Yujie Zang, Linlin Yan, Tieying Yang, Kai Wang, Yingjie Zhang, Enrico Drioli, Ma Jun, Yonggang Li, Shanshan Ji, Xiquan Cheng
Membrane separation technology has been recognized as an effective approach to remove dyes from dyeing wastewater that are crucial for improving the quality of pigmentation effect in the printing and dyeing industry. However, the trade-off relationship between membrane permeability and selectivity is an inherent pain point for molecular separation membrane, which hampers the development of large-scale applications of membrane separation process. In this work, we provide a facile approach to construct highly selective polyamide (PA) layer on ceramic membrane by interfacial polymerization of branched Polyethylenimine (PEI) and Trimesoyl Chloride (TMC) for selective separation towards dye/salt mixed wastewater. With high positive surface zeta-potential (100 mV) and excellent hydrophilicity, the PA/ceramic composite membranes exhibit ultra-high solution permeance (496.4 L·m-2·h-1·bar-1) when treating simulated dye/salt aqueous solutions containing 40 ppm Congo Red (CR) and 1 g L-1 NaCl, which is 30 times higher than that of commercial polyamide nanofiltration membranes. Interestingly, the separation factor of NaCl to CR of the PA/ceramic composite membranes reaches above 980, which is far superior to the state-of-art nanofiltration membranes reported recently. Moreover, PA/ceramic membranes possess a relatively ideal long-term stability, with their flux remaining at 280 L·m-2·h-1·bar-1 after 10 h of testing. Taken together, the PA/ceramic composite membranes show strong promise in dye desalination and purification.
{"title":"Constructing Polyamide/Ceramic Composite Membranes for Highly Efficient and Selective Separation towards Dye/salt Solution","authors":"Yujie Zang, Linlin Yan, Tieying Yang, Kai Wang, Yingjie Zhang, Enrico Drioli, Ma Jun, Yonggang Li, Shanshan Ji, Xiquan Cheng","doi":"10.1039/d4ew00135d","DOIUrl":"https://doi.org/10.1039/d4ew00135d","url":null,"abstract":"Membrane separation technology has been recognized as an effective approach to remove dyes from dyeing wastewater that are crucial for improving the quality of pigmentation effect in the printing and dyeing industry. However, the trade-off relationship between membrane permeability and selectivity is an inherent pain point for molecular separation membrane, which hampers the development of large-scale applications of membrane separation process. In this work, we provide a facile approach to construct highly selective polyamide (PA) layer on ceramic membrane by interfacial polymerization of branched Polyethylenimine (PEI) and Trimesoyl Chloride (TMC) for selective separation towards dye/salt mixed wastewater. With high positive surface zeta-potential (100 mV) and excellent hydrophilicity, the PA/ceramic composite membranes exhibit ultra-high solution permeance (496.4 L·m-2·h-1·bar-1) when treating simulated dye/salt aqueous solutions containing 40 ppm Congo Red (CR) and 1 g L-1 NaCl, which is 30 times higher than that of commercial polyamide nanofiltration membranes. Interestingly, the separation factor of NaCl to CR of the PA/ceramic composite membranes reaches above 980, which is far superior to the state-of-art nanofiltration membranes reported recently. Moreover, PA/ceramic membranes possess a relatively ideal long-term stability, with their flux remaining at 280 L·m-2·h-1·bar-1 after 10 h of testing. Taken together, the PA/ceramic composite membranes show strong promise in dye desalination and purification.","PeriodicalId":75,"journal":{"name":"Environmental Science: Water Research & Technology","volume":null,"pages":null},"PeriodicalIF":5.0,"publicationDate":"2024-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141258784","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Fernanda Bacaro, Eric Dickenson, Rebecca A. Trenholm and Daniel Gerrity
Correction for ‘N-Nitrosodimethylamine (NDMA) formation and mitigation in potable reuse treatment trains employing ozone and biofiltration’ by Fernanda Bacaro et al., Environ. Sci.: Water Res. Technol., 2019, 5, 713–725, https://doi.org/10.1039/C8EW00926K.
