For antibiotic-enriched waste activated sludge, classical iron-based chemical conditioning significantly enhanced sludge dewaterability. Nevertheless, the intricate constituents within sludge rapidly depleted reactive oxygen species (ROS), leading to challenges such as excessive production of iron sludge and inadequate elimination of antibiotics from sludge. Herein, we proposed an innovative strategy integrating biochar with Fe(II) for peroxymonosulfate (PMS) activation, aiming to enhance both sludge dewaterability and antibiotics elimination simultaneously. Compared to classical chemical conditioning of Fe(II)/PMS, the presence of biochar not only reduced bound water content of sludge from 1.36 g/g DS to 0.97 g/g DS, but also enhanced sulfamethoxazole (SMX) degradation rate constant from 0.015 min-1 to 0.042 min-1. Mechanism studies disclosed the essential roles of biochar in modulating Fe oxidative states distribution and reaction sites in multiphase. Initially, biochar elevated Fe(II)/Fe(III) ratio from 0.38 to 0.78 by abundant carbon defects, which significantly promoted the cumulative concentration of predominant ROS, hydroxyl radicals (•OH), from 4.6 mM to 8.1 mM. Subsequently, EPS underwent destruction by •OH, leading to the liberation of antibiotics and negatively charged polysaccharides (PS), proteins (PN). Secondly, biochar enriched hydrophobic PN with an elevated ratio of PN/PS from 0.92 to 1.50, while the charge neutralization occurred between Fe(II)/Fe(III) and PN, PS, leading to sludge particles granulation. Finally, the mesoporous structure of biochar not only achieved SMX enrichment, but also enhanced the mass transfer of Fe(II)/Fe(III) from sludge aqueous phase to its surface, ensuring that the in-situ generated •OH efficiently targets the locally concentrated SMX. Overall, this work provides a new guidance for developing biochar-mediated chemical conditioning, aiming to enhance the generation and utilization of •OH for antibiotics elimination from sludge.
{"title":"Enhanced Sludge Dewaterability and Confined Antibiotics Degradation in Biochar-Mediated Chemical Conditioning through Modulating Fe Oxidative States Distribution and Reaction sites in Multiphase","authors":"Siqi Wang, Fang Luo, Lingzhi He, Zhuo Liu, Jia Wang, Zhuwei Liao, Huijie Hou, Junwen Li, Xiaohan Ning, Zhuqi Chen","doi":"10.1016/j.watres.2024.122789","DOIUrl":"https://doi.org/10.1016/j.watres.2024.122789","url":null,"abstract":"For antibiotic-enriched waste activated sludge, classical iron-based chemical conditioning significantly enhanced sludge dewaterability. Nevertheless, the intricate constituents within sludge rapidly depleted reactive oxygen species (ROS), leading to challenges such as excessive production of iron sludge and inadequate elimination of antibiotics from sludge. Herein, we proposed an innovative strategy integrating biochar with Fe(II) for peroxymonosulfate (PMS) activation, aiming to enhance both sludge dewaterability and antibiotics elimination simultaneously. Compared to classical chemical conditioning of Fe(II)/PMS, the presence of biochar not only reduced bound water content of sludge from 1.36 g/g DS to 0.97 g/g DS, but also enhanced sulfamethoxazole (SMX) degradation rate constant from 0.015 min<sup>-1</sup> to 0.042 min<sup>-1</sup>. Mechanism studies disclosed the essential roles of biochar in modulating Fe oxidative states distribution and reaction sites in multiphase. Initially, biochar elevated Fe(II)/Fe(III) ratio from 0.38 to 0.78 by abundant carbon defects, which significantly promoted the cumulative concentration of predominant ROS, hydroxyl radicals (•OH), from 4.6 mM to 8.1 mM. Subsequently, EPS underwent destruction by •OH, leading to the liberation of antibiotics and negatively charged polysaccharides (PS), proteins (PN). Secondly, biochar enriched hydrophobic PN with an elevated ratio of PN/PS from 0.92 to 1.50, while the charge neutralization occurred between Fe(II)/Fe(III) and PN, PS, leading to sludge particles granulation. Finally, the mesoporous structure of biochar not only achieved SMX enrichment, but also enhanced the mass transfer of Fe(II)/Fe(III) from sludge aqueous phase to its surface, ensuring that the in-situ generated •OH efficiently targets the locally concentrated SMX. Overall, this work provides a new guidance for developing biochar-mediated chemical conditioning, aiming to enhance the generation and utilization of •OH for antibiotics elimination from sludge.","PeriodicalId":443,"journal":{"name":"Water Research","volume":"11 1","pages":""},"PeriodicalIF":12.8,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142610499","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}
Pub Date : 2024-11-13DOI: 10.1016/j.watres.2024.122760
Yan Lu , Tao Liu , Hui Wang , Lukun Zuo , Shihu Hu , Zhiguo Yuan , Wayne Bagg , Jianhua Guo
Dissolved methane is a hurdle for anaerobic wastewater treatment, which would be stripped into the atmosphere by conventional bubble aeration and increase the release of greenhouse gases into the environment. The high oxygen transfer efficiency and less turbulence in membrane aerated biofilm reactor (MABR) could prevent the stripping of dissolved methane. In this study, an MABR was established to remove dissolved methane aerobically in parallel to the nitrogen removal driven by the anammox process. The long-term results demonstrated that aerobic methane oxidation has a short start-up period, in which a high level (>90 %) of dissolved methane removal was achieved in 20 days. Meanwhile, the anammox-based nitrogen removal process reached a total nitrogen removal rate of ∼150 mg N/L/d (0.27 g N/m2/d). In situ batch tests confirmed the active bioreactions of ammonia-oxidizing bacteria, nitrite-oxidizing bacteria, anammox bacteria and aerobic methanotrophs, while 16S rRNA gene amplicon sequencing further validated their existence. Moreover, nitrite/nitrate-dependent anaerobic methane oxidation (n-DAMO) bacteria were enriched to a relative abundance of 2.5 % on Day 372, suggesting their potential role in removing nitrogen and dissolved methane in the MABR. This study provides an alternative technology for removing dissolved methane and nitrogen in parallel from anaerobically treated wastewater.
