Academic literature on the topic 'Water;electrocoagulation. mechanisms;water treatment'
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Journal articles on the topic "Water;electrocoagulation. mechanisms;water treatment"
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Gali Aba Lulesa, Tofik, Dejene Beyene, Million Ebba, and Goshu Kenea. "Water Treatment Using Natural Coagulant and Electrocoagulation Process: A Comparison Study." International Journal of Analytical Chemistry 2022 (September 29, 2022): 1–11. http://dx.doi.org/10.1155/2022/4640927.
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Water treatment is the primary consideration before utilizing water for different purposes. Surface water is highly vulnerable to pollution, either due to natural or anthropogenic processes. The main targets of this study were to investigate surface water treatment using Moringa Oleifera (MO), the electrocoagulation process (EC), and the Moringa Oleifera assisted electrocoagulation process (MOAEC). The Moringa Oleifera, EC process, and Moringa Oleifera-assisted EC process are effective mechanisms for the removal of COD (Chemical Oxygen Demand), BOD (Biological Oxygen Demand), TDS (Total Dissolved Solids), phosphate, TSS (Total Suspended Solids), and color from surface water. Different operating parameters such as pH (5–11), the dosage of coagulant (0.2–0.5 g), contact time or reaction time (20–50 minutes), current (0.2–0.5 A), and settling time (5–20 minutes) were considered. The maximum removal efficiency using Moringa Oleifera and the EC process was COD (85.48%), BOD (78.50%), TDS (84.5%), phosphate (95.70%), TSS (93.90%), color (94.50%), and COD (90.50%), BOD (87%), TDS (97.50%), phosphate (89.10%), TSS (95.80%), and color (96.15%), respectively. Similarly, with the application of MOAEC, 91.47%, 89.35%, 97.0%, 90.20%, 9.10%, and 95.70% of COD, BOD, TDS, phosphate, TSS, and color were removed, respectively. The EC process and MOAEC were more effective in the removal of COD, BOD, TDS, TSS, and color than using MO. More phosphate was removed using MO than the EC process and MOAEC. Additionally, the effects of different operating parameters were studied on the removal efficiency.
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Smoczyński, L., H. Ratnaweera, M. Kosobucka, K. Kvaal, and M. Smoczyński. "Image analysis of sludge aggregates obtained at preliminary treatment of sewage." Water Science and Technology 70, no. 6 (July 28, 2014): 1048–55. http://dx.doi.org/10.2166/wst.2014.332.
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The results of wastewater treatment by Al and Fe salts and by electrocoagulation with aluminum electrodes are discussed and interpreted. Those processes used alone or combined with biological treatment, were analyzed for 50 and 90% removal of phosphates. Scanning electron microscopy (SEM) of the resulting sludge from three coagulation processes defined the perimeter P and area A of 129–142 differently sized objects in each contrast-enhanced image. Plots of lg A against lg P revealed that the analyzed sludge samples were made of self-similar aggregates–flocs with fractal characteristics. The slope of ‘log plots’ was used to determine surface fractal dimension Da, which was extrapolated to volumetric fractal dimension Dv. Dv was applied in a quantitative description of sludge aggregates–flocs. Aggregates–flocs of sludge obtained by Al ions (pre-polymerized Al and electrocoagulation) were characterized by higher values of Dv in comparison with sludge obtained by iron salts. The structure of {Al(OH)3} and {Fe(OH)3} aggregate–flocs was graphically simulated to determine the effect of size distribution and Dv on sweep flocculation and sludge separation and dehydration. Phosphate removal efficiency of 50% occurred at low ratios of Al:P and Fe:P. Adsorption-charge neutralization was suggested during coagulation with pre-polymerized coagulants, and sweep flow mechanism during electrocoagulation.
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Mousazadeh, Milad, S. Alizadeh, Zacharias Frontistis, Işık Kabdaşlı, Elnaz Karamati Niaragh, Zakaria Al Qodah, Zohreh Naghdali, et al. "Electrocoagulation as a Promising Defluoridation Technology from Water: A Review of State of the Art of Removal Mechanisms and Performance Trends." Water 13, no. 5 (February 28, 2021): 656. http://dx.doi.org/10.3390/w13050656.
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Fluoride ions present in drinking water are beneficial to human health when at proper concentration levels (0.5–1.5 mg L−1), but an excess intake of fluoride (>1.5 mg L−1) may pose several health problems. In this context, reducing high fluoride concentrations in water is a major worldwide challenge. The World Health Organization has recommended setting a permissible limit of 1.5 mg L−1. The application of electrocoagulation (EC) processes has received widespread and increasing attention as a promising treatment technology and a competitive treatment for fluoride control. EC technology has been favourably applied due to its economic effectiveness, environmental versatility, amenability of automation, and low sludge production. This review provides more detailed information on fluoride removal from water by the EC process, including operating parameters, removal mechanisms, energy consumption, and operating costs. Additionally, it also focuses attention on future trends related to improve defluoridation efficiency.
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Heffron, Joe, Brad McDermid, Emily Maher, Patrick J. McNamara, and Brooke K. Mayer. "Mechanisms of virus mitigation and suitability of bacteriophages as surrogates in drinking water treatment by iron electrocoagulation." Water Research 163 (October 2019): 114877. http://dx.doi.org/10.1016/j.watres.2019.114877.
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L.N, Ukiwe, Ibeneme S.I, Duru C.E, Okolue B.N, Onyedika G.O, and Nweze C.A. "Chemical and Electro-coagulation Techniques in Coagulation-Floccculation in Water and Wastewater Treatment- A Review." JOURNAL OF ADVANCES IN CHEMISTRY 9, no. 3 (December 1, 2013): 1988–99. http://dx.doi.org/10.24297/jac.v9i3.1006.
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Chemical and electrocoagulation are widely used coagulation methods employed in water and wastewater treatment. Both coagulation processes are effective in removing a wide range of impurities which include dissolved organic matter in form of chemical and biological oxygen demand, pathogens, oils, and colloidal particles as well as heavy metals. The present review has revealed that the mode of action of both coagulation methods is based on charge neutralization and floc formation. The effectiveness of both coagulation techniques depend on factors such as pH, coagulation dose, coagulant type, current density, applied voltage, water and wastewater type, type of electrode, as well as size and number of electrodes. The commonly used chemical coagulants are inorganic coagulants based on aluminum and iron salts. However, there have been considerable successes in the development of pre-hydrolyzed inorganic coagulants which have the added advantage over traditional inorganic coagulants in that they function well over a wide range of pH and water temperatures. Electrocoagulation has been proposed as an alternative method to chemical coagulation because it is environmental friendly and cheap to operate. Nonetheless, most researchers are of the opinion that there are still some uncertainties regarding the understanding of its optimal performance and design mechanism.
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Lam, Jillin Soo Ai, Noor Fazliani Shoparwe, Nurulbahiyah Ahmad Khairudin, Lian See Tan, and Kee Quen Lee. "Performance and Kinetic Study on Oil Removal Via Electrocoagulation Treatment." Journal of Physics: Conference Series 2129, no. 1 (December 1, 2021): 012068. http://dx.doi.org/10.1088/1742-6596/2129/1/012068.
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Abstract Electrocoagulation (EC) is a reliable technology for wastewater treatment. It has been applied in treating various source of wastewater from tannery, electroplating, dairy, textile processing, oil and oil-in-emulsion. It is crucial to strengthen the fundamental of the EC treatment on oily water sample for further studies. However, in depth studies on the performance of EC treatment on oily water sample is still requires in depth studies. In this research, a series of experiment has been conducted on the performance of EC treatment including effect of the amount of sodium chloride (NaCl), applied voltage and pH to determine the efficiency in oil removal. The EC treatment took placed in room temperature and constantly agitated for 30 minutes meanwhile samples were collected for every 5 minutes for UV–Vis analysis. Then, the efficiency of the treatment was determined followed by simulating the results in kinetic models. The highest efficiency of EC treatment was achieved with 89.26% of oil removal with the addition of 7.5g of NaCl, 4V of applied voltage and at pH 6. In addition, the results have better fitness towards pseudo second order (PSO) which indicates the mechanism of EC treatment is chemisorption.
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S, Yadav. "Advanced Techniques for Wastewater Treatment: A Review." Open Access Journal of Waste Management & Xenobiotics 2, no. 3 (2019): 1–11. http://dx.doi.org/10.23880/oajwx-16000126.
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Freshwater in lake and pond are often found to be polluted by heavy metals such as As, Zn, or Pb which are toxic in nature and non - biodegradable. Heavy metals are readily consumed by both aquatic flora and fauna present in the freshwater environment. It also polluted the air, water, and soil. Thus, they have adverse impact on the entire ecosystem. These heavy metals also enter the hum an systems through food consumed. This review discusses the methods and their mechanism used to reduce the amount of such heavy metals The methods which are in practice are Electrochemical Treatment (Electrocoagulation, Electro - Floatation, and Electro - Depo sition), Physicochemical Process (Chemical Precipitation, Ion - Exchange, and Adsorption), Membrane Filtration (Nanofiltration, Reverse Osmosis, Microfiltration, Ultrafiltration, and Electro - Dialysis),and Photo - Catalysis and Nanotechnology Treatment.