{"title":"Correction: N-Nitrosodimethylamine (NDMA) formation and mitigation in potable reuse treatment trains employing ozone and biofiltration","authors":"Fernanda Bacaro, Eric Dickenson, Rebecca A. Trenholm and Daniel Gerrity","doi":"10.1039/D4EW90024C","DOIUrl":"10.1039/D4EW90024C","url":null,"abstract":"<p >Correction for ‘<em>N</em>-Nitrosodimethylamine (NDMA) formation and mitigation in potable reuse treatment trains employing ozone and biofiltration’ by Fernanda Bacaro <em>et al.</em>, <em>Environ. Sci.: Water Res. Technol.</em>, 2019, <strong>5</strong>, 713–725, https://doi.org/10.1039/C8EW00926K.</p>","PeriodicalId":75,"journal":{"name":"Environmental Science: Water Research & Technology","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2024/ew/d4ew90024c?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141258813","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Winnie P Gerbens-Leenes, Santiago Vaca-Jiménez, Bunyod Holmatov, Davy Vanham
Although energy requires large amounts of water for its production, (inter)national statistics or reports on water demand for electricity for the African continent are scarce. Here we provide the spatially most detailed analysis presently available on freshwater demand for electricity for the recent year 2020, covering the whole of Africa. We conduct a major data mining effort using only freely accessible data. This results in 2,534 individual power plants, including 1,447 fossil (coal, oil and natural gas), 1,071 renewable (wind, sun, biomass, geothermal and hydropower with the distinction between reservoir and run-of-river or ROR hydropower) and 16 other (waste heat and nuclear) power plants. We categorized the power plants according to applied fuel, operation cycle, infrastructure, cooling system and local climate. The total water withdrawal (WW) and consumption (WC) amount to 33,108 and 23,822 million m3 per year (Mm3/year) respectively, for an annual electricity production of 1,050,674 GWh. Hydropower and natural gas, which have high water withdrawal intensities relative to other energy sources such as wind or sun, account for the largest fractions (70% respectively 27%) of total water withdrawal. Our database can be used at any spatial level, as we show results on the national, subnational and river basin level. Countries with high annual WW amounts include Egypt (8,937 Mm3), Ghana (7,893 Mm3), Zambia (5,262 Mm3), Mozambique (2,602 Mm3), Nigeria (2,309 Mm3) and South Africa (1,068 Mm3). River basins with high WW amounts include the Nile (10,377 Mm3), the Volta (7,765 Mm3), the Zambezi (7,596 Mm3) and the Niger (2,562 Mm3) river basins. In major river basins, these WW amounts do not exceed 10% of renewable water availability, except for the Volta basin, where the value is 43%. By providing all results in a fully open access database, we provide valuable statistics for any water management or energy stakeholder working in or on Africa.
{"title":"Spatially distributed freshwater demand for electricity in Africa","authors":"Winnie P Gerbens-Leenes, Santiago Vaca-Jiménez, Bunyod Holmatov, Davy Vanham","doi":"10.1039/d4ew00246f","DOIUrl":"https://doi.org/10.1039/d4ew00246f","url":null,"abstract":"Although energy requires large amounts of water for its production, (inter)national statistics or reports on water demand for electricity for the African continent are scarce. Here we provide the spatially most detailed analysis presently available on freshwater demand for electricity for the recent year 2020, covering the whole of Africa. We conduct a major data mining effort using only freely accessible data. This results in 2,534 individual power plants, including 1,447 fossil (coal, oil and natural gas), 1,071 renewable (wind, sun, biomass, geothermal and hydropower with the distinction between reservoir and run-of-river or ROR hydropower) and 16 other (waste heat and nuclear) power plants. We categorized the power plants according to applied fuel, operation cycle, infrastructure, cooling system and local climate. The total water withdrawal (WW) and consumption (WC) amount to 33,108 and 23,822 million m3 per year (Mm3/year) respectively, for an annual electricity production of 1,050,674 GWh. Hydropower and natural gas, which have high water withdrawal intensities relative to other energy sources such as wind or sun, account for the largest fractions (70% respectively 27%) of total water withdrawal. Our database can be used at any spatial level, as we show results on the national, subnational and river basin level. Countries with high annual WW amounts include Egypt (8,937 Mm3), Ghana (7,893 Mm3), Zambia (5,262 Mm3), Mozambique (2,602 Mm3), Nigeria (2,309 Mm3) and South Africa (1,068 Mm3). River basins with high WW amounts include the Nile (10,377 Mm3), the Volta (7,765 Mm3), the Zambezi (7,596 Mm3) and the Niger (2,562 Mm3) river basins. In major river basins, these WW amounts do not exceed 10% of renewable water availability, except for the Volta basin, where the value is 43%. By providing all results in a fully open access database, we provide valuable statistics for any water management or energy stakeholder working in or on Africa.","PeriodicalId":75,"journal":{"name":"Environmental Science: Water Research & Technology","volume":null,"pages":null},"PeriodicalIF":5.0,"publicationDate":"2024-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141189474","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tamara J. H. M. van Bergen, A. M. Schipper, D. Mooij, A. M. J. Ragas, M. W. Kuiper, A. J. Hendriks, M. A. J. Huijbregts, R. van Zelm
The removal of organic micropollutants (OMPs) in wastewater treatment plants (WWTPs) is critical to avoid pollution of the aquatic environment. While it is commonly assumed that removal rates are constant at low concentrations, this assumption remains untested across multiple WWTPs. The aim of this study was to test if removal rate constants of OMPs in activated sludge are indeed constant at low OMP concentrations. To that end, we related removal rate constants of 58 OMPs obtained from 14 WWTPs to influent OMP concentrations by applying linear mixed effect modelling in an all subsets modelling approach, also accounting for WWTP characteristics as well as physicochemical OMP properties. Influent OMP concentration and hydraulic retention time (HRT) were retained as predictors of removal rate constants in all best-supported models (within 2 AIC-units from the best model). The relationship between removal rate constant and concentration varied between OMPs. For most OMPs, the relationship was positive, except for valsartan and 2-hydroxyibuprofen, which may reflect toxic effects at higher concentrations. Our results indicate that the assumption of a constant removal rate at low concentrations is too simplistic and highlight the relevance of considering influent concentration in OMP fate predictions. This in turn may help in optimising OMP removal strategies, for example by concentrating wastewater in WWTPs.
{"title":"Removal rate constants are not necessarily constant: the case of organic micropollutant removal in wastewater treatment plants","authors":"Tamara J. H. M. van Bergen, A. M. Schipper, D. Mooij, A. M. J. Ragas, M. W. Kuiper, A. J. Hendriks, M. A. J. Huijbregts, R. van Zelm","doi":"10.1039/d4ew00377b","DOIUrl":"https://doi.org/10.1039/d4ew00377b","url":null,"abstract":"The removal of organic micropollutants (OMPs) in wastewater treatment plants (WWTPs) is critical to avoid pollution of the aquatic environment. While it is commonly assumed that removal rates are constant at low concentrations, this assumption remains untested across multiple WWTPs. The aim of this study was to test if removal rate constants of OMPs in activated sludge are indeed constant at low OMP concentrations. To that end, we related removal rate constants of 58 OMPs obtained from 14 WWTPs to influent OMP concentrations by applying linear mixed effect modelling in an all subsets modelling approach, also accounting for WWTP characteristics as well as physicochemical OMP properties. Influent OMP concentration and hydraulic retention time (HRT) were retained as predictors of removal rate constants in all best-supported models (within 2 AIC-units from the best model). The relationship between removal rate constant and concentration varied between OMPs. For most OMPs, the relationship was positive, except for valsartan and 2-hydroxyibuprofen, which may reflect toxic effects at higher concentrations. Our results indicate that the assumption of a constant removal rate at low concentrations is too simplistic and highlight the relevance of considering influent concentration in OMP fate predictions. This in turn may help in optimising OMP removal strategies, for example by concentrating wastewater in WWTPs.","PeriodicalId":75,"journal":{"name":"Environmental Science: Water Research & Technology","volume":null,"pages":null},"PeriodicalIF":5.0,"publicationDate":"2024-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141189473","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Byung-Kwang Yoo, Rei Goto, Masaaki Kitajima, Tomoko Sasaki, Sebastian Himmler
