Ahmed, MB, Alam, MM, Zhou, JL, Xu, B, Johir, MAH, Karmakar, AK, Rahman, MS, Hossen, J, Hasan, ATMK & Moni, MA 2020, 'Advanced treatment technologies efficacies and mechanism of per- and poly-fluoroalkyl substances removal from water', Process Safety and Environmental Protection, vol. 136, pp. 1-14.View/Download from: Publisher's site
© 2020 Institution of Chemical Engineers The increasing occurrence of chemically resistant per- and poly-ﬂuoroalkyl substances (PFASs) in the natural environment, animal tissues and even the human body poses a significant health risk. Temporal trend studies on water, sediments, bird, fish, marine mammal and the human show that the exposure of PFAS has significantly increased over the last 20–30 years. Different physical, biological and chemical treatment processes have been investigated for PFAS removal from water. However, there is a lack of detailed understating of the mechanism of removal by different methods, especially by different advanced chemical treatment processes. This article reviews PFASs removal efficacy and mechanism by the advanced chemical treatment methods from aqueous solution. Review shows that several advanced oxidation processes (e.g., electrochemical oxidation, activated persulfate oxidation, photocatalysis, UV-induced oxidation) are successful in degrading PFASs. Moreover, defluorination treatment, some thermal and non-thermal degradation processes are also found to be prominent for the degradation of PFASs with some limitations including process costs over physical treatment (e.g., sorption), production of toxic by-products and greenhouse gases. Finally, knowledge gaps concerning the advanced chemical treatment of PFASs are discussed.
Alam, MM, Hossain, MA, Hossain, MD, Johir, MAH, Hossen, J, Rahman, MS, Zhou, JL, Hasan, ATMK, Karmakar, AK & Ahmed, MB 2020, 'The potentiality of rice husk-derived activated carbon: From synthesis to application', Processes, vol. 8, no. 2.View/Download from: Publisher's site
© 2020 by the authors. Activated carbon (AC) has been extensively utilized as an adsorbent over the past few decades. AC has widespread applications, including the removal of different contaminants from water and wastewater, and it is also being used in capacitors, battery electrodes, catalytic supports, and gas storage materials because of its specific characteristics e.g., high surface area with electrical properties. The production of AC from naturally occurring precursors (e.g., coal, biomass, coconut shell, sugarcane bagasse, and so on) is highly interesting in terms of the material applications in chemistry; however, recently much focus has been placed on the use of agricultural wastes (e.g., rice husk) to produce AC. Rice husk (RH) is an abundant as well as cheap material which can be converted into AC for various applications. Various pollutants such as textile dyes, organic contaminants, inorganic anions, pesticides, and heavy metals can be effectively removed by RHderived AC. In addition, RH-derived AC has been applied in supercapacitors, electrodes for Li-ion batteries, catalytic support, and energy storage, among other uses. Cost-effective synthesis of AC can be an alternative for AC production. Therefore, this review mainly covers different synthetic routes and applications of AC produced from RH precursors. Different environmental, catalytic, and energy applications have been pinpointed. Furthermore, AC regeneration, desorption, and relevant environmental concerns have also been covered. Future scopes for further research and development activities are also discussed. Overall, it was found that RH-derived AC has great potential for different applications which can be further explored at real scales, i.e., for industrial applications in the future.
Rana, HK, Akhtar, MR, Islam, MB, Ahmed, MB, Lió, P, Huq, F, Quinn, JMW & Moni, MA 2020, 'Machine Learning and Bioinformatics Models to Identify Pathways that Mediate Influences of Welding Fumes on Cancer Progression', Scientific Reports, vol. 10, no. 1.View/Download from: Publisher's site
© 2020, The Author(s). Welding generates and releases fumes that are hazardous to human health. Welding fumes (WFs) are a complex mix of metallic oxides, fluorides and silicates that can cause or exacerbate health problems in exposed individuals. In particular, WF inhalation over an extended period carries an increased risk of cancer, but how WFs may influence cancer behaviour or growth is unclear. To address this issue we employed a quantitative analytical framework to identify the gene expression effects of WFs that may affect the subsequent behaviour of the cancers. We examined datasets of transcript analyses made using microarray studies of WF-exposed tissues and of cancers, including datasets from colorectal cancer (CC), prostate cancer (PC), lung cancer (LC) and gastric cancer (GC). We constructed gene-disease association networks, identified signaling and ontological pathways, clustered protein-protein interaction network using multilayer network topology, and analyzed survival function of the significant genes using Cox proportional hazards (Cox PH) model and product-limit (PL) estimator. We observed that WF exposure causes altered expression of many genes (36, 13, 25 and 17 respectively) whose expression are also altered in CC, PC, LC and GC. Gene-disease association networks, signaling and ontological pathways, protein-protein interaction network, and survival functions of the significant genes suggest ways that WFs may influence the progression of CC, PC, LC and GC. This quantitative analytical framework has identified potentially novel mechanisms by which tissue WF exposure may lead to gene expression changes in tissue gene expression that affect cancer behaviour and, thus, cancer progression, growth or establishment.
