensor Networks and Information Processing, ISSNIP 2011, pp. 174-179.View/Download from: Publisher's site
This paper presents the outcomes of urban stormwater quality monitoring and research including associated activities in South East Queensland (SEQ). The issues associated with urban stormwater quality monitoring, ranging from automated field sampling to laboratory analysis of chemical, toxicological and microbiological constituents present in stormwater are elaborated. A medium density residential stormwater supply catchment of 290 hectares in northern Brisbane is presented as a case study and discussed in detail. Preliminary results indicate that the occurrence and concentration of chemical pollutants in urban stormwater runoff and the associated baseline toxicity is relatively low. However, the microbiological quality of stormwater may not be as good as initially perceived with high numbers of faecal indicator bacteria (FIB) detected during wet weather events. In addition, the polymerase chain reaction (PCR) detection of pathogens indicated the presence of human sewage contamination during wet weather events which might be due to potential sewer overflow events. Further monitoring will be conducted to further assess the stormwater quality before undertaking a comprehensive environmental and public health risk assessment. © 2011 IEEE.
Aryal, R, Furumai, H, Nakajima, F & Hossain, MA 2008, 'Spatial distribution and speciation of heavy metals in soakaway sediment', Website Proceedings of the 11th International Conference on Urban Drainage, International Conference on Urban Drainage, IWA, Edinburgh, Scotland, UK, pp. 1-8.View/Download from: UTS OPUS
The infiltration facilities on a side of the road along with a sewage system have been constructed in 80âs in highly urbanized residential area in Tokyo. Sediment samples deposited frequently during wet weather periods in infiltration soakaways were collected and heavy metals (Cr, Mn, Co, Ni, Cu, Zn and Pb) were analyzed. Wide range of spatial variation in heavy metals contents was found in the area. Spatial variation of the contents of individual soakaway specific in deposition of metals reflecting the nature of diffuse urban pollution complexity. The content of heavy metals in lower sediment layer of infiltration soakaway was low compared to the upper sediment layer. Heavy metals speciation analysis revealed possible release of heavy metals from the sediments in the lower layer with time possibly due to slow changing sediment environment.
Aryal, R, Kim, A & Lee, BK 2008, 'Particle size distribution and heavy metals content in industrial atmosphere', 5th SETAC - Society of Environmental Toxicology and Chemistry (SETAC), Society of Environmental Toxicology and Chemistry, Ulsan, Republic of Korea.
Lee, BK, Kim, A, Dong, T, Duong, T, Jeong, UR, Lee, HK & Aryal, R 2007, 'Size distribution and heavy metals contents of particles collected at industrial areas', Proc. 14th International Union of Air Pollution Prevention and Environmental Protection Associations (IUAPPA) World Congress 2007, 18th Clean Air Society of Australia and New Zealand (CASANZ) Conf..
This study analyzed size distribution and heavy metal content of particles collected from the non-ferrous metal and petrochemical industrial complex (IC) areas of Ulsan, the largest industrial city in Korea, during the summer season. An ambient cascade impactor was used for daily PM samplings. The originally collected and size-separated PMs were combined as three size groups, such as 0-1.1, 1.1-4.7, and 4.7-10 μm, of the particles for analysis of heavy metals. The average concentrations of PM10 collected in the petrochemical IC (Petro IC) and the non-ferrous metal IC (NFM IC) areas during the sampling periods were 60.0 and 51.2 μg/m3, respectively. The highest mass fraction of PM was observed in the size range of 0.4-0.7 μm in the Petro IC site in 0.7-1.0 and 4.7-5.8 μm in the NFM IC. The average fractions of PM2.5 out of PM10 concentrations were about 68 and 43% in the Petro IC and the NFM IC sites, respectively. The average fractions of fine particles, 0-1.1 μm, were 25.1 μg/m3 and 41.8 % in the Petro IC site, respectively. However, they were 15.2 μg/m3 and 29.0 % in the NFM IC site, respectively. Their values of coarse particles, 4.7-10 μm, were 13.5 μg/m3 and 22.5 %, respectively, in the Petro IC site and 16.6 μg/m3 and 31.6 % in the NFM IC site. The total concentrations of cadmium, zinc and lead in the PM samples from the NFM IC site were much higher than those in the Petro IC site. However, the total concentrations of copper and lead from the NFM IC site were much lower than those in the Petro IC site. The concentrations of heavy metals from three size groups of the PMs were similar in the NFM IC site, but their values from the coarse particles were much higher than those from fine particles in the Petro IC site. This difference in PM and heavy metal levels between two ICs is caused by difference in their main business types.