COVID-19 motivated the US and the European Union to establish a regular pathogen surveillance system at wastewater treatment plants, but other countries, including Japan, have been reluctant to adopt such a system. To determine whether a continuous pathogen surveillance system at wastewater treatment plants is economically justifiable in Japan, we conducted a contingent valuation experiment to estimate a hypothetical willingness to pay (WTP) for such a surveillance system. To collect primary data, an online WTP experiment was administered to a nationally representative sample in Japan in spring 2023 (N = 2,457). Results indicated that mean WTP was US $23.47 (Median $8.83) per household per year, and that around 97% of individuals had a non-zero WTP. The monetary valuation aggregated to the national level ($497 million based on the median value) exceeds the likely costs of maintaining the system in Japan ($33 million). Based on the population’s valuation of the nationwide wastewater surveillance system, its establishment would be economically justifiable in Japan. Our results are expected to inform stakeholders in Japan, the US, the European Union, and other countries considering expanding or maintaining wastewater surveillance systems that are applicable for diverse infectious diseases including COVID-19. For a future epidemic with uncertain risks, the surveillance systems’ economic efficiency (e.g., cost-effectiveness and return-on-investment) is difficult to assess. Eliciting taxpayers’ WTP can be informative for that purpose.
{"title":"Willingness to pay for nationwide wastewater surveillance system for infectious diseases in Japan","authors":"Byung-Kwang Yoo, Rei Goto, Masaaki Kitajima, Tomoko Sasaki, Sebastian Himmler","doi":"10.1039/d4ew00332b","DOIUrl":"https://doi.org/10.1039/d4ew00332b","url":null,"abstract":"COVID-19 motivated the US and the European Union to establish a regular pathogen surveillance system at wastewater treatment plants, but other countries, including Japan, have been reluctant to adopt such a system. To determine whether a continuous pathogen surveillance system at wastewater treatment plants is economically justifiable in Japan, we conducted a contingent valuation experiment to estimate a hypothetical willingness to pay (WTP) for such a surveillance system. To collect primary data, an online WTP experiment was administered to a nationally representative sample in Japan in spring 2023 (N = 2,457). Results indicated that mean WTP was US $23.47 (Median $8.83) per household per year, and that around 97% of individuals had a non-zero WTP. The monetary valuation aggregated to the national level ($497 million based on the median value) exceeds the likely costs of maintaining the system in Japan ($33 million). Based on the population’s valuation of the nationwide wastewater surveillance system, its establishment would be economically justifiable in Japan. Our results are expected to inform stakeholders in Japan, the US, the European Union, and other countries considering expanding or maintaining wastewater surveillance systems that are applicable for diverse infectious diseases including COVID-19. For a future epidemic with uncertain risks, the surveillance systems’ economic efficiency (e.g., cost-effectiveness and return-on-investment) is difficult to assess. Eliciting taxpayers’ WTP can be informative for that purpose.","PeriodicalId":75,"journal":{"name":"Environmental Science: Water Research & Technology","volume":null,"pages":null},"PeriodicalIF":5.0,"publicationDate":"2024-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141189529","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The rapid development of industrialization led to a significant rise in the discharge of dyes volume into the environment which are toxic and harmful for ecosystem. Green modification is considered the most effective and environmentally beneficial approach for producing eco-friendly materials due to its non-adverse effects on the biosphere. In this regard, we synthesized sustainable and cost-effective carbon nano-onions (CNOs) and examined their utility in adsorbing MO dye. CNOs demonstrated photocatalytic degradation of MO dye within 30 minutes at room temperature with outstanding efficiency of 99.99%. The kinetic regression and isotherm results confirmed that MO dye adsorption follows the pseudo-second order kinetics and Langmuir isotherm models. Furthermore, CNOs exhibited effective removal efficiency for MO dye in real water samples, similar to their performance in deionized water, with rates of 99.20%, 98.88%, and 97.22% for tap water, lake water, and dam water, respectively. The hydrophobic nature of CNOs renders them highly suitable for recyclable applications in the removal of MO dye from wastewater, exhibiting effectiveness for up to seven cycles. Significantly, treated wastewater has been examined for the barley plants growth. As a result, maximum growth of barley plants was found in treated wastewater, while in MO dye polluted water showed the retarded growth. The above results highlighted the virtuous development prospect of biomass-derived CNOs in wastewater remediation and further the practical uses of treated water.