Sornalingam, K, McDonagh, A, Canning, J, Cook, K, Johir, MAH, Zhou, JL & Ahmed, MB 2020, 'Photocatalysis of 17α-ethynylestradiol and estriol in water using engineered immersible optical fibres and light emitting diodes', Journal of Water Process Engineering, vol. 33.View/Download from: UTS OPUS or Publisher's site
© 2019 Elsevier Ltd This research aims to promote photocatalysis of endocrine disrupting chemicals (EDCs) in water. Two reactor setups with (i) modified air-clad optical fibres and (ii) waterproof LED strips were utilised to transmit light to photocatalysts P25 TiO2 and gold-modified TiO2 (Au-TiO2). The performances to photodegrade 17α-ethynylestradiol (EE2) and estriol (E3) under Cool White and UVA high efficacy LEDs were examined. Au-TiO2 showed superior photocatalytic activity for EE2 removal over P25 TiO2. The pseudo first-order rate constants for EE2 photocatalysis under UVA were 0.55 h−1 and 0.89 h−1 for TiO2 and Au-TiO2, respectively. E3 was effectively degraded by Au-TiO2 in the immersible LED strip reactor (0.13 h−1).
Xu, B, Ahmed, MB, Zhou, JL & Altaee, A 2020, 'Visible and UV photocatalysis of aqueous perfluorooctanoic acid by TiO2 and peroxymonosulfate: Process kinetics and mechanistic insights', CHEMOSPHERE, vol. 243.View/Download from: UTS OPUS or Publisher's site
Xu, B, Zhou, JL, Altaee, A, Ahmed, MB, Johir, MAH, Ren, J & Li, X 2020, 'Improved photocatalysis of perfluorooctanoic acid in water and wastewater by Ga2O3/UV system assisted by peroxymonosulfate', CHEMOSPHERE, vol. 239.View/Download from: UTS OPUS or Publisher's site
Ahmed, MB, Hasan Johir, MA, Zhou, JL, Ngo, HH, Nghiem, LD, Richardson, C, Moni, MA & Bryant, MR 2019, 'Activated carbon preparation from biomass feedstock: Clean production and carbon dioxide adsorption', Journal of Cleaner Production, vol. 225, pp. 405-413.View/Download from: UTS OPUS or Publisher's site
© 2019 Elsevier Ltd The current methods used for the production of activated carbon (AC) are often chemical and energy intensive and produce significant amount of chemical waste. Thus, clean production of AC is important to reduce its overall production cost and to limit the adverse effect on the environment. Therefore, the main aim of this study is to develop a clean method for AC production from woody biomass with low chemical consumption. Herein, this study reports a facile strategy for reducing chemical usages in the production of high-performance AC, by introducing a crucial pre-pyrolysis step before chemical activation of biomass. The ACs prepared were characterised using scanning electron microscopy, Fourier transform infrared spectroscopy, nitrogen and carbon dioxide gas adsorption measurements. All these characterisations indicated that produced ACs have similar physicochemical properties. The strategy reduced chemical use by 70% and produced high-performance ultra-microporous ACs with excellent carbon dioxide adsorption capacity (4.22–5.44 mmol m −2 ). The facile pre-pyrolysis method is recommended for further research as a cleaner activated carbon preparation method from biomass feedstock.
Kien, TN, Hung, MN, Cuong, KT, Ahmed, MB, Huang, Y & Zhou, JL 2019, 'Chemical and microbiological risk assessment of urban river water quality in Vietnam', ENVIRONMENTAL GEOCHEMISTRY AND HEALTH, vol. 41, no. 6, pp. 2559-2575.View/Download from: UTS OPUS or Publisher's site
Xu, J, Cao, Z, Wang, Y, Zhang, Y, Gao, X, Ahmed, MB, Zhang, J, Yang, Y, Zhou, JL & Lowry, GV 2019, 'Distributing sulfidized nanoscale zerovalent iron onto phosphorus-functionalized biochar for enhanced removal of antibiotic florfenicol', CHEMICAL ENGINEERING JOURNAL, vol. 359, pp. 713-722.View/Download from: UTS OPUS or Publisher's site
Moni, MA, Rana, HK, Islam, MB, Ahmed, MB, Xu, H, Hasan, MAM, Lei, Y & Quinn, JMW 2019, 'A computational approach to identify blood cell-expressed Parkinson's disease biomarkers that are coordinately expressed in brain tissue', COMPUTERS IN BIOLOGY AND MEDICINE, vol. 113.View/Download from: UTS OPUS or Publisher's site
Nur, T, Loganathan, P, Ahmed, MB, Johir, MAH, Tien, VN & Vigneswaran, S 2019, 'Removing arsenic from water by coprecipitation with iron: Effect of arsenic and iron concentrations and adsorbent incorporation', CHEMOSPHERE, vol. 226, pp. 431-438.View/Download from: UTS OPUS or Publisher's site
Rana, HK, Akhtar, R, Ahmed, MB, Lio, P, Quinn, JMW, Huq, F & Moni, MA 2019, 'Genetic effects of welding fumes on the progression of neurodegenerative diseases', NEUROTOXICOLOGY, vol. 71, pp. 93-101.View/Download from: UTS OPUS or Publisher's site
Rana, HK, Akhtar, R, Islam, MB, Ahmed, MB, Lio, P, Quinn, JMW, Huq, F & Moni, MA 2019, 'Genetic effects of welding fumes on the development of respiratory system diseases', COMPUTERS IN BIOLOGY AND MEDICINE, vol. 108, pp. 142-149.View/Download from: UTS OPUS or Publisher's site