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Teng, Weiwei, Shijie Liu, Xin Zhang, Feng Zhang, Xianglu Yang, Mengxiao Xu, and Junwei Hou. "Reliability Treatment of Silicon in Oilfield Wastewater by Electrocoagulation." Water 15, no. 1 (January 3, 2023): 206. http://dx.doi.org/10.3390/w15010206.
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Scaling caused by silicate in oilfield wastewater gathering system pipelines can cause serious pipeline blockage. Therefore, this study adopts facile, effective and environment friendly electrocoagulation method to remove the silicon in oilfield wastewater. After confirming the level of factors through single factor experiments, the optimal scheme for electrocoagulation was selected by orthogonal experiments and verification tests, the silicon content would be dramatically decreased from 81.51 mg/L to 21.88 mg/L when pH = 6, reaction time = 20 min, current density = 27 mA/cm2 and wastewater temperature = 35 °C. In addition, the silicon removal rate would reach up to 85.90% when the pH of oilfield wastewater was kept as its original condition without changing other optimal factors; such an enhanced silicon removal effect could be attributed to the calcium ions chemical coagulation after the mechanism investigation.
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Snehi, Shivam, Hariraj Singh, Tanwi Priya, and Brijesh Kumar Mishra. "Understanding the natural organic matter removal mechanism from mine and surface water through the electrocoagulation method." Journal of Water Supply: Research and Technology-Aqua 68, no. 7 (October 14, 2019): 523–34. http://dx.doi.org/10.2166/aqua.2019.167.
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Abstract In the present study, the concept of ‘Sample alteration of surface water’ has been employed to improve the efficiency of the aluminum-based electrocoagulation (EC) treatment method for the removal of reactive fractions of natural organic matter (NOM) from chlorinated water. The characteristics of surface water have been slightly modified by adding mine water in different ratios. The process has been optimized using the response surface methodology (RSM) considering pH, current density, mix ratio, and contact time as factors. At the optimized condition, the EC method has significantly reduced total organic carbon, dissolved organic carbon (DOC), and UV254 absorbance values up to 24%, 27%, and 80%, respectively. The cumulative impact of sample alteration and EC method has exhibited outstanding coagulant activity in terms of UV254 abs, DOC, turbidity, phenol, and absorbance slope index (ASI) as well. A decrease in ASI values indicated the reduction of trihalomethane's formation in water-containing chlorine. This was validated by reduced chlorine demand. It can be concluded that mixing mine water with surface water can be a feasible and efficient method for treating water with a high NOM content.
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Xiao, Kunkun, Dongmei Huang, Chunli Kang, and Siyang Sun. "Removal of tetracyclines from aqueous solutions by electrocoagulation/pecan nutshell coupling processes: synergistic effect and mechanism." Water Science and Technology 82, no. 4 (August 5, 2020): 683–94. http://dx.doi.org/10.2166/wst.2020.367.
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Abstract The present work compared electrocoagulation (EC)/pecan shell (PS) coupling process with a simple electrocoagulation (EC) process for the removal of tetracyclines (TCs). The results indicated that the addition of appropriate PS could lead to the enhancement of the removal efficiency and decrease of operating time via synergistic influence, including conventional EC process, biomass materials adsorption, charge neutralization and coordination adsorption. The ideal condition for the coupling process was 2.5 mA/cm2 for current density and 3 cm for plate spacing. Based on the optimum condition, when the dosage of PS was 5 g/L, the initial concentration of tetracycline hydrochloride (TC), oxytetracycline hydrochloride (OTC) and chlortetracycline hydrochloride (CTC) was 250 mg/L, the removal rate of PS was 55.90%, 45.10% and 14.98% higher than those of EC process after 40 min treatment. In addition, compared to conventional EC process, the unit energy demand (UED) decreased by 49.62%, 53.2 4% and 26.35% and the unit electrode material demand (UEMD) decreased by 49.80%, 85.65% and 44.37%, respectively, which means more energy conservation and environmental protection.
Dissertations / Theses on the topic "Water;electrocoagulation. mechanisms;water treatment"
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Holt, Peter Kevin. "ELECTROCOAGULATION: UNRAVELLING AND SYNTHESISING THE MECHANISMS BEHIND A WATER TREATMENT PROCESS." Thesis, The University of Sydney, 2002. http://hdl.handle.net/2123/624.
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Electrocoagulation is an empirical (and largely heuristic) water treatment technology that has had many different applications over the last century. It has proven its viability by removing a wide range of pollutants. The approach to reactor design has been haphazard, however, with little or no reference to previous designs or underlying principles. This thesis reviewed these reactor designs, identifying key commonalities and synthesising a new design hierarchy, summarised by three main decisions: 1. Batch or continuous operation; 2. Coagulation only or coagulation plus flotation reactors, and; 3. Associated separation process if required. This design decision hierarchy thereby provides a consistent basis for future electrocoagulation reactor designs. Electrochemistry, coagulation, and flotation are identified as the key foundation sciences for electrocoagulation, and the relevant mechanisms (and their interactions) are extracted and applied in an electrocoagulation context. This innovative approach was applied to a 7 L batch electrocoagulation reactor treating clay-polluted water. Structured macroscopic experiments identified current (density), time, and mixing as the key operating parameters for electrocoagulation. A dynamic mass balance was conducted over the batch reactor, for the first time, thereby enabling the extraction of a concentration profile. For this batch system, three operating stages were then identifiable: lag, reactive, and stable stages. Each stage was systematically investigated (in contrast to the previous ad hoc approach) with reference to each of the foundation sciences and the key parameters of current and time. Electrochemical behaviour characterised both coagulant and bubble generation. Polarisation experiments were used to determine the rate-limiting step at each electrode's surface. Consequently the appropriate Tafel parameters were extracted and hence the cell potential. At low currents both electrodes (anode and cathode) operated in the charge-transfer region. As the current increased, the mechanism shifted towards the diffusion-limited region, which increased the required potential. Polarisation experiments also define the operating potential at each electrode thereby enabling aluminium's dissolution behaviour to be thermodynamically characterised on potential-pH (Pourbaix) diagrams. Active and passive regions were defined and hence the aluminium's behaviour in an aqueous environment can now be predicted for electrocoagulation. Novel and detailed solution chemistry modelling of the metastable and stable aluminium species revealed the importance of oligomer formation and their rates in electrocoagulation. In particular, formation of the positively trimeric aluminium species increased solution pH (to pH 10.6), beyond the experimentally observed operable pH of 9. Thereby signifying the importance of the formation kinetics to the trimer as the active coagulant specie in electrocoagulation. Further leading insights to the changing coagulation mechanism in electrocoagulation were possible by comparison and contrast with the conventional coagulation method of alum dosing. Initially in the lag stage, little aggregation is observed until the coagulant concentration reaches a critical level. Simultaneously, the measured zeta potential increases with coagulant addition and the isoelectric point is attained in the reactive stage. Here a sorption coagulation mechanism is postulated; probably charge neutralisation, that quickly aggregates pollutant particles forming open structured aggregates as indicated by the low fractal dimension. As time progresses, pollutant concentration decreases and aluminium addition continues hence aluminium hydroxide/oxide precipitates. The bubbles gently sweep the precipitate through the solution, resulting in coagulation by an enmeshment mechanism (sweep coagulation). Consequently compact aggregates are formed, indicating by the high fractal dimension. Flotation is an inherent aspect of the batch electrocoagulation reactor via the production of electrolytic gases. In the reactor, pollutant separation occurs in situ, either by flotation or settling. From the concentration profiles extracted, original kinetic expressions were formulated to quantify these competing removal processes. As current increases, both settling and flotation rate constants increased due to the additional coagulant generation. This faster removal was offset by a decrease in the coagulant efficiency. Consequently a trade-off exists between removal time and coagulant efficiency that can be evaluated economically. A conceptual framework of electrocoagulation is developed from the synthesis of the systematic study to enable a priori prediction. This framework creates predictability for electrocoagulation, which is innovative and original for the technology. Predictability provides insights to knowledge transfer (between batch and continuous), efficient coagulant and separation path, to name just a few examples. This predictability demystifies electrocoagulation by providing a powerful design tool for the future development of scaleable, industrial electrocoagulation water treatment design and operation process.
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Holt, Peter Kevin. "ELECTROCOAGULATION: UNRAVELLING AND SYNTHESISING THE MECHANISMS BEHIND A WATER TREATMENT PROCESS." University of Sydney. Chemical Engineering, 2003. http://hdl.handle.net/2123/624.