工业化的快速发展导致排放到环境中的染料量大幅增加，这些染料对生态系统有毒有害。绿色改性因其对生物圈无不良影响，被认为是生产生态友好材料的最有效、最环保的方法。为此，我们合成了可持续且经济高效的碳纳米离子（CNOs），并研究了它们在吸附 MO 染料方面的效用。CNO 在室温下 30 分钟内对 MO 染料进行了光催化降解，降解效率高达 99.99%。动力学回归和等温线结果证实，MO 染料的吸附遵循伪二阶动力学和 Langmuir 等温线模型。此外，CNOs 在实际水样中对 MO 染料的有效去除率与其在去离子水中的表现相似，在自来水、湖水和大坝水中的去除率分别为 99.20%、98.88% 和 97.22%。CNOs 的疏水性使其非常适合用于去除废水中的 MO 染料，可循环使用长达七个周期。值得注意的是，经过处理的废水对大麦植物的生长进行了检测。结果发现，在经过处理的废水中，大麦植株的生长速度最快，而在受到 MO 染料污染的水中，大麦植株的生长速度较慢。上述结果凸显了生物质衍生 CNOs 在废水修复中的良性发展前景，并进一步推动了处理水的实际用途。
{"title":"Ecologically Viable Carbon Nano Onions for the Efficient Removal of Methyl Orange Azo Dye and its Environmental Assessment","authors":"Poonam Kumari, Kumud Malika Tripathi, Kamlendra Awasthi, Ragini Gupta","doi":"10.1039/d4ew00014e","DOIUrl":"https://doi.org/10.1039/d4ew00014e","url":null,"abstract":"The rapid development of industrialization led to a significant rise in the discharge of dyes volume into the environment which are toxic and harmful for ecosystem. Green modification is considered the most effective and environmentally beneficial approach for producing eco-friendly materials due to its non-adverse effects on the biosphere. In this regard, we synthesized sustainable and cost-effective carbon nano-onions (CNOs) and examined their utility in adsorbing MO dye. CNOs demonstrated photocatalytic degradation of MO dye within 30 minutes at room temperature with outstanding efficiency of 99.99%. The kinetic regression and isotherm results confirmed that MO dye adsorption follows the pseudo-second order kinetics and Langmuir isotherm models. Furthermore, CNOs exhibited effective removal efficiency for MO dye in real water samples, similar to their performance in deionized water, with rates of 99.20%, 98.88%, and 97.22% for tap water, lake water, and dam water, respectively. The hydrophobic nature of CNOs renders them highly suitable for recyclable applications in the removal of MO dye from wastewater, exhibiting effectiveness for up to seven cycles. Significantly, treated wastewater has been examined for the barley plants growth. As a result, maximum growth of barley plants was found in treated wastewater, while in MO dye polluted water showed the retarded growth. The above results highlighted the virtuous development prospect of biomass-derived CNOs in wastewater remediation and further the practical uses of treated water.","PeriodicalId":75,"journal":{"name":"Environmental Science: Water Research & Technology","volume":null,"pages":null},"PeriodicalIF":5.0,"publicationDate":"2024-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141170708","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yiwen Luo, Qing Zheng, Zhiyong Luo, Shuqing Xiang, Mei Dai
3,4-dichlorophenol (3,4-DCP) has been detected in industrial and domestic effluents, posing adverse effects on human health. Herein, ferrate (Fe(VI)) oxidation of 3,4-DCP was systemically and comprehensively investigated by determining its kinetics, mechanisms, and effect of anions. pH dependence of reaction kinetics was strong and the second-order reaction rate constant k varied nonlinearly from (342.82 ± 21.81) M-1s-1 to (8.21 ± 0.27) M-1s-1 with an increase in pH from 6.5 to 10.5, whereas its temperature dependence was quite weak. The individual species-specific second-order rate constants for the reaction were obtained using least-squares regression approach. Protonated Fe(VI) has higher reactivity than its unprotonated specie while 3,4-DCP is just the opposite, leading to the reaction of HFeO4- with 3,4-DCP- occurring fastest among four parallel reactions. Significantly, 3,4-DCP removal kinetics was inhibited by coexisting anions. Meanwhile, efficiency of 3,4-DCP removal by Fe(VI) at different Fe(VI) concentrations, solution pH, and coexisting anions was determined. Furthermore, eight intermediates of 3,4-DCP oxidation were identified, and a detailed mechanism involving hydroxylation, substitution, dechlorination, and ring-opening steps of Fe(VI)/3,4-DCP reaction was proposed. Removal of 3,4-DCP was enhanced in authentic waters, demonstrating that Fe(VI) could be regarded as an efficient technology for removing 3,4-DCP from water.