Ahmed, M, Johir, MAH, Khourshed, C, Zhou, J, Ngo, HH, Nghiem, D, Moni, M & Sun, L 2018, 'Sorptive removal of dissolved organic matter in biologically-treated effluent by functionalized biochar and carbon nanotubes: importance of sorbent functionality', Bioresource Technology.View/Download from: UTS OPUS or Publisher's site
The sorptive removal of dissolved organic matter (DOM) in biologically-treated effluent was studied by using multi-walled carbon nanotube (MWCNT), carboxylic functionalised MWCNT (MWCNT-COOH), hydroxyl functionalized MWCNT (MWCNT-OH) and functionalized biochar (fBC). DOM was dominated by hydrophilic fraction (79.6%) with a significantly lower hydrophobic fraction (20.4%). The sorption of hydrophobic DOM was not significantly affected by the sorbent functionality (∼10.4% variation) and sorption capacity followed the order of MWCNT > MWCNT-COOH > MWCNT-OH > fBC. In comparison, the sorption of hydrophilic fraction of DOM changed significantly (∼37.35% variation) with the change of sorbent functionality with adsorption capacity decreasing as MWCNT-OH > MWCNT-COOH > MWCNT > fBC. Furthermore, the affinity of adsorbents toward a hydrophilic compound (dinitrobenzene), a hydrophobic compound (pyrene) and humic acid was also evaluated to validate the proposed mechanisms. The results provided important insights on the type of sorbents which are most effective to remove different DOM fractions.
Ahmed, M, Zhou, J, Ngo, H, Johir, MAH & Kireesan, S 2018, 'Sorptive removal of phenolic endocrine disruptors by functionalized biochar:competitive interaction mechanism, removal efficacy and application in wastewater', Chemical Engineering Journal, vol. 335, pp. 801-811.View/Download from: UTS OPUS or Publisher's site
Sorptive removal of six phenolic endocrine disrupting chemicals (EDCs) estrone (E1), 17β-estradiol (E2), estriol (E3), 17α-ethynylestradiol (EE2), bisphenol A (BPA) and 4-tert-butylphenol (4tBP) by functionalized biochar (fBC) through competitive interactions was investigated. EDC sorption was pH dependent with the maximum sorption at pH 3.0-3.5 due to hydrogen bonds and π-π interactions as the principal sorptive mechanism. Sorption isotherm of the EDCs was fitted to the Langmuir model. Sorption capacities and distribution coefficient values followed the order E1 > E2 ≥ EE2 > BPA > 4tBP > E3. The findings suggested that EDC sorption occurred mainly through pseudo-second order and external mass transfer diffusion processes, by forming H-bonds along with π-π electron-donor-acceptor (EDA) interactions at different pH. The complete removal of ∼500 μg L-1 of each EDC from different water decreased in the order: deionised water > membrane bioreactor (MBR) sewage effluent > synthetic wastewater. The presence of sodium lauryl sulphonate and acacia gum in synthetic wastewater significantly suppressed sorption affinity of EDCs by 38-50%, hence requiring more fBC to maintain removal efficacy.
Ahmed, MB, Zhou, J, Ngo, HH, Johir, MAH, Sun, L, Asadullah, M & Belhaj, D 2018, 'Sorption of hydrophobic organic contaminants on functionalized biochar: protagonist role of π-π electron-donor-acceptor interactions and hydrogen bonds', Journal of Hazardous Materials.View/Download from: UTS OPUS or Publisher's site
The sorption of five potent endocrine disruptors as representative hydrophobic organic contaminants (HOCs) namely estrone (E1), 17β-estradiol (E2), estriol (E3), 17α-ethynylestradiol (EE2) and bisphenol A (BPA) on functionalized biochar (fBC) was systematically examined, with a particular focus on the importance of π-electron-donor (phenanthrene: PHEN) and π-electron-acceptors (1,3-dinitrobenzene: DNB, p-amino benzoic acid: PABA) on sorption. Experimental results suggested that hydrogen-bond formation and π-π-electron-donor-acceptor (EDA) interactions were the dominant sorption mechanisms. The sorption of HOCs decreased as E1 > E2 > EE2 > E3 > BPA based on the Freundlich and Polanyi-Mane-models. The comparison of adsorption coefficient (Kd) normalized against hexadecane-water partition coefficient (KHW) between HOCs and PHEN indicated strong π-π-EDA interactions. π-π interactions among DNB, PHEN and HOCs were verified by the observed upfield frequency (Hz) shifts using proton nuclear magnetic resonance (1H NMR) which identified the specific direction of π-π interactions. UV-vis spectra showed charge-transfer bands for π-donors (PHEN and HOCs) with the model π-acceptor (DNB) also demonstrating the role of π-π EDA interactions. The role of π-electron-donor and π-electron-acceptor domains in fBC was identified at different solution pH.