Full textAbstract:
Electrocoagulation is an empirical (and largely heuristic) water treatment technology that has had many different applications over the last century. It has proven its viability by removing a wide range of pollutants. The approach to reactor design has been haphazard, however, with little or no reference to previous designs or underlying principles. This thesis reviewed these reactor designs, identifying key commonalities and synthesising a new design hierarchy, summarised by three main decisions: 1. Batch or continuous operation; 2. Coagulation only or coagulation plus flotation reactors, and; 3. Associated separation process if required. This design decision hierarchy thereby provides a consistent basis for future electrocoagulation reactor designs. Electrochemistry, coagulation, and flotation are identified as the key foundation sciences for electrocoagulation, and the relevant mechanisms (and their interactions) are extracted and applied in an electrocoagulation context. This innovative approach was applied to a 7 L batch electrocoagulation reactor treating clay-polluted water. Structured macroscopic experiments identified current (density), time, and mixing as the key operating parameters for electrocoagulation. A dynamic mass balance was conducted over the batch reactor, for the first time, thereby enabling the extraction of a concentration profile. For this batch system, three operating stages were then identifiable: lag, reactive, and stable stages. Each stage was systematically investigated (in contrast to the previous ad hoc approach) with reference to each of the foundation sciences and the key parameters of current and time. Electrochemical behaviour characterised both coagulant and bubble generation. Polarisation experiments were used to determine the rate-limiting step at each electrode�s surface. Consequently the appropriate Tafel parameters were extracted and hence the cell potential. At low currents both electrodes (anode and cathode) operated in the charge-transfer region. As the current increased, the mechanism shifted towards the diffusion-limited region, which increased the required potential. Polarisation experiments also define the operating potential at each electrode thereby enabling aluminium�s dissolution behaviour to be thermodynamically characterised on potential-pH (Pourbaix) diagrams. Active and passive regions were defined and hence the aluminium�s behaviour in an aqueous environment can now be predicted for electrocoagulation. Novel and detailed solution chemistry modelling of the metastable and stable aluminium species revealed the importance of oligomer formation and their rates in electrocoagulation. In particular, formation of the positively trimeric aluminium species increased solution pH (to pH 10.6), beyond the experimentally observed operable pH of 9. Thereby signifying the importance of the formation kinetics to the trimer as the active coagulant specie in electrocoagulation. Further leading insights to the changing coagulation mechanism in electrocoagulation were possible by comparison and contrast with the conventional coagulation method of alum dosing. Initially in the lag stage, little aggregation is observed until the coagulant concentration reaches a critical level. Simultaneously, the measured zeta potential increases with coagulant addition and the isoelectric point is attained in the reactive stage. Here a sorption coagulation mechanism is postulated; probably charge neutralisation, that quickly aggregates pollutant particles forming open structured aggregates as indicated by the low fractal dimension. As time progresses, pollutant concentration decreases and aluminium addition continues hence aluminium hydroxide/oxide precipitates. The bubbles gently sweep the precipitate through the solution, resulting in coagulation by an enmeshment mechanism (sweep coagulation). Consequently compact aggregates are formed, indicating by the high fractal dimension. Flotation is an inherent aspect of the batch electrocoagulation reactor via the production of electrolytic gases. In the reactor, pollutant separation occurs in situ, either by flotation or settling. From the concentration profiles extracted, original kinetic expressions were formulated to quantify these competing removal processes. As current increases, both settling and flotation rate constants increased due to the additional coagulant generation. This faster removal was offset by a decrease in the coagulant efficiency. Consequently a trade-off exists between removal time and coagulant efficiency that can be evaluated economically. A conceptual framework of electrocoagulation is developed from the synthesis of the systematic study to enable a priori prediction. This framework creates predictability for electrocoagulation, which is innovative and original for the technology. Predictability provides insights to knowledge transfer (between batch and continuous), efficient coagulant and separation path, to name just a few examples. This predictability demystifies electrocoagulation by providing a powerful design tool for the future development of scaleable, industrial electrocoagulation water treatment design and operation process.
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Holt, Peter Kevin. "Electrocoagulation unravelling and synthesising the mechanisms behind a water treatment process /." Connect to full text, 2002. http://hdl.handle.net/2123/624.
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Thesis (Ph. D.)--University of Sydney, 2003.Title from title screen (viewed Apr. 28, 2008). Submitted in fulfilment of the requirements for the degree of Doctor of Philosophy to the Dept. of Chemical Engineering, Faculty of Engineering. Degree awarded 2003; thesis submitted 2002. Includes bibliography. Also available in print form.
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Gunukula, Sampath Reddy. "ELECTROCOAGULATION/FLOTATION TREATMENT OF SYNTHETIC SURFACE WATER." Cleveland State University / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=csu1304363574.
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Andrade, Milton. "Heavy metal removal from bilge water by electrocoagulation treatment." ScholarWorks@UNO, 2009. http://scholarworks.uno.edu/td/1092.
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The purpose of this research was to observe the removal efficiency for copper (Cu), nickel (Ni), and zinc (Zn) using Electrocoagulation (EC) technique in a continuous flow reactor with a synthetic bilge water emulsion; and additionally, to discuss the operation cost of the treatment. The optimal configuration for EC treatment used combined electrodes, aluminum and carbon steel; flow rate of 1 L/min; effluent recycling and 7.5 amps; this optimal configuration achieved 99% of zinc removal efficiency, 70% of both, copper and nickel removal efficiency, and low operation costs. The current intensity did not have significance incidence on the removal efficiency. The analysis of cost per gram of removed contaminant indicated that nickel had an average cost of $1.95 per gram removed, zinc and copper had $0.60 and $0.88 per gram removed, respectively. To develop additional experiments with the EC reactor are required in order to optimize metal removal efficiency.
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Lin, Jack. "Pre-treatment of coal seam water with coagulation and electrocoagulation." Thesis, Queensland University of Technology, 2017. https://eprints.qut.edu.au/105358/4/Jack_Lin_Thesis.pdf.
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This thesis examined innovative methods for pre-treatment of coal seam water. In order to prevent scaling and fouling of downstream reverse osmosis membranes we investigated both electrocoagulation and chemical coagulation using aluminium and iron based electrodes and/or coagulants. Application of electrocoagulation was found to significantly reduce the presence of problematic dissolved species such as silica and also alkaline earth ions which potentially can scale membranes and equipment. Chemical coagulation could also remove dissolved silica from simulated coal seam water samples but was found to be relatively ineffective when treating real coal seam water. The future study of electrocoagulation is worthy in order to determine its applicability to a wider range of coal seam water compositions and to minimise costs of use.
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Kuokkanen, V. (Ville). "Utilization of electrocoagulation for water and wastewater treatment and nutrient recovery:techno-economic studies." Doctoral thesis, Oulun yliopisto, 2016. http://urn.fi/urn:isbn:9789526211084.
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Abstract Electrocoagulation (EC) is an emerging technology that combines the functions and advantages of conventional coagulation, flotation, and electrochemistry in water and wastewater treatment. The aims of this work included doing an updated literary review of recent feasible applications of EC, which were found to be plentiful. Since the economic and practical operational key figures related to EC haven’t been extensively mapped out before, this was a prime objective of this part of the work. The aim of the next part of this work was to find new feasible applications for EC in the treatment of water and wastewater. The studied wastewaters included bio- and synthetic oil-in-water emulsions, various industrial nutrient-containing wastewaters, and peat bog drainage water containing humic substances (an interesting and topical problem, especially in Finland). These studies proved the feasibility of EC. In addition, larger-scale experiments were also conducted successfully, thus proving the scalability of the EC process. Extensive economic analyses of the studied EC applications were also done. The operational costs and energy consumption of EC were found to be very low—typically about 0.1–1.0 €/m3 and 0.4–4.0 kWh/m3. It has been forecasted that in the future there will be a shortage of virgin phosphorus. Therefore, another essential purpose of this work was to conduct a preliminary study on the feasibility of using EC for nutrient (especially phosphorus, but also nitrogen) removal and recovery from different types of real wastewater. Specifically, it may be possible to use EC sludges containing notable amounts of phosphorus and nitrogen as additives in granulated bio ash-based fertilizer products for various applications. This is a novel idea and a “hot topic” in the waste utilization sector and in circular and bioeconomyTiivistelmä Elektrokoagulaatio (electrocoagulation, EC) on nosteessa oleva teknologia, joka yhdistää perinteisen koagulaation, flotaation ja sähkökemian hyödyt ja mahdollisuudet vesien ja jätevesien käsittelyssä. Tämän työn ensimmäisenä tavoitteena oli laatia kirjallisuuskatsaus EC:n viimeaikaisista käyttökelpoisista sovelluksista, joita löytyi runsaasti. Koska EC:n toiminnallisia ja taloudellisia avainlukuja ei ole kartoitettu kattavasti aiemmin, tämän tekeminen oli tämän osion tärkein tavoite. Väitöstyön seuraavana tavoitteena oli löytää uusia sovellutuksia EC:lle vesien ja jätevesien käsittelyssä. Tutkittuja vesiä olivat bio- ja synteettisistä öljyistä valmistetut öljy-vesiemulsiot, erilaiset teolliset ravinnepitoiset jätevedet ja humusainepitoiset turvesoiden valumavedet (kiinnostava ja ajankohtainen ongelma, erityisesti Suomessa). EC todettiin käyttökelpoiseksi teknologiaksi näissä kokeissa. Suuremman skaalan kokeilla todistettiin lisäksi EC-prosessin skaalautuvuus. Lisäksi, em. EC-sovellutuksista suoritettiin kattavat taloudelliset analyysit. EC:n käyttökustannukset ja energiankulutus todettiin erittäin pieniksi, tyypillisesti ne olivat välillä 0.1–1.0 €/m3 ja 0.4–4.0 kWh/m3. On ennustettu, että tulevaisuudessa on pulaa neitseellisestä fosforista. Tästä johtuen eräs tämän työn keskeisistä tarkoituksista oli suorittaa alustavia kokeita liittyen EC:n käyttökelpoisuuteen ravinteiden (erityisesti fosfori, mutta myös typpi) poistossa ja talteenotossa aidoista jätevesistä. Erityisesti jatkossa voisi olla järkevää hyödyntää runsaasti fosforia ja typpeä sisältäviä EC-sakkoja lisäaineina rakeistetuissa biotuhkapohjaisissa lannoitteissa eri sovellutuksissa. Tämä idea on uusi ja on jo herättänyt suurta kiinnostusta mm. kierto- ja biotaloussektoreilla
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Willfors, Andreas. "Local Treatment of Water and Sludge Containing Oil in Sweden." Thesis, Mittuniversitetet, Avdelningen för ekoteknik och hållbart byggande, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:miun:diva-25146.