{"title":"Removal of 3,4-dichlorophenol from water utilizing ferrate(VI): Kinetic and mechanistic investigations, and effect of coexisting anions","authors":"Yiwen Luo, Qing Zheng, Zhiyong Luo, Shuqing Xiang, Mei Dai","doi":"10.1039/d4ew00274a","DOIUrl":"https://doi.org/10.1039/d4ew00274a","url":null,"abstract":"3,4-dichlorophenol (3,4-DCP) has been detected in industrial and domestic effluents, posing adverse effects on human health. Herein, ferrate (Fe(VI)) oxidation of 3,4-DCP was systemically and comprehensively investigated by determining its kinetics, mechanisms, and effect of anions. pH dependence of reaction kinetics was strong and the second-order reaction rate constant k varied nonlinearly from (342.82 ± 21.81) M-1s-1 to (8.21 ± 0.27) M-1s-1 with an increase in pH from 6.5 to 10.5, whereas its temperature dependence was quite weak. The individual species-specific second-order rate constants for the reaction were obtained using least-squares regression approach. Protonated Fe(VI) has higher reactivity than its unprotonated specie while 3,4-DCP is just the opposite, leading to the reaction of HFeO4- with 3,4-DCP- occurring fastest among four parallel reactions. Significantly, 3,4-DCP removal kinetics was inhibited by coexisting anions. Meanwhile, efficiency of 3,4-DCP removal by Fe(VI) at different Fe(VI) concentrations, solution pH, and coexisting anions was determined. Furthermore, eight intermediates of 3,4-DCP oxidation were identified, and a detailed mechanism involving hydroxylation, substitution, dechlorination, and ring-opening steps of Fe(VI)/3,4-DCP reaction was proposed. Removal of 3,4-DCP was enhanced in authentic waters, demonstrating that Fe(VI) could be regarded as an efficient technology for removing 3,4-DCP from water.","PeriodicalId":75,"journal":{"name":"Environmental Science: Water Research & Technology","volume":null,"pages":null},"PeriodicalIF":5.0,"publicationDate":"2024-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141167532","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In the advanced oxidation system, the promoting effect of bicarbonate is relatively overlooked. Bicarbonate, as an inorganic anion widely present in natural waters, is extremely important for water treatment. Therefore, bicarbonate was added to the PDS/Cu2+ system to investigate the degradation mechanisms of organic contaminants. The generation of alkyl radicals in PDS/Cu2+/〖"HCO" 〗_"3" ^"-" system was first demonstrated through Electron Paramagnetic Resonance (EPR) testing. This study reveals that the introduced bicarbonate ions undergo transformation into alkyl radicals. The presence of alkyl radicals promotes the cycling of monovalent, divalent, and trivalent copper ions, facilitating the degradation of contaminants. The production of monovalent and trivalent copper ions in the reaction system was confirmed through UV-vis absorption spectroscopy and quenching experiments. Furthermore, the change in the oxidation state of copper ions was further confirmed through EPR testing. These findings not only shed new light on the degradation mechanism of the PDS/Cu2+ system in the presence of bicarbonate but also open up new avenues for the further application of bicarbonate in advanced oxidation processes.