Belhaj, D, Athmouni, K, Ahmed, MB, Aoiadni, N, El Feki, A, Zhou, JL & Ayadi, H 2018, 'Polysaccharides from Phormidium versicolor (NCC466) protecting HepG2 human hepatocellular carcinoma cells and rat liver tissues from cadmium toxicity: Evidence from in vitro and in vivo tests', INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES, vol. 113, pp. 813-820.View/Download from: UTS OPUS or Publisher's site
Mohsen, M, Ahmed, MB & Zhou, JL 2018, 'Particulate matter concentrations and heavy metal contamination levels in the railway transport system of Sydney, Australia', Transportation Research Part D: Transport and Environment, vol. 62, pp. 112-124.View/Download from: UTS OPUS or Publisher's site
© 2018 Elsevier Ltd Sampling campaign was conducted over six weeks to determine particulate matter (PM) concentrations from Sydney Trains airport line (T2) at both underground and ground levels using DustTrak. Dust samples were collected and analysed for 12 metals (Fe, Ca, Mn, Cr, Zn, Cu, Pb, Al, Co, Ni, Ba and Na) by atomic emission spectroscopy. Average underground PM10 and PM2.5 concentrations from inside the trains were 2.8 and 2.5 times greater than at ground level. Similarly, PM10 and PM2.5 concentrations on underground platforms were 2.7 and 2.5 times greater than ground level platforms. Average underground PM concentrations exceeded the national air quality standards for both PM10 (50 µg/m3) and PM2.5 (25 µg/m3). Correlation analysis showed a strong to moderate association between PM concentrations at ground level and background PM concentrations (r2 from 0.952 to 0.500). The findings suggested that underground PM concentrations were less influenced by the ambient background than at ground level. The metal concentrations decreased in the order of Fe, Cr, Ca, Al, Na, Ba, Mn, Zn, Cu, Ni, Co and Pb. The pollution index (PI) and enrichment factor (EF) values were calculated to identify the levels and sources of contamination in the underground railway microenvironments. PM was remarkably rich in Fe with a mean concentration of 73.51 mg/g and EF of 61.31, followed by Ni and Cr. These results noticeably indicated a high level of metal contamination in the underground environments, with the principal contribution from track abrasion and wear processes.
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.
Sornalingam, K, McDonagh, A, Zhou, J, Johir, M & Ahmed, M 2018, 'Photocatalysis of estrone in water and wastewater: Comparison between Au-TiO2 nanocomposite and TiO2, and degradation by-products', Science of the Total Environment, vol. 610–611, pp. 521-530.View/Download from: UTS OPUS or Publisher's site
Gold-modified TiO2 (Au-TiO2) photocatalysts were utilised for the degradation of estrone (E1), a major endocrine disrupting chemical in water and wastewater. Au-TiO2 catalysts were synthesised by a deposition-precipitation method with gold loadings of 0–8% (wt%). The Au-TiO2 nanocomposite exhibited superior activity compared to P25 TiO2 under UVA (λ = 365 nm), cool white (λ > 420 nm) and green (λ = 523 nm) light emitting diodes (LEDs), for treating 1 mg l− 1 of E1. The 4 wt% Au loading was found to produce the best photocatalytic activity with a rate constant of 2.44 ± 0.36 h− 1, compared to 0.06 ± 0.01 h− 1 for P25 TiO2, under visible light. In total 4 by-products were identified, one from negative ionization mode (m/z = 269) and three from positive ionization mode (m/z = 287) during photocatalysis, which were also degraded with time by Au-TiO2. For different water matrices, the photodegradation rate of E1 decreased in the order: ultrapure water > synthetic wastewater ≈ wastewater effluent from membrane bio-reactor. Overall, 4 wt% Au-TiO2 demonstrated superior performance compared to P25 TiO2 in water and wastewater.