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Due to several reasons, treatment methods for a certain waste are oftennot available locally in the waste handling and management industry. This is especially true for regions which are not densely populated. This requires transports, the majority of which consumes fossil fuel. To avoid this, local waste treatment methods need to be developed. In this work it is investigated how treatment of one hazardous waste is done; water and sludge containing oil. Based on sustainability criteria three novel methods are presented that can be conducted locally; mycoremediation, phytoremediation and electrocoagulation. The methods are evaluated in a case study of a recycling company. Mycoremediation and electrocoagulation were found to be suitable in the case study, as long as some criteria are fulfilled. In addition it is shown what barriers exist in law, policies and practices that hinder local treatment of water and sludge containing oil.
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McBeath, Sean T. "Pilot capacity iron electrocoagulation scale-up for natural organic matter removal for drinking water treatment." Thesis, University of British Columbia, 2017. http://hdl.handle.net/2429/60562.
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Canadian remote communities are most often those who are affected by poor water quality and boil water advisories. A major issue is the applicability of traditional water treatment technologies to unconventional applications (small-scale and inaccessible communities). Their inaccessibility presents difficulties for supplying needed chemicals involved in traditional treatment processes such as coagulations and flocculation. Electrocoagulation (EC), an electrochemical process producing coagulant chemicals on-site and on-demand, may be an alternative technology to traditional coagulation suitable for small and remote communities. The following work investigated a continuous iron EC process for natural organic matter (NOM) removal. EC experiments were undertaken in the laboratory at 1.35 and 5 LPM, using synthetic surface water, monitoring the effect of flocculation, metal loading (ML), current density and inter-electrode gap. At both flow rates, flocculation was found to have no effect on the reduction of DOC or UV-abs-254. ML was found to have the greatest effect on both DOC and UV-abs-254 reductions, where the highest ML tested yielded reductions >90% and >60%, respectively. Increases in UV-abs-254 at low ML were found to be due to dissolved residual iron. It was determined that humic acid and chloride functioned as ligands and increased the solubility of iron. Operations were scaled-up to 10 LPM and integrated into a water treatment plant in the community of Van Anda, using raw surface water. Average DOC and UV-abs-254 reductions at the greatest ML were 37.2±4.2% and 54.7±0.9%, respectively. EC was found to have low energy requirements at a pilot-scale, whereby 0.480-0.621 kWh per cubic meter of water treated was required to operate at the conditions that yielded the greatest NOM reductions. Finally, an investigation to determine the current density distribution was undertaken. Current distribution results yielded increased current uniformity with the increase of the inter-electrode gap. This increased uniformity can be attributed to the water velocity profiles in the reactor. Through computational fluid dynamic (CFD) models, it was demonstrated that fluid flow uniformity also increased with an increasing inter-electrode gap. Regions of the electrode that were observed to be occupied by high fluid velocity were also areas yielding greater current density.Applied Science, Faculty of
Chemical and Biological Engineering, Department of
Graduate
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Peterson, Mark. "Electrodisinfection of Municipal Wastewater Effluent." ScholarWorks@UNO, 2005. http://scholarworks.uno.edu/td/294.
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To avoid the spread of disease from sewage treatment effluents, pathogenic microorganisms present must be destroyed by one or a combination of disinfection methods. Chlorine remains the predominant disinfectant used although it consumes considerable amounts of energy and has associated exposure risks from production, transportation and storage of this poisonous gas. In addition to bacteria and other objectionable microorganisms, color, suspended and colloidal solids also require removal from water for reuse. Aluminum and iron additions have been used to coagulate and remove non-settleable solids. By electrically dissolving aluminum to form solids-bridging aluminum hydroxide, the water itself can also be disinfected by the effects of electrical fields and its reactions to form disinfectant chemicals and direct destruction of microorganisms in the water. This research investigated the effects of electrical current, time, and chloride concentration on the electrochemical disinfection of sewage treatment plant effluent using aluminum electrodes to substitute for chlorine disinfection.
Books on the topic "Water;electrocoagulation. mechanisms;water treatment"
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Kadlec, R. H. Mechanisms of water quality improvement in wetland treatment systems. S.l: s.n, 1989.
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Kokuritsu Kankyō Kenkyūjo. Henshū Iinkai., ed. Biseibutsu o mochiita osen dojō, chikasui no jōka kikō ni kansuru kenkyū (tokubetsu kenkyū): Heisei 8--10-nendo = Studies on bioremediation mechanisms for contaminated soil and ground water : FY 1996--1998. Tsukuba-shi: Kankyōchō Kokuritsu Kankyō Kenkyūjo, 2000.
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F, Strom Peter, Littleton Helen X, Daigger Glen T, and Water Environment Research Foundation, eds. Characterizing mechanisms of simultaneous biological nutrient removal during wastewater treatment. Alexandria, VA: Water Environment Research Foundation, 2004.
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Strom, P. F., and H. X. Littleton. Characterizing Mechanisms of Simultaneous Biological Nutrient Removal During Wastewater Treatment. WERF, 2004.
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Boisson de Chazournes, Laurence. Fresh Water in International Law. 2nd ed. Oxford University Press, 2021. http://dx.doi.org/10.1093/oso/9780198863427.001.0001.
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This book, now in its second edition, addresses the diverse ways in which international law governs the uses, management, and protection of fresh water. The regulation of fresh water has primarily developed through the conclusion of treaties concerning international watercourses. Yet a number of other legal regimes also apply to the governance of fresh water. In particular, there has been an increasing recognition of the importance of fresh water to environmental protection. The development of international human rights law and international humanitarian law has also proven crucial for ensuring the sound and equitable management of this resource. In addition, the economic uses of fresh water feature prominently in the law applicable to watercourses and other sources of water, while water itself has become an important element of the trade and investment regimes. These bodies of rules and principles not only surface in an array of dispute settlement mechanisms, but also stimulate wider trends of institutionalization. The book investigates the origin and scope of these bodies of norms as they apply to fresh water, and demonstrates how they connect and adapt to one another, forming an integrated body of international principles. This approach is accompanied by a detailed analysis of the practice of states and of international organizations, taking into account the activities of the many non-state actors involved in the treatment of fresh water, and of the many jurisdictions which have been confronted with water issues.
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Zrazhevskiy, P., and X. Gao. Bioconjugated quantum dots for tumor molecular imaging and profiling. Edited by A. V. Narlikar and Y. Y. Fu. Oxford University Press, 2017. http://dx.doi.org/10.1093/oxfordhb/9780199533060.013.17.
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This article discusses the use of bioconjugated quantum dots (QDs) for tumor molecular imaging and profiling. The need for personalized diagnostics and therapy is becoming apparent in all areas of medicine, and especially urgent and sought after in treating cancer. Mechanisms of cancerogenesis and cancer response to therapy remain poorly understood, thus precluding accurate cancer diagnosis, prognosis, and effective treatment. Accurate molecular profiling of individual tumors is one key to effective treatment. This article first considers the photophysical properties of QDs before reviewing the most common methods for engineering QD-based probes for biomedical applications, including water solubilization and bioconjugation approaches. It also describes a number of techniques for molecular imagingand profiling of tumors, ranging from QD-based multicolor flow cytometry and applications of QDs in high-resolution correlated fluorescence/electron microscopy, QD bioprobes for molecular profiling of tumor-tissue sections and microarrays, and QD-oligonucleotide bioconjugates for in-situ hybridization.
Book chapters on the topic "Water;electrocoagulation. mechanisms;water treatment"
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Liu, Huijuan, Xu Zhao, and Jiuhui Qu. "Electrocoagulation in Water Treatment." In Electrochemistry for the Environment, 245–62. New York, NY: Springer New York, 2009. http://dx.doi.org/10.1007/978-0-387-68318-8_10.