{"title":"Strongly Enhanced persulfate activation by bicarbonate accelerated Cu (III)/Cu (I) redox cycle","authors":"Jun Zhang, Shenjun Wang, Yuhao Wu, Jiahai Ma","doi":"10.1039/d4ew00172a","DOIUrl":"https://doi.org/10.1039/d4ew00172a","url":null,"abstract":"In the advanced oxidation system, the promoting effect of bicarbonate is relatively overlooked. Bicarbonate, as an inorganic anion widely present in natural waters, is extremely important for water treatment. Therefore, bicarbonate was added to the PDS/Cu2+ system to investigate the degradation mechanisms of organic contaminants. The generation of alkyl radicals in PDS/Cu2+/〖\"HCO\" 〗_\"3\" ^\"-\" system was first demonstrated through Electron Paramagnetic Resonance (EPR) testing. This study reveals that the introduced bicarbonate ions undergo transformation into alkyl radicals. The presence of alkyl radicals promotes the cycling of monovalent, divalent, and trivalent copper ions, facilitating the degradation of contaminants. The production of monovalent and trivalent copper ions in the reaction system was confirmed through UV-vis absorption spectroscopy and quenching experiments. Furthermore, the change in the oxidation state of copper ions was further confirmed through EPR testing. These findings not only shed new light on the degradation mechanism of the PDS/Cu2+ system in the presence of bicarbonate but also open up new avenues for the further application of bicarbonate in advanced oxidation processes.","PeriodicalId":75,"journal":{"name":"Environmental Science: Water Research & Technology","volume":null,"pages":null},"PeriodicalIF":5.0,"publicationDate":"2024-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141167635","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Allyson Leigh Junker, Frederick Munk S Christensen, Lu Bai, Mads Koustrup Jørgensen, Peter Fojan, Alaa Khalil, Zongsu Wei
Amidst the discovery of widespread per- and polyfluoroalkyl substances (PFAS) contamination and growing concerns of prolonged exposure even at low levels, many water treatment facilities are adopting reversed osmosis and nanofiltration processes to address these pollutants. Yet, these technologies are not sustainable, generating highly concentrated brines and requiring high operational pressures and energy inputs. Meanwhile, ultrafiltration (UF) membranes operate at less than 1 bar of transmembrane pressure (TMP) but are considered ineffective at removing organic pollutants. However, surface modifications make it possible to remove PFAS via UF. This study investigated the use of an adsorptive, photocatalytic, iron-enhanced titanium nanotube activated carbon composite coating on UF membranes to simultaneously remove and degrade PFAS in situ. In a photo-membrane reactor (PMR) under UV irradiation, the membranes removed up to 80% of the initial PFOA within 2-hour and the average removal over two 8-hour operation cycles was 69%. Although PFOA removal decreased to 35% when tested on a mixed PFAS solution, 46% of PFOS was still removed and 95% of the adsorbed PFOA was destroyed, while short-chain PFAS were removed to a lesser degree. This work provides a proof-of-concept of the PMR technology, which with further development could provide a single-step treatment for aqueous PFAS contamination in groundwater and pretreated surface and waste waters.