Altaee, A, Xu, B, Ahmed, MB, Zhou, JL, Xu, G & Wu, M 2018, 'Graphitic carbon nitride based nanocomposites for the photocatalysis of organic contaminants under visible irradiation: Progress, limitations and future directions', Science of the Total Environment, vol. 633, pp. 546-559.View/Download from: UTS OPUS or Publisher's site
Graphitic carbon nitride (g-C3N4) has drawn great attention recently because of its visible light response, suitable energy band gap, good redox ability, and metal-free nature. g-C3N4 can absorb visible light directly, therefore has better photocatalytic ability under solar irradiation and is more energy-efficient than TiO2. However, pure g-C3N4 still has the drawbacks of insufficient light absorption, small surface area and fast recombination of photogenerated electron and hole pairs. This review summarizes the recent progress in the development of g- C3N4 nanocomposites to photodegrade organic contaminants in water. Element doping especially by potassium has been reported to be an efficient method to promote the degradation efficacy. In addition, compound doping improves photodegradation performance of g-C3N4, especially Ag3PO4-g-C3N4 which can completely degrade 10 mg L−1 of methyl orange under visible light irradiation in 5 min, with the rate constant (k) as high as 0.236 min−1. Moreover, co-doping enhances the photodegradation rate of multiple contaminants while immobilization significantly improves catalyst stability. Most of g-C3N4 composites possess high reusability enabling their practical applications in wastewater treatment. Furthermore, environmental conditions such as solution pH, reaction temperature, dissolved oxygen, and dissolved organic matter all have important effects on the photocatalytic ability of g-C3N4 photocatalyst. Future work should focus on the synthesis of innovative g-C3N4 nanocomposites for the efficient removal of organic contaminants in water and wastewater.
Ahmed, M, Guo, W, Zhou, J, Johir, M & Ngo, H 2017, 'Competitive sorption affinity of sulfonamides and chloramphenicol antibiotics toward functionalized biochar for water and wastewater treatment', Bioresource Technology.View/Download from: UTS OPUS or Publisher's site
Competitive sorption of sulfamethazine (SMT), sulfamethoxazole (SMX), sulfathiazole (STZ) and chloramphenicol (CP) toward functionalized biochar (fBC) was highly pH dependent with maximum sorption at pH ∼4.0-4.25. Equilibrium data were well represented by the Langmuir and Freundlich models in the order STZ > SMX > CP > SMT. Kinetics data were slightly better fitted by the pseudo second-order model than pseudo first-order and intra-particle-diffusion models. Maximum sorptive interactions occurred at pH 4.0-4.25 through H-bonds formations for neutral sulfonamides species and through negative charge assisted H-bond (CAHB) formation for CP, in addition to π-π electron-donor-acceptor (EDA) interactions. EDA was the main mechanism for the sorption of positive sulfonamides species and CP at pH < 2.0. Sorption of negative sulfonamides species and CP at pH > 7.0 was regulated by H-bond formation and proton exchange with water by forming CAHB, respectively. The results suggested fBC to be highly efficient in removing antibiotics mixture.
Ahmed, M, zhou, J, Ngo, H, Guo, W, Johir, M & Kiressan, S 2017, 'Nano-Fe0 Immobilized onto Functionalized Biochar Gaining Excellent Stability during Sorption and Reduction of Chloramphenicol via Transforming to Reusable Magnetic Composite', Chemical Engineering Journal, vol. 322, pp. 571-581.View/Download from: UTS OPUS or Publisher's site
The widely used nanosized zero-valent iron (nZVI or nFe0) particles and their composite material lose reductive nature during application, and the stability of transformed composite material for repeatable application is not addressed to date. To shed light on this, nZVI was synthesized from scrap material and immobilized on functionalized biochar (fBC) to prepare nZVI-fBC composite. Comparative study between nZVI and nZVI-fBC composite on the removal of chlorinated antibiotic chloramphenicol from different water types was conducted. The results suggested that nZVI was solely responsible for reduction of chloramphenicol. Whereas nZVI-fBC could be applied once, within a few hours, for the reduction of chloramphenico (29–32.5%) and subsequently sorption (67.5–70.5%) by transforming to a fully magnetic composite (nFe3O4-fBC) gaining stability with synergistic sorption performance. In both cases, two reduction by-products were identified namely 2-chloro-N-[1,3-dihydroxy-1-(4-aminophenyl)propan-2-yl]acetamide (m/z 257) and dechlorinated N-[1,3-dihydroxy-1-(4-aminophenyl)propan-2-yl]acetamide (m/z 223). The complete removal of 3.1 µM L−1 of chloramphenicol in different water was faster by nZVI-fBC (∼12–15 h) than by stable nFe3O4-fBC composite (∼18 h). Both nZVI-fBC and nFe3O4-fBC composites removed chloramphenicol in the order: deionized water > lake water > synthetic wastewater. nFe3O4-fBC showed excellent reusability after regeneration, with the regenerated nFe3O4-fBC composite (after 6 cycles of application) showing significant performance for methylene blue removal (∼287 mg g−1). Therefore, the transformed nFe3O4-fBC composite is a promising and reusable sorbent for the efficient removal of organic contaminants.