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Makwana, Abhipsa R. "Factors Influencing Electrocoagulation Treatment of UASB Reactor Effluent." In Water Science and Technology Library, 55–64. Singapore: Springer Singapore, 2018. http://dx.doi.org/10.1007/978-981-10-5795-3_5.
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Hashim, Khalid S., Rafid AlKhaddar, Andy Shaw, P. Kot, Dhiya Al-Jumeily, Reham Alwash, and Mohammed Hashim Aljefery. "Electrocoagulation as an Eco-Friendly River Water Treatment Method." In Lecture Notes in Civil Engineering, 219–35. Singapore: Springer Singapore, 2019. http://dx.doi.org/10.1007/978-981-13-8181-2_17.
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Safonyk, Andrii, Andrii Bomba, and Ivan Tarhonii. "Modeling and Automation of the Electrocoagulation Process in Water Treatment." In Advances in Intelligent Systems and Computing, 451–63. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-030-01069-0_32.
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Thakur, Sandeep, and M. S. Chauhan. "Treatment of Dye Wastewater from Textile Industry by Electrocoagulation and Fenton Oxidation: A Review." In Water Science and Technology Library, 117–29. Singapore: Springer Singapore, 2018. http://dx.doi.org/10.1007/978-981-10-5795-3_11.
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Ratnaweera, Harsha, Joachim Fettig, and Hallvard Ødegaard. "Particle and Phosphate Removal Mechanisms with Prepolymerized Coagulants." In Chemical Water and Wastewater Treatment II, 3–17. Berlin, Heidelberg: Springer Berlin Heidelberg, 1992. http://dx.doi.org/10.1007/978-3-642-77827-8_1.
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Rajemahadik, Chandrasen, Sunil Shah, Vinayak Desai, Shubham Kurlapkar, Akash Gambhire, Vikrant Patil, and Jaykumar Trambadia. "Efficient Diminution of Cr(VI) from Simulated Water Linking Operation Parameters in Electrocoagulation." In Environmental Degradation: Monitoring, Assessment and Treatment Technologies, 127–49. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-94148-2_11.
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Fujiwara, Masatoshi, and Yaichi Aoshima. "The Increasing Demand for Water Treatment and Reverse Osmosis." In Mechanisms for Long-Term Innovation, 25–38. Singapore: Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-19-4896-1_2.
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Nidheesh, P. V., Ansaf V. Karim, T. S. Anantha Singh, Dhanashree Dofe, Sheetal Sahare, and M. Suresh Kumar. "Mechanism of Treatment Methods of Arsenic-Contaminated Water." In Mechanisms of Arsenic Toxicity and Tolerance in Plants, 405–55. Singapore: Springer Singapore, 2018. http://dx.doi.org/10.1007/978-981-13-1292-2_17.
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Kuratli, J., H. Marti, C. Blenn, and N. Borel. "Water-Filtered Infrared A (wIRA) Irradiation: Novel Treatment Options for Chlamydial Infections." In Water-filtered Infrared A (wIRA) Irradiation, 247–57. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-92880-3_21.
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AbstractwIRA has been shown to reduce extracellular chlamydial forms and intracellular chlamydial inclusions in different cell culture infection models, and similarly on different human or animal chlamydial species. Repeated wIRA applications increase the efficacy of treatment in vitro, and in vivo in a guinea pig ocular model of inclusion conjunctivitis. The guinea pig model reflects the human ocular disease trachoma, the most common cause of infectious blindness worldwide which is caused by ocular strains of Chlamydia trachomatis. In this model, ocular wIRA treatment reduces conjunctival chlamydial load and ocular pathology. First insights into the mechanisms of anti-chlamydial activity indicate the involvement of both thermal and non-thermal effects. Interestingly, wIRA treatment of non-infected cells renders them more resistant to subsequent chlamydial infection, suggesting cell-related mechanisms that might involve cytochrome C. Further studies envisage the refinement of wIRA treatment protocols, the enhancement of anti-chlamydial activity by adding photodynamic substances, and characterization of the mechanisms underlying the therapeutic benefit of wIRA.
Conference papers on the topic "Water;electrocoagulation. mechanisms;water treatment"
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Li, Xiangdong, Qiyan Feng, Qingjun Meng, and Yujie Ceng. "Electrocoagulation for the Drinking Water Treatment of Polluted Surface Water Supplies." In 2008 2nd International Conference on Bioinformatics and Biomedical Engineering (ICBBE '08). IEEE, 2008. http://dx.doi.org/10.1109/icbbe.2008.1103.
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"Water Treatment by Electrocoagulation, Sorption and Photocatalytic Oxidation." In April 18-19, 2017 Kyoto (Japan). DiRPUB, 2017. http://dx.doi.org/10.15242/dirpub.dir0417248.
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Pop, A., C. Bordianu, R. Pode, I. Vlaicu, N. Lungar, K. Bodor, and F. Manea. "Drinking water treatment by iron anode-based electrocoagulation: humic acids and arsenic removal." In WATER POLLUTION 2016. Southampton UK: WIT Press, 2016. http://dx.doi.org/10.2495/wp160121.
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Soeprijanto, Adela Dea Perdani, Dennis Farina Nury, and Lily Pudjiastuti. "Treatment of oily bilge water by electrocoagulation process using aluminum electrodes." In INTERNATIONAL SEMINAR ON FUNDAMENTAL AND APPLICATION OF CHEMICAL ENGINEERING 2016 (ISFAChE 2016): Proceedings of the 3rd International Seminar on Fundamental and Application of Chemical Engineering 2016. Author(s), 2017. http://dx.doi.org/10.1063/1.4982345.
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Nugroho, F. A., P. T. P. Aryanti, S. Nurhayati, and H. M. Muna. "A combined electrocoagulation and mixing process for contaminated river water treatment." In THE 4TH INTERNATIONAL CONFERENCE ON INDUSTRIAL, MECHANICAL, ELECTRICAL, AND CHEMICAL ENGINEERING. Author(s), 2019. http://dx.doi.org/10.1063/1.5098192.
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Younker, J., S. Y. Lee, Graham Gagnon, and M. E. Walsh. "Atlantic Canada Offshore R&D: Treatment of Oilfield Produced Water by Chemical Coagulation and Electrocoagulation." In Offshore Technology Conference. Offshore Technology Conference, 2011. http://dx.doi.org/10.4043/22003-ms.
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Feng, Qiyan, Ping Lu, Xiangdong Li, Qingjun Meng, and Yue Sun. "Electrocoagulation-Microfiltration for Drinking Water Treatment: A Case Study with the Typical Micro-Polluted Source Waters." In 2009 3rd International Conference on Bioinformatics and Biomedical Engineering (iCBBE 2009). IEEE, 2009. http://dx.doi.org/10.1109/icbbe.2009.5162764.
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Sutanto and Rahmat. "Effect of Addition of Sea Water on Changes in Turbidity and Metal Content in Industrial Wastewater Treatment into Drinking Water using Electrocoagulation Process." In Annual Southeast Asian International Seminar. SCITEPRESS - Science and Technology Publications, 2020. http://dx.doi.org/10.5220/0010536000850092.
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Islam, M. R., and A. Chakma. "Mechanisms And Process Selection Criteria For Waste Water Treatment In Petroleum Production." In Annual Technical Meeting. Petroleum Society of Canada, 1989. http://dx.doi.org/10.2118/89-40-90.
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U, Ayyappan, Indu M.S, Adithya G. Murickan, Balagopal J, Arun S. Kumar, and Priya K L. "Continuous flow electrocoagulation system for the treatment of coir industry wastewater." In International Web Conference in Civil Engineering for a Sustainable Planet. AIJR Publisher, 2021. http://dx.doi.org/10.21467/proceedings.112.29.
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Coir industry, a prominent industry in Kerala, uses huge amount of water and chemical reagents for its functioning. The effluent from these industries has high BOD, COD, toxic chemicals, oils and grease etc. Of the various pollutants, synthetic dyes are the most concerning. Electrocoagulation has advantages over other systems, as it doesn’t produce any secondary pollutants. In this study, a continuous flow electrocoagulation reactor is designed and operational parameters like flow rate, voltage, pH, electrolyte concentration, dye concentration and electrode orientation are optimized. The influence of these parameters are assessed by measuring colour removal efficiency (CRE) and chemical oxygen demand (COD). The optimum flow, voltage, electrolyte concentration, pH and electrode orientation were 1000 mL/hr., 8V, 1000 mg/L, 7 and parallel respectively. The optimized parameters were used for performance evaluation of the system in treating coir industry wastewater. Under these optimized conditions, colour removal efficiency, turbidity, pH, COD removal efficiency and BOD removal efficiency for the treated coir industry wastewater was found as 92.17%, 25 NTU, 8.7, 95.49%, and 92.20% respectively.
Reports on the topic "Water;electrocoagulation. mechanisms;water treatment"
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Desiderati, Christopher. Carli Creek Regional Water Quality Project: Assessing Water Quality Improvement at an Urban Stormwater Constructed Wetland. Portland State University, 2022. http://dx.doi.org/10.15760/mem.78.