{"title":"Emerging investigator series: Photocatalytic Treatment of PFAS in a Single-step Ultrafiltration Membrane Reactor","authors":"Allyson Leigh Junker, Frederick Munk S Christensen, Lu Bai, Mads Koustrup Jørgensen, Peter Fojan, Alaa Khalil, Zongsu Wei","doi":"10.1039/d4ew00224e","DOIUrl":"https://doi.org/10.1039/d4ew00224e","url":null,"abstract":"Amidst the discovery of widespread per- and polyfluoroalkyl substances (PFAS) contamination and growing concerns of prolonged exposure even at low levels, many water treatment facilities are adopting reversed osmosis and nanofiltration processes to address these pollutants. Yet, these technologies are not sustainable, generating highly concentrated brines and requiring high operational pressures and energy inputs. Meanwhile, ultrafiltration (UF) membranes operate at less than 1 bar of transmembrane pressure (TMP) but are considered ineffective at removing organic pollutants. However, surface modifications make it possible to remove PFAS via UF. This study investigated the use of an adsorptive, photocatalytic, iron-enhanced titanium nanotube activated carbon composite coating on UF membranes to simultaneously remove and degrade PFAS in situ. In a photo-membrane reactor (PMR) under UV irradiation, the membranes removed up to 80% of the initial PFOA within 2-hour and the average removal over two 8-hour operation cycles was 69%. Although PFOA removal decreased to 35% when tested on a mixed PFAS solution, 46% of PFOS was still removed and 95% of the adsorbed PFOA was destroyed, while short-chain PFAS were removed to a lesser degree. This work provides a proof-of-concept of the PMR technology, which with further development could provide a single-step treatment for aqueous PFAS contamination in groundwater and pretreated surface and waste waters.","PeriodicalId":75,"journal":{"name":"Environmental Science: Water Research & Technology","volume":null,"pages":null},"PeriodicalIF":5.0,"publicationDate":"2024-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141153782","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This work aims toward the remediation of multiple organic micropollutants simultaneously present in municipal wastewater. Catalytic pulsed plasma treatment (CPPT) coupled with TiO2 and N-TiO2 photocatalysts was employed to degrade naproxen (NPX), triclosan (TCS), and reactive red 180 (RR180). This study addressed a key challenge towards achieving Sustainable Development Goal (SDG) 6 for clean water and sanitation. The operating conditions were 23 kV at a pulse frequency of 33 Hz for a 50 mL sample volume. The synergy of photocatalysts with plasma was observed with N-TiO2 reducing the treatment time for complete degradation by 50% as compared to the non-catalytic system. This improvement was due to enhanced radical generation, catalyst activation by UV-visible light, and increased surface area. The enhancement in radical generation noted was ~85% for H2O2 and ~100% for •OH. The role of •SO4- in RR180 degradation was noted. The disc diffusion test showed no inhibition zone for NPX and TCS at 1 mg/L and RR180 at 10 mg/L within 8 min. The degradation yield increased by 25% compared to the non-catalytic system. Mineralization efficiency follows the order TCS > RR180 > NPX. Finally, CPPT demonstrates >99% degradation efficiency in the multipollutant system of real secondary treated wastewater, showcasing its broad applicability in diverse wastewater scenarios
{"title":"Catalytic Pulse Plasma Treatment for Organic Micro pollutants: Unveiling the Synergistic Role of Photocatalysts in Radical Generation and Degradation Mechanisms","authors":"Ritik Anand, Ligy Philip","doi":"10.1039/d4ew00167b","DOIUrl":"https://doi.org/10.1039/d4ew00167b","url":null,"abstract":"This work aims toward the remediation of multiple organic micropollutants simultaneously present in municipal wastewater. Catalytic pulsed plasma treatment (CPPT) coupled with TiO2 and N-TiO2 photocatalysts was employed to degrade naproxen (NPX), triclosan (TCS), and reactive red 180 (RR180). This study addressed a key challenge towards achieving Sustainable Development Goal (SDG) 6 for clean water and sanitation. The operating conditions were 23 kV at a pulse frequency of 33 Hz for a 50 mL sample volume. The synergy of photocatalysts with plasma was observed with N-TiO2 reducing the treatment time for complete degradation by 50% as compared to the non-catalytic system. This improvement was due to enhanced radical generation, catalyst activation by UV-visible light, and increased surface area. The enhancement in radical generation noted was ~85% for H2O2 and ~100% for •OH. The role of •SO4- in RR180 degradation was noted. The disc diffusion test showed no inhibition zone for NPX and TCS at 1 mg/L and RR180 at 10 mg/L within 8 min. The degradation yield increased by 25% compared to the non-catalytic system. Mineralization efficiency follows the order TCS > RR180 > NPX. Finally, CPPT demonstrates >99% degradation efficiency in the multipollutant system of real secondary treated wastewater, showcasing its broad applicability in diverse wastewater scenarios","PeriodicalId":75,"journal":{"name":"Environmental Science: Water Research & Technology","volume":null,"pages":null},"PeriodicalIF":5.0,"publicationDate":"2024-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141151598","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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