Lee, BK, Kim, A, Dong, T, Duong, T, Jeong, UR, Lee, HK & Aryal, R 2007, 'Size distribution and heavy metals contents of particles collected at industrial areas', Proc. 14th International Union of Air Pollution Prevention and Environmental Protection Associations (IUAPPA) World Congress 2007, 18th Clean Air Society of Australia and New Zealand (CASANZ) Conf..
The size distribution and heavy metal content of particles collected from the non-ferrous metal and petrochemical industrial complex (IC) areas of Ulsan, South Korea, during the summer season were studied. An ambient cascade impactor was used for daily PM samplings. The average concentrations of PM10 collected in the petrochemical IC (Petro IC) and the non-ferrous metal IC (NFM IC) areas during the sampling periods were 60 and 51.2 μg/cu m, respectively. The highest mass fraction of PM was observed in the size range of 0.4-0.7 μm in the Petro IC site in 0.7?1 and 4.7-5.8 μm in the NFM IC. The total concentrations of Cd, Zn, and Pb in the PM samples from the NFM IC site were much higher than those in the Petro IC site. However, the total concentrations of copper and lead from the NFM IC site were much lower than those in the Petro IC site. The concentrations of heavy metals from three size groups of the PM were similar in the NFM IC site, but their values from the coarse particles were much higher than those from fine particles in the Petro IC site. This difference in PM and heavy metal levels between two ICs was caused by difference in their main business types. This is an abstract of a paper presented at the 14th International Union of Air pollution Prevention and Environmental Protection Associations World Congress 2007 (Brisbane, Queensland 9/9-13/2007).
Furumai, H, Aryal, RK & Nakajima, F 2002, 'Profile analysis of polycyclic aromatic hydrocarbons and heavy metals in size fractionated highway dust and runoff samples', Global Solutions for Urban Drainage, pp. 1-13.
A runoff monitoring was conducted at a highway drainage system in Switzerland. The runoff samples with higher SS concentration had higher heavy metals and PAH concentrations. The particle-bound Zn, Cu, Pb, and PAH concentrations were 155-524μg/L, 29-69μg/L, 13-46μg/L, and1.3-3.3μg/L, which were close to literature values. Particle size distribution analysis revealed that the runoff samples with higher SS concentrations contained coarser size fractions. Coarser fractions (>106μm) occupied more than half under the maximum peak flow condition, while the major particles were finer than 45μm at low flow rate. It was outstanding that the contents of heavy metals (Zn, Cu, and Pb) were about ten times higher in the runoff samples than in the three size-fractionated dusts (<50, 50-125, 125-250μm fractions). The heavy metal profile of the runoff sample was similar to those of the finer fractions of the dusts. The PAH content was higher in the dusts than the runoff samples, although the contents were both in the same range of 10-50μg/g. The PAH profiles in the fine size fractions (<50, 50-125, and 125-250μm) of the dusts looked similar except for higher percentage of B(a)An in the <50μm fraction. On the contrary, the fraction of 250-400μm had a different feature expressed by higher percentages of Ipy and B(ghi)Pe. Difference of PAH profiles among the seven runoff composite samples was negligible in spite of their different particle size distributions. The similarity reflected the fact that runoff particles mainly consisted of fine particles and the fine size fractions of the dust had similar PAH profile. However, the dusts and the runoff particles showed different PAH profile.