Ahmed, MB, Johir, MAH, Zhou, JL, Ngo, HH, Guo, W & Sornalingam, K 2017, 'Photolytic and Photocatalytic Degradation of Organic UV Filters in Contaminated Water', Current Opinion in Green and Sustainable Chemistry, vol. 6, pp. 85-92.View/Download from: UTS OPUS or Publisher's site
UV filters as emerging contaminants are of great concern and their wide detection in aquatic environments indicates their chemical stability and persistence. This review summarized the photolytic and photocatalytic degradation of UV filters in contaminated water. The findings indicated that limited research has been conducted on the photolysis and photocatalysis of UV filters. Photolysis of UV filters through UV irradiation in natural water was a slow process, which was accelerated by the presence of photosensitisers e.g. triplet state of chromaphoric dissolved organic matter (3CDOM*) and nutrients but reduced by salinity, dissolved organic matter (DOM) and divalent cations. UV Photocatalysis of 4-methylbenzylidene camphor and 2-phenylbenzimidazole-5-sulfonic acid was very effective with 100% removal within 30 min and 90 min using medicated TiO2/H2O2 and TiO2, respectively. The radiation source, type of catalyst and oxygen content were key factors. Future research should focus on improved understanding of photodegradation pathways and by-products of UV filters.
Ahmed, MB, Zhou, JL, Ngo, HH, Guo, W, Johir, MAH & Sornalingam, K 2017, 'Single and competitive sorption properties and mechanism of functionalized biochar for removing sulfonamide antibiotics from water', Chemical Engineering Journal, vol. 311, pp. 348-358.View/Download from: UTS OPUS or Publisher's site
© 2016 Elsevier B.V.Single and competitive sorption of ionisable sulphonamides sulfamethazine, sulfamethoxazole and sulfathiazole on functionalized biochar was highly pH dependent. The equilibrium data were well represented by both Langmuir and Freundlich models for single solutes, and by the Langmuir model for competitive solutes. Sorption capacity and distribution coefficient values decreased as sulfathiazole > sulfamethoxazole > sulfamethazine. The sorption capacity of each antibiotic in competitive mode is about three times lower than in single solute sorption. The kinetics data were best described by the pseudo second-order (PSO) model for single solutes, and by PSO and intra-particle diffusion models for competitive solutes. Adsorption mechanism was governed by pore filling through diffusion process. The findings from pH shift, FTIR spectra and Raman band shift showed that sorption of neutral sulfonamide species occurred mainly due to strong H-bonds followed by π+-π electron-donor-acceptor (EDA), and by Lewis acid-base interaction. Moreover, EDA was the main mechanism for the sorption of positive sulfonamides species. The sorption of negative species was mainly regulated by proton exchange with water forming negative charge assisted H-bond (CAHB), followed by the neutralization of –OH groups by H+ released from functionalized biochar surface; in addition π-π electron-acceptor-acceptor (EAA) interaction played an important role.
Ahmed, MB, Zhou, JL, Ngo, HH, Guo, W, Thomaidis, NS & Xu, J 2017, 'Progress in the biological and chemical treatment technologies for emerging contaminant removal from wastewater: A critical review.', Journal of Hazardous Materials, vol. 323, pp. 274-298.View/Download from: UTS OPUS or Publisher's site
This review focuses on the removal of emerging contaminants (ECs) by biological, chemical and hybrid technologies in effluents from wastewater treatment plants (WWTPs). Results showed that endocrine disruption chemicals (EDCs) were better removed by membrane bioreactor (MBR), activated sludge and aeration processes among different biological processes. Surfactants, EDCs and personal care products (PCPs) can be well removed by activated sludge process. Pesticides and pharmaceuticals showed good removal efficiencies by biological activated carbon. Microalgae treatment processes can remove almost all types of ECs to some extent. Other biological processes were found less effective in ECs removal from wastewater. Chemical oxidation processes such as ozonation/H2O2, UV photolysis/H2O2 and photo-Fenton processes can successfully remove up to 100% of pesticides, beta blockers and pharmaceuticals, while EDCs can be better removed by ozonation and UV photocatalysis. Fenton process was found less effective in the removal of any types of ECs. A hybrid system based on ozonation followed by biological activated carbon was found highly efficient in the removal of pesticides, beta blockers and pharmaceuticals. A hybrid ozonation-ultrasound system can remove up to 100% of many pharmaceuticals. Future research directions to enhance the removal of ECs have been elaborated.