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Stormwater management is an ongoing challenge in the United States and the world at-large. As state and municipal agencies grapple with conflicting interests like encouraging land development, complying with permits to control stormwater discharges, “urban stream syndrome” effects, and charges to steward natural resources for the long-term, some agencies may turn to constructed wetlands (CWs) as aesthetically pleasing and functional natural analogs for attenuating pollution delivered by stormwater runoff to rivers and streams. Constructed wetlands retain pollutants via common physical, physicochemical, and biological principles such as settling, adsorption, or plant and algae uptake. The efficacy of constructed wetlands for pollutant attenuation varies depending on many factors such as flow rate, pollutant loading, maintenance practices, and design features. In 2018, the culmination of efforts by Clackamas Water Environment Services and others led to the opening of the Carli Creek Water Quality Project, a 15-acre constructed wetland adjacent to Carli Creek, a small, 3500-ft tributary of the Clackamas River in Clackamas County, OR. The combined creek and constructed wetland drain an industrialized, 438-acre, impervious catchment. The wetland consists of a linear series of a detention pond and three bioretention treatment cells, contributing a combined 1.8 acres of treatment area (a 1:243 ratio with the catchment) and 3.3 acre-feet of total runoff storage. In this study, raw pollutant concentrations in runoff were evaluated against International Stormwater BMP database benchmarks and Oregon Water Quality Criteria. Concentration and mass-based reductions were calculated for 10 specific pollutants and compared to daily precipitation totals from a nearby precipitation station. Mass-based reductions were generally higher for all pollutants, largely due to runoff volume reduction on the treatment terrace. Concentration-based reductions were highly variable, and suggested export of certain pollutants (e.g., ammonia), even when reporting on a mass-basis. Mass load reductions on the terrace for total dissolved solids, nitrate+nitrite, dissolved lead, and dissolved copper were 43.3 ± 10%, 41.9 ± 10%, 36.6 ± 13%, and 43.2 ± 16%, respectively. E. coli saw log-reductions ranging from -1.3 — 3.0 on the terrace, and -1.0 — 1.8 in the creek. Oregon Water Quality Criteria were consistently met at the two in-stream sites on Carli Creek for E. coli with one exception, and for dissolved cadmium, lead, zinc, and copper (with one exception for copper). However, dissolved total solids at the downstream Carli Creek site was above the Willamette River guidance value 100 mg/L roughly 71% of the time. The precipitation record during the study was useful for explaining certain pollutant reductions, as several mechanisms are driven by physical processes, however it was not definitive. The historic rain/snow/ice event in mid-February 2021 appeared to impact mass-based reductions for all metals. Qualitatively, precipitation seemed to have the largest effect on nutrient dynamics, specifically ammonia-nitrogen. Determining exact mechanisms of pollutant removals was outside the scope of this study. An improved flow record, more targeted storm sampling, or more comprehensive nutrient profiles could aid in answering important questions on dominant mechanisms of this new constructed wetland. This study is useful in establishing a framework and baseline for understanding this one-of-a-kind regional stormwater treatment project and pursuing further questions in the future.
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Litaor, Iggy, James Ippolito, Iris Zohar, and Michael Massey. Phosphorus capture recycling and utilization for sustainable agriculture using Al/organic composite water treatment residuals. United States Department of Agriculture, January 2015. http://dx.doi.org/10.32747/2015.7600037.bard.
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Objectives: 1) develop a thorough understanding of the sorption mechanisms of Pi and Po onto the Al/O- WTR; 2) determine the breakthrough range of the composite Al/O-WTR during P capturing from agro- wastewaters; and 3) critically evaluate the performance of the composite Al/O-WTR as a fertilizer using selected plants grown in lysimeters and test-field studies. Instead of lysimeters we used pots (Israel) and one- liter cone-tainers (USA). We conducted one field study but in spite of major pretreatments the soils still exhibited high enough P from previous experiments so no differences between control and P additions were noticeable. Due to time constrains the field study was discontinued. Background: Phosphorous, a non-renewable resource, has been applied extensively in fields to increase crop yield, yet consequently has increased the potential of waterway eutrophication. Our proposal impetus is the need to develop an innovative method of P capturing, recycling and reuse that will sustain agricultural productivity while concurrently reducing the level of P discharge from and to agricultural settings. Major Conclusions & Achievements: An innovative approach was developed for P removal from soil leachate, dairy wastewater (Israel), and swine effluents (USA) using Al-based water treatment residuals (Al- WTR) to create an organic-Al-WTR composite (Al/O-WTR), potentially capable of serving as a P fertilizer source. The Al-WTR removed 95% inorganic-P, 80% to 99.9% organic P, and over 60% dissolved organic carbon from the agro-industrial waste streams. Organic C accumulation on particles surfaces possibly enhanced weak P bonding and facilitated P desorption. Analysis by scanning electron microscope (SEM- EDS), indicated that P was sparsely sorbed on both calcic and Al (hydr)oxide surfaces. Sorption of P onto WW-Al/O-WTR was reversible due to weak Ca-P and Al-P bonds induced by the slight alkaline nature and in the presence of organic moieties. Synchrotron-based microfocused X-ray fluorescence (micro-XRF) spectrometry, bulk P K-edge X-ray absorption near edge structure spectroscopy (XANES), and P K-edge micro-XANES spectroscopy indicated that adsorption was the primary P retention mechanism in the Al- WTR materials. However, distinct apatite- or octocalciumphosphatelike P grains were also observed. Synchrotron micro-XRF mapping further suggested that exposure of the aggregate exteriors to wastewater caused P to diffuse into the porous Al-WTR aggregates. Organic P species were not explicitly identified via P K-edge XANES despite high organic matter content, suggesting that organic P may have been predominantly associated with mineral surfaces. In screen houses experiments (Israel) we showed that the highest additions of Al/O-WTR (5 and 7 g kg⁻¹) produced the highest lettuce (Lactuca sativa L. var. longifolial) yield. Lettuce yield and P concentration were similar across treatments, indicating that Al/O- WTR can provide sufficient P to perform similarly to common fertilizers. A greenhouse study (USA) was utilized to compare increasing rates of swine wastewater derived Al/O-WTR and inorganic P fertilizer (both applied at 33.6, 67.3, and 134.5 kg P₂O₅ ha⁻¹) to supply plant-available P to spring wheat (TriticumaestivumL.) in either sandy loam or sandy clay loam soil. Spring wheat straw and grain P uptake were comparable across all treatments in the sandy loam, while Al/O-WTR application to the sandy clay loam reduced straw and grain P uptake. The Al/O-WTR did not affect soil organic P concentrations, but did increase phosphatase activity in both soils; this suggests that Al/O-WTR application stimulated microorganisms and enhance the extent to which microbial communities can mineralize Al/O-WTR-bound organic P. Implications: Overall, results suggest that creating a new P fertilizer from Al-WTR and agro-industrial waste sources may be a feasible alternative to mining inorganic P fertilizer sources, while protecting the environment from unnecessary waste disposal.
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Husson, Scott M., Viatcheslav Freger, and Moshe Herzberg. Antimicrobial and fouling-resistant membranes for treatment of agricultural and municipal wastewater. United States Department of Agriculture, January 2013. http://dx.doi.org/10.32747/2013.7598151.bard.
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This research project introduced a novel membrane coating strategy to combat biofouling, which is a major problem for the membrane-based treatment of agricultural and municipal wastewaters. The novelty of the strategy is that the membrane coatings have the unique ability to switch reversibly between passive (antifouling) and active (antimicrobial) fouling control mechanisms. This dual-mode approach differs fundamentally from other coating strategies that rely solely on one mode of fouling control. The research project had two complementary objectives: (1) preparation, characterization, and testing of dual-mode polymer nanolayers on planar surfaces and (2) evaluation of these nanolayers as membrane modifiers. The first objective was designed to provide a fundamental understanding of how polymer nanolayer chemistry and structure affect bacterial deposition and to demonstrate the reversibility of chemical switching. The second objective, which focused on membrane development, characterization, and testing, was designed to demonstrate methods for the production of water treatment membranes that couple passive and active biofouling control mechanisms. Both objectives were attained through synergistic collaboration among the three research groups. Using planar silicon and glass surfaces, we demonstrated using infrared spectroscopy that this new polymer coating can switch reversibly between the anti-fouling, zwitterion mode and an anti-microbial, quaternary amine mode. We showed that switching could be done more than 50 times without loss of activity and that the kinetics for switching from a low fouling zwitterion surface to an antimicrobial quaternary amine surface is practical for use. While a low pH was required for switching in the original polymer, we illustrated that by slightly altering the chemistry, it is possible to adjust the pH at which the switching occurs. A method was developed for applying the new zwitterionic surface chemistry onto polyethersulfone (PES) ultrafiltration membranes. Bacteria deposition studies showed that the new chemistry performed better than other common anti-fouling chemistries. Biofilm studies showed that PESultrafiltration membranes coated with the new chemistry accumulated half the biomass volume as unmodified membranes. Biofilm studies also showed that PES membranes coated with the new chemistry in the anti-microbial mode attained higher biofilm mortality than PES membranes coated with a common, non-switchablezwitterionic polymer. Results from our research are expected to improve membrane performance for the purification of wastewaters prior to use in irrigation. Since reduction in flux due to biofouling is one of the largest costs associated with membrane processes in water treatment, using dual-mode nanolayer coatings that switch between passive and active control of biofouling and enable detachment of attached biofoulants would have significant economic and societal impacts. Specifically, this research program developed and tested advanced ultrafiltration membranes for the treatment of wastewaters. Such membranes could find use in membrane bioreactors treating municipal wastewater, a slightly upgraded version of what presently is used in Israel for irrigation. They also may find use for pretreatment of agricultural wastewaters, e.g., rendering facility wastewater, prior to reverse osmosis for desalination. The need to desalinate such impaired waters water for unlimited agricultural use is likely in the near future.