Belhaj, D, Frikha, D, Athmouni, K, Jerbi, B, Ahmed, MB, Bouallagui, Z, Kallel, M, Maalej, S, Zhou, J & Ayadi, H 2017, 'Box-Behnken design for extraction optimization of crude polysaccharides from Tunisian Phormidium versicolor cyanobacteria (NCC 466): Partial characterization, in vitro antioxidant and antimicrobial activities', INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES, vol. 105, pp. 1501-1510.View/Download from: UTS OPUS or Publisher's site
MB Ahmed, JunLiang Zhou, Huu Hao Nog, Wenshan Guo, MAH Johir, K. Sornalingram & MS Rahman 2017, 'Chloramphenicol interaction with functionalized biochar in water: sorptive mechanism, molecular imprinting effect and repeatable application', Science of the Total Environment, vol. 609, pp. 885-895.View/Download from: UTS OPUS or Publisher's site
Biochar and functionalized biochar (fBC-1 and fBC-2) were prepared and applied to remove antibiotic chloramphenicol
from deionized water, lake water and synthetic wastewater. Results showed that chloramphenicol removal
on biochar was pH dependent and maximum sorption occurred at pH 4.0–4.5. The sorption data of
chloramphenicol fitted better with the Langmuir isotherm model than the Freundlich isotherm model with the
maximum Langmuir sorption capacity of 233 μM g−1 using fBC-2. Chloramphenicol sorption on fBC-2 followed
the trend: deionized water N lake water N synthetic wastewater. The presence of humic acid decreased the
sorption distribution coefficient (Kd) while the presence of low ionic strength and soil in solution increased Kd
value significantly. The mechanism of sorption on fBC mainly involved electron-donor-acceptor (EDA) interactions
at pH b 2.0; formation of charge assisted hydrogen bond (CAHB) and hydrogen bonds in addition to EDA
in the pH 4.0–4.5; and CAHB and EDA interactions at pH N 7.0. Additionally, solvent and thermal regeneration
of fBC-2 for repeatable applications showed excellent sorption of chloramphenicol under the same condition,
due to the creation of a molecular imprinting effect in fBC-2. Consequently, fBC-2 can be applied with excellent
reusability properties to remove chloramphenicol and other similar organic contaminants.
Narottam Saha, M. Safiur Rahman, Ahmed, M, ZHou, Ngo & Guo 2017, 'Industrial metal pollution in water and probabilistic assessment of human health risk', Journal of Environmental Management, vol. 185, pp. 70-78.View/Download from: UTS OPUS or Publisher's site
Concentration of eight heavy metals in surface and groundwater around Dhaka Export Processing Zone
(DEPZ) industrial area were investigated, and the health risk posed to local children and adult residents
via ingestion and dermal contact was evaluated using deterministic and probabilistic approaches. Metal
concentrations (except Cu, Mn, Ni, and Zn) in Bangshi River water were above the drinking water quality
guidelines, while in groundwater were less than the recommended limits. Concentration of metals in
surface water decreased as a function of distance. Estimations of non-carcinogenic health risk for surface
water revealed that mean hazard index (HI) values of As, Cr, Cu, and Pb for combined pathways (i.e.,
ingestion and dermal contact) were >1.0 for both age groups. The estimated risk mainly came from the
ingestion pathway. However, the HI values for all the examined metals in groundwater were <1.0,
indicating no possible human health hazard. Deterministically estimated total cancer risk (TCR) via
Bangshi River water exceeded the acceptable limit of 1 104 for adult and children. Although, probabilistically
estimated 95th percentile values of TCR exceeded the benchmark, mean TCR values were less
than 1 104
. Simulated results showed that 20.13% and 5.43% values of TCR for surface water were
>1 104 for adult and children, respectively. Deterministic and probabilistic estimations of cancer risk
through exposure to groundwater were well below the safety limit. Overall, the population exposed to
Bangshi River water remained at carcinogenic and non-carcinogenic health threat and the risk was
higher for adults. Sensitivity analysis identified exposure duration (ED) and ingestion rate (IR) of water as
the most relevant variables affecting the probabilistic risk estimation model outcome.
Xu, B, Ahmed, MB, Zhou, JL, Altaee, A, Wu, M & Xu, G 2017, 'Photocatalytic removal of perfluoroalkyl substances from water and wastewater: Mechanism, kinetics and controlling factors.', Chemosphere, vol. 189, pp. 717-729.View/Download from: UTS OPUS or Publisher's site
This review focuses on heterogeneous photocatalysis of perfluoroalkyl substances (PFAS) which are of worldwide concern as emerging persistent organic contaminants. Heterogeneous photocatalysis is an effective and advanced technology for PFAS removal from water with relatively high efficacy. During photocatalysis, various short chain perfluorocarboxylic acids (PFCA) are produced as intermediates and the efficacy is related to the photo-generated hole (h+) and photo-generated electron (e-). PFAS photodegradation in water under UV irradiation is most effective by using In2O3 as the catalyst, followed by Ga2O3 and TiO2. Significantly, modifying the chemical composition or morphology of the catalyst can improve its efficacy for PFAS removal. In2O3 porous nanoplates were found to have the best performance of 100% PFAS decomposition under UV light with rate constant (kt) and half-time (τ1/2) of 0.158 min-1 and 4.4 min, respectively. Catalysts perform well in acidic solution and increasing temperature to a certain extent. The photocatalytic performance is reduced when treating wastewater due to the presence of dissolved organic matter (DOM), with the catalysts following the order: needle-like Ga2O3 > In2O3 > TiO2. Future studies should focus on the development of novel photocatalysts, and their immobilization and application for PFAS removal in wastewater.