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Or, Etti, David Galbraith, and Anne Fennell. Exploring mechanisms involved in grape bud dormancy: Large-scale analysis of expression reprogramming following controlled dormancy induction and dormancy release. United States Department of Agriculture, December 2002. http://dx.doi.org/10.32747/2002.7587232.bard.
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The timing of dormancy induction and release is very important to the economic production of table grape. Advances in manipulation of dormancy induction and dormancy release are dependent on the establishment of a comprehensive understanding of biological mechanisms involved in bud dormancy. To gain insight into these mechanisms we initiated the research that had two main objectives: A. Analyzing the expression profiles of large subsets of genes, following controlled dormancy induction and dormancy release, and assessing the role of known metabolic pathways, known regulatory genes and novel sequences involved in these processes B. Comparing expression profiles following the perception of various artificial as well as natural signals known to induce dormancy release, and searching for gene showing similar expression patterns, as candidates for further study of pathways having potential to play a central role in dormancy release. We first created targeted EST collections from V. vinifera and V. riparia mature buds. Clones were randomly selected from cDNA libraries prepared following controlled dormancy release and controlled dormancy induction and from respective controls. The entire collection (7920 vinifera and 1194 riparia clones) was sequenced and subjected to bioinformatics analysis, including clustering, annotations and GO classifications. PCR products from the entire collection were used for printing of cDNA microarrays. Bud tissue in general, and the dormant bud in particular, are under-represented within the grape EST database. Accordingly, 59% of the our vinifera EST collection, composed of 5516 unigenes, are not included within the current Vitis TIGR collection and about 22% of these transcripts bear no resemblance to any known plant transcript, corroborating the current need for our targeted EST collection and the bud specific cDNA array. Analysis of the V. riparia sequences yielded 814 unigenes, of which 140 are unique (keilin et al., manuscript, Appendix B). Results from computational expression profiling of the vinifera collection suggest that oxidative stress, calcium signaling, intracellular vesicle trafficking and anaerobic mode of carbohydrate metabolism play a role in the regulation and execution of grape-bud dormancy release. A comprehensive analysis confirmed the induction of transcription from several calcium–signaling related genes following HC treatment, and detected an inhibiting effect of calcium channel blocker and calcium chelator on HC-induced and chilling-induced bud break. It also detected the existence of HC-induced and calcium dependent protein phosphorylation activity. These data suggest, for the first time, that calcium signaling is involved in the mechanism of dormancy release (Pang et al., in preparation). We compared the effects of heat shock (HS) to those detected in buds following HC application and found that HS lead to earlier and higher bud break. We also demonstrated similar temporary reduction in catalase expression and temporary induction of ascorbate peroxidase, glutathione reductase, thioredoxin and glutathione S transferase expression following both treatments. These findings further support the assumption that temporary oxidative stress is part of the mechanism leading to bud break. The temporary induction of sucrose syntase, pyruvate decarboxylase and alcohol dehydrogenase indicate that temporary respiratory stress is developed and suggest that mitochondrial function may be of central importance for that mechanism. These finding, suggesting triggering of identical mechanisms by HS and HC, justified the comparison of expression profiles of HC and HS treated buds, as a tool for the identification of pathways with a central role in dormancy release (Halaly et al., in preparation). RNA samples from buds treated with HS, HC and water were hybridized with the cDNA arrays in an interconnected loop design. Differentially expressed genes from the were selected using R-language package from Bioconductor project called LIMMA and clones showing a significant change following both HS and HC treatments, compared to control, were selected for further analysis. A total of 1541 clones show significant induction, of which 37% have no hit or unknown function and the rest represent 661 genes with identified function. Similarly, out of 1452 clones showing significant reduction, only 53% of the clones have identified function and they represent 573 genes. The 661 induced genes are involved in 445 different molecular functions. About 90% of those functions were classified to 20 categories based on careful survey of the literature. Among other things, it appears that carbohydrate metabolism and mitochondrial function may be of central importance in the mechanism of dormancy release and studies in this direction are ongoing. Analysis of the reduced function is ongoing (Appendix A). A second set of hybridizations was carried out with RNA samples from buds exposed to short photoperiod, leading to induction of bud dormancy, and long photoperiod treatment, as control. Analysis indicated that 42 genes were significant difference between LD and SD and 11 of these were unique.
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Chefetz, Benny, and Jon Chorover. Sorption and Mobility of Pharmaceutical Compounds in Soils Irrigated with Treated Wastewater. United States Department of Agriculture, 2006. http://dx.doi.org/10.32747/2006.7592117.bard.
Full textAbstract:
Research into the fate of pharmaceutical compounds (PCs) in the environment has focused on aspects of removal efficiency during sewage treatment, degradation in surface water and accumulation in soils and sediments. However, very little information is available on the binding interactions of pharmaceuticals with dissolved organic matter (DOM) originating from wastewater treatment. Such interactions can significantly affect the transport potential of PCs in soils by altering compound affinity for soil particle surfaces. Our primary hypothesis is that the transport potential of PCs in soils is strongly impacted by the type and strength of interaction with DOM and the stability of resulting DOM-PC complexes. The overarching goal of the proposed work is to develop a better understanding of the risk associated with introduction of PCs into the environment with treated wastewater. This goal has been achieved by elucidating the mechanisms of the interaction of selected pharmaceuticals (that have shown to be widespread wastewater contaminants) with DOM constituents; by determining the stability and fate of DOM-PC complexes introduced to soils and soil constituents; and by evaluating the potential uptake of these compounds by plants. Based on the results obtained in this study (column and batch sorption-desorption experiments), we suggest that PCs can be classified as slow-mobile compounds in SOM-rich soil layers. When these compounds pass this layer and/or are introduced into SOM-poor soils, their mobility increases significantly. Our data suggest that in semiarid soils (consisting of low SOM), PCs can potentially be transported to the groundwater in fields irrigated with reclaimed wastewater. Moreover, the higher mobility of the acid PCs (i.e., naproxen and diclofenac) in freshwater column systems suggests that their residues in soils irrigated with reclaimed wastewater can leach from the root zone and be transported to the groundwater after rain events. Our data obtained from the binding experiments of PCs with DOM demonstrate that the hydrophobic DOM fractions were more efficient at sorbing PCs than the more polar hydrophilic fractions at a pH near the pKa of the analytes. At the pH of natural semiarid water and soil systems, including that of reclaimed wastewater and biosolids, the role of the hydrophobic fractions as sorption domains is less important than the contribution of the hydrophilic fractions. We also hypothesize that the DOM fractions interact with each other at the molecular level and do not act as independent sorption domains. In summary, our data collected in the BARD project demonstrate that the sorption abilities of the DOM fractions can also significantly affect the mobility of pharmaceutical compounds in soils influenced by intensive irrigation with treated wastewater or amended with biosolids.
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Chefetz, Benny, and Jon Chorover. Sorption and Mobility of Pharmaceutical Compounds in Soils Irrigated with Treated Wastewater. United States Department of Agriculture, 2006. http://dx.doi.org/10.32747/2006.7709883.bard.
Full textAbstract:
Research into the fate of pharmaceutical compounds (PCs) in the environment has focused on aspects of removal efficiency during sewage treatment, degradation in surface water and accumulation in soils and sediments. However, very little information is available on the binding interactions of pharmaceuticals with dissolved organic matter (DOM) originating from wastewater treatment. Such interactions can significantly affect the transport potential of PCs in soils by altering compound affinity for soil particle surfaces. Our primary hypothesis is that the transport potential of PCs in soils is strongly impacted by the type and strength of interaction with DOM and the stability of resulting DOM-PC complexes. The overarching goal of the proposed work is to develop a better understanding of the risk associated with introduction of PCs into the environment with treated wastewater. This goal has been achieved by elucidating the mechanisms of the interaction of selected pharmaceuticals (that have shown to be widespread wastewater contaminants) with DOM constituents; by determining the stability and fate of DOM-PC complexes introduced to soils and soil constituents; and by evaluating the potential uptake of these compounds by plants. Based on the results obtained in this study (column and batch sorption-desorption experiments), we suggest that PCs can be classified as slow-mobile compounds in SOM-rich soil layers. When these compounds pass this layer and/or are introduced into SOM-poor soils, their mobility increases significantly. Our data suggest that in semiarid soils (consisting of low SOM), PCs can potentially be transported to the groundwater in fields irrigated with reclaimed wastewater. Moreover, the higher mobility of the acid PCs (i.e., naproxen and diclofenac) in freshwater column systems suggests that their residues in soils irrigated with reclaimed wastewater can leach from the root zone and be transported to the groundwater after rain events. Our data obtained from the binding experiments of PCs with DOM demonstrate that the hydrophobic DOM fractions were more efficient at sorbing PCs than the more polar hydrophilic fractions at a pH near the pKa of the analytes. At the pH of natural semiarid water and soil systems, including that of reclaimed wastewater and biosolids, the role of the hydrophobic fractions as sorption domains is less important than the contribution of the hydrophilic fractions. We also hypothesize that the DOM fractions interact with each other at the molecular level and do not act as independent sorption domains. In summary, our data collected in the BARD project demonstrate that the sorption abilities of the DOM fractions can also significantly affect the mobility of pharmaceutical compounds in soils influenced by intensive irrigation with treated wastewater or amended with biosolids.
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Borch, Thomas, Yitzhak Hadar, and Tamara Polubesova. Environmental fate of antiepileptic drugs and their metabolites: Biodegradation, complexation, and photodegradation. United States Department of Agriculture, January 2012. http://dx.doi.org/10.32747/2012.7597927.bard.
Full textAbstract:
Many pharmaceutical compounds are active at very low doses, and a portion of them regularly enters municipal sewage systems and wastewater-treatment plants following use, where they often do not fully degrade. Two such compounds, CBZ and LTG, have been detected in wastewater effluents, surface waters, drinking water, and irrigation water, where they pose a risk to the environment and the food supply. These compounds are expected to interact with organic matter in the environment, but little is known about the effect of such interactions on their environmental fate and transport. The original objectives of our research, as defined in the approved proposal, were to: Determine the rates, mechanisms and products of photodegradation of LTG, CBZ and selected metabolites in waters exposed to near UV light, and the influence of DOM type and binding processes on photodegradation. Determine the potential and pathways for biodegradation of LTG, CBZ and selected metabolites using a white rot fungus (Pleurotusostreatus) and ADP, and reveal the effect of DOM complexation on these processes. Reveal the major mechanisms of binding of LTG, CBZ and selected metabolites to DOM and soil in the presence of DOM, and evaluate the effect of this binding on their photodegradation and/or biodegradation. We determined that LTG undergoes relatively slow photodegradation when exposed to UV light, and that pH affects each of LTG’s ability to absorb UV light, the efficiency of the resulting reaction, and the identities of LTG’sphotoproducts (t½ = 230 to 500 h during summer at latitude 40 °N). We observed that LTG’sphotodegradation is enhanced in the presence of DOM, and hypothesized that LTG undergoes direct reactions with DOM components through nucleophilic substitution reactions. In combination, these data suggest that LTG’s fate and transport in surface waters are controlled by environmental conditions that vary with time and location, potentially affecting the environment and irrigation waters. We determined that P. ostreatusgrows faster in a rich liquid medium (glucose peptone) than on a natural lignocellulosic substrate (cotton stalks) under SSF conditions, but that the overall CBZ removal rate was similar in both media. Different and more varied transformation products formed in the solid state culture, and we hypothesized that CBZ degradation would proceed further when P. ostreatusand the ᵉⁿᶻʸᵐᵃᵗⁱᶜ ᵖʳᵒᶠⁱˡᵉ ʷᵉʳᵉ ᵗᵘⁿᵉᵈ ᵗᵒ ˡⁱᵍⁿⁱⁿ ᵈᵉᵍʳᵃᵈᵃᵗⁱᵒⁿ. ᵂᵉ ᵒᵇˢᵉʳᵛᵉᵈ ¹⁴C⁻Cᴼ2 ʳᵉˡᵉᵃˢᵉ ʷʰᵉⁿ ¹⁴C⁻ᶜᵃʳᵇᵒⁿʸˡ⁻ labeled CBZ was used as the substrate in the solid state culture (17.4% of the initial radioactivity after 63 days of incubation), but could not conclude that mineralization had occurred. In comparison, we determined that LTG does not degrade in agricultural soils irrigated with treated wastewater, but that P. ostreatusremoves up to 70% of LTG in a glucose peptone medium. We detected various metabolites, including N-oxides and glycosides, but are still working to determine the degradation pathway. In combination, these data suggest that P. ostreatuscould be an innovative and effective tool for CBZ and LTG remediation in the environment and in wastewater used for irrigation. In batch experiments, we determined that the sorption of LTG, CBZ and selected metabolites to agricultural soils was governed mainly by SOM levels. In lysimeter experiments, we also observed LTG and CBZ accumulation in top soil layers enriched with organic matter. However, we detected CBZ and one of its metabolites in rain-fed wheat previously irrigated with treated wastewater, suggesting that their sorption was reversible, and indicating the potential for plant uptake and leaching. Finally, we used macroscale analyses (including adsorption/desorption trials and resin-based separations) with molecular- level characterization by FT-ICR MS to demonstrate the adsorptive fractionation of DOM from composted biosolids by mineral soil. This suggests that changes in soil and organic matter types will influence the extent of LTG and CBZ sorption to agricultural soils, as well as the potential for plant uptake and leaching.
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Banin, Amos, Joseph Stucki, and Joel Kostka. Redox Processes in Soils Irrigated with Reclaimed Sewage Effluents: Field Cycles and Basic Mechanism. United States Department of Agriculture, July 2004. http://dx.doi.org/10.32747/2004.7695870.bard.
Full textAbstract:
The overall objectives of the project were: (a) To measure and study in situ the effect of irrigation with reclaimed sewage effluents on redox processes and related chemical dynamics in soil profiles of agricultural fields. (b) To study under controlled conditions the kinetics and equilibrium states of selected processes that affect redox conditions in field soils or that are effected by them. Specifically, these include the effects on heavy metals sorption and desorption, and the effect on pesticide degradation. On the basis of the initial results from the field study, increased effort was devoted to clarifying and quantifying the effects of plants and water regime on the soil's redox potential while the study of heavy metals sorption was limited. The use of reclaimed sewage effluents as agricultural irrigation water is increasing at a significant rate. The relatively high levels of suspended and, especially, dissolved organic matter and nitrogen in effluents may affect the redox regime in field soils irrigated with them. In turn, the changes in redox regime may affect, among other parameters, the organic matter and nitrogen dynamics of the root zone and trace organic decomposition processes. Detailed data of the redox potential regime in field plots is lacking, and the detailed mechanisms of its control are obscure and not quantified. The study established the feasibility of long-term, non-disturbing monitoring of redox potential regime in field soils. This may enable to manage soil redox under conditions of continued inputs of wastewater. The importance of controlling the degree of wastewater treatment, particularly of adding ultrafiltration steps and/or tertiary treatment, may be assessed based on these and similar results. Low redox potential was measured in a field site (Site A, KibutzGivat Brenner), that has been irrigated with effluents for 30 years and was used for 15 years for continuous commercial sod production. A permanently reduced horizon (Time weighted averaged pe= 0.33±3.0) was found in this site at the 15 cm depth throughout the measurement period of 10 months. A drastic cultivation intervention, involving prolonged drying and deep plowing operations may be required to reclaim such soils. Site B, characterized by a loamy texture, irrigated with tap water for about 20 years was oxidized (Time weighted average pe=8.1±1.0) throughout the measurement period. Iron in the solid phases of the Givat Brenner soils is chemically-reduced by irrigation. Reduced Fe in these soils causes a change in reactivity toward the pesticide oxamyl, which has been determined to be both cytotoxic and genotoxic to mammalian cells. Reaction of oxamyl with reduced-Fe clay minerals dramatically decreases its cytotoxicity and genotoxicity to mammalian cells. Some other pesticides are affected in the same manner, whereas others are affected in the opposite direction (become more cyto- and genotoxic). Iron-reducing bacteria (FeRB) are abundant in the Givat Brenner soils. FeRB are capable of coupling the oxidation of small molecular weight carbon compounds (fermentation products) to the respiration of iron under anoxic conditions, such as those that occur under flooded soil conditions. FeRB from these soils utilize a variety of Fe forms, including Fe-containing clay minerals, as the sole electron acceptor. Daily cycles of the soil redox potential were discovered and documented in controlled-conditions lysimeter experiments. In the oxic range (pe=12-8) soil redox potential cycling is attributed to the effect of the daily temperature cycle on the equilibrium constant of the oxygenation reaction of H⁺ to form H₂O, and is observed under both effluent and freshwater irrigation. The presence of plants affects considerably the redox potential regime of soils. Redox potential cycling coupled to the irrigation cycles is observed when the soil becomes anoxic and the redox potential is controlled by the Fe(III)/Fe(II) redox couple. This is particularly seen when plants are grown. Re-oxidation of the soil after soil drying at the end of an irrigation cycle is affected to some degree by the water quality. Surprisingly, the results suggest that under certain conditions recovery is less pronounced in the freshwater irrigated soils.