Biochars (BCs) are widely produced and used for the remediation of environmental contaminants as bio-sorbents. In this review, statistical analysis of different BC physico–chemical properties was conducted. It was observed that woody materials are the most suitable for preparing BCs, among many other potential raw materials such as food wastes and agricultural materials. Currently BCs are produced through a variety of thermal treatment processes between 300 and 900 °C, among which slow pyrolysis is widely used due to its moderate operating conditions and optimization of BC yields. Hydrothermal carbonisation (HTC) is also an effective approach for BC production under certain conditions. As pyrolysis temperature is increased, the carbon content, ash content, surface area, and pore volume tend to be increased while the yield, hydrogen, oxygen, nitrogen content, and H/C and O/C molar ratios tend to decrease. The economic feasibility of BCs depends on a range of factors from raw material price to efficient production technologies. Thus, the overall cost equation of a pilot BC production plant together with the cost equation for BC regeneration has been proposed. The future research directions of BCs are also elaborated
Ahmed, MB, Zhou, JL, Ngo, HH, Guo, W & Chen, M 2016, 'Progress in the preparation and application of modified biochar for improved contaminant removal from water and wastewater', BIORESOURCE TECHNOLOGY, vol. 214, pp. 836-851.View/Download from: UTS OPUS or Publisher's site
Ahmed, MB, Hasan, ATMK, Mohiuddin, M, Asadullah, M, Rahman, MS & Khaleque, A 2016, 'Effects of heating rate and heating up time to central biomass particles for bio-oil production', Bangladesh Journal of Scientific and Industrial Research, vol. 51, no. 1, pp. 13-22.View/Download from: Publisher's site
Objective of this work was to pyrolysis woody biomass. Experiments were carried out at 300 to 500oC. Relatively bigger particles were used. Special emphasis was given to investigate the effects of heating rate and heating up time of the central mass of the particles on the product distribution. Surface temperature reached to the reactor set temperature immediately while the temperature at the central part was as low as 50oC. The center temperature gradually increased to the final temperature within 3 to 8 minutes, depending on the wood types and the reactor set temperature. For ipil-ipil wood the heating rate of the central mass was much faster than krishnachura and koroi woods, and thus the heating up time was lower. Ipil-ipil wood was experienced higher yield (65%) even at lower reactor temperature 300oC with particle temperature 450oC. In the case of krishnachura and koroi woods, the bio-oil yields were lower under the same condition due to the heating rates of the central parts were much slower. Further researchon different biomasses may be necessary to demonstrate overall process.Bangladesh J. Sci. Ind. Res. 51(1), 13-22, 2016
Ahmed, MB, Zhou, JL, Ngo, HH & Guo, W 2015, 'Adsorptive removal of antibiotics from water and wastewater: Progress and challenges', SCIENCE OF THE TOTAL ENVIRONMENT, vol. 532, pp. 112-126.View/Download from: UTS OPUS or Publisher's site
Asadullah, M, Jahan, I, Ahmed, MB, Adawiyah, P, Malek, NH & Rahman, MS 2014, 'Preparation of microporous activated carbon and its modification for arsenic removal from water', JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY, vol. 20, no. 3, pp. 887-896.View/Download from: UTS OPUS or Publisher's site
Asadullah, M, Kabir, MS, Ahmed, MB, Razak, NA, Rasid, NSA & Aezzira, A 2013, 'Role of microporosity and surface functionality of activated carbon in methylene blue dye removal from water', KOREAN JOURNAL OF CHEMICAL ENGINEERING, vol. 30, no. 12, pp. 2228-2234.View/Download from: Publisher's site
This study is aimed to be a contribution to climatic regionalization of Saudi Arabia. The study applies a multivariate factor-cluster analysis technique. The data used here have been obtained from 56 meteorological stations. The application of the technique is made into two stages. In the first stage, factor analysis alone is considered and its results in Saudi Arabia are discussed. In the second stage, the resultant factor scores are taken as an input in a cluster analysis process to obtain climatic regions. Thus the regions obtained in the second stage are a result of the integration of factor and cluster techniques. The results obtained by the technique are compared with those of some traditional methods. The factor-cluster analysis technique is found advantageous over many of those methods, as it produces richer regions and shows clear climate variations within this vast country.
Ekpe, J, Alexeenko, A, Zeid, A, Ahmed, B & Haddad, G 2008, 'Managing a successful exploration drilling campaign in Saudi Arabia: A case history', Society of Petroleum Engineers - 13th Abu Dhabi International Petroleum Exhibition and Conference, ADIPEC 2008, pp. 294-298.
The frontier exploration drilling campaign in the Kingdom of Saudi Arabia started in January 2006. LUKSAR, a joint venture between Lukoil and Aramco, took pragmatic approach to project management. Careful analysis of the campaign challenges included maximizing the local experience of service providers and proper planning to meet the drilling campaign targets. The first two wells have been drilled and tested successfully. The shortcomings of the first two wells were identified and resolved in wells three to five demonstrating significant improvement in performance. ©:2008, Society of Petroleum Engineers.