{"title":"Gas-delivery membrane as an alternative aeration method to remove dissolved methane from anaerobically treated wastewater","authors":"Yan Lu , Tao Liu , Hui Wang , Lukun Zuo , Shihu Hu , Zhiguo Yuan , Wayne Bagg , Jianhua Guo","doi":"10.1016/j.watres.2024.122760","DOIUrl":"10.1016/j.watres.2024.122760","url":null,"abstract":"<div><div>Dissolved methane is a hurdle for anaerobic wastewater treatment, which would be stripped into the atmosphere by conventional bubble aeration and increase the release of greenhouse gases into the environment. The high oxygen transfer efficiency and less turbulence in membrane aerated biofilm reactor (MABR) could prevent the stripping of dissolved methane. In this study, an MABR was established to remove dissolved methane aerobically in parallel to the nitrogen removal driven by the anammox process. The long-term results demonstrated that aerobic methane oxidation has a short start-up period, in which a high level (>90 %) of dissolved methane removal was achieved in 20 days. Meanwhile, the anammox-based nitrogen removal process reached a total nitrogen removal rate of ∼150 mg N/L/d (0.27 g N/m<sup>2</sup>/d). In situ batch tests confirmed the active bioreactions of ammonia-oxidizing bacteria, nitrite-oxidizing bacteria, anammox bacteria and aerobic methanotrophs, while 16S rRNA gene amplicon sequencing further validated their existence. Moreover, nitrite/nitrate-dependent anaerobic methane oxidation (n-DAMO) bacteria were enriched to a relative abundance of 2.5 % on Day 372, suggesting their potential role in removing nitrogen and dissolved methane in the MABR. This study provides an alternative technology for removing dissolved methane and nitrogen in parallel from anaerobically treated wastewater.</div></div>","PeriodicalId":443,"journal":{"name":"Water Research","volume":"268 ","pages":"Article 122760"},"PeriodicalIF":11.4,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142601583","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}
Pub Date : 2024-11-13DOI: 10.1016/j.watres.2024.122773
Feng Wang , Wenxuan Huang , Jiale Chen , Yuting Luo , Jiashun Cao , Fang Fang , Xuran Liu , Yang Wu , Jingyang Luo
Waste activated sludge (WAS) presents both resource recovery potential and pollution risks, making its efficient treatment challenging. Anaerobic digestion is broadly recognized as a green and sustainable approach to WAS treatment, whose efficiency is easily impacted by the exogeneous pollutants in WAS. However, the impact of polyhexamethylene guanidine (PHMG), as a widely-used non-antibiotic disinfectant, on WAS digestion under semi-continuous flow conditions remains unclear. In this study, CH4 production decreased from 16.1 mL/g volatile suspended solids (VSS) in the control to 13.2 mL/g VSS and 0.3 mL/g VSS under low and high PHMG exposure, respectively, while PHMG increased the number of antibiotic resistance gene (ARG) copies per bacterium by 4.6–12.7 %. Molecular docking analysis revealed that PHMG could spontaneously bind to and disintegrate WAS (binding energy:2.35 and -9.62 kcal/mol), increasing the likelihood of microbial exposure to PHMG. This led to an increase in bacterial abundance and a reduction in archaeal populations, resulting in bacterial dominance in ecological niches. The network topology index in PHMG-treated reactors was consistently lower than in the control, with a higher proportion of negatively correlated links, indicating a more antagonistic relationship between bacteria and archaea. Consequently, PHMG significantly interfered with key genes involved in CH4 biosynthesis (e.g., mch and mtd). Interestingly, methanogenic activity and archaeal chemotaxis (e.g., rfk and cheA) partially recovered under low PHMG exposure due to archaeal adaptation through quorum sensing and two-component systems. However, this adaptation process also contributed to the propagation of ARGs through horizontal gene transfer, facilitated by the enhancement of mobile genetic elements and ARGs hosts. These findings confirm the ecological risks of PHMG and highlight the need for effective WAS disposal strategies.
{"title":"Non-antibiotic disinfectant synchronously interferes methane production and antibiotic resistance genes propagation during sludge anaerobic digestion: Activation of microbial adaptation and reconfiguration of bacteria-archaea synergies","authors":"Feng Wang , Wenxuan Huang , Jiale Chen , Yuting Luo , Jiashun Cao , Fang Fang , Xuran Liu , Yang Wu , Jingyang Luo","doi":"10.1016/j.watres.2024.122773","DOIUrl":"10.1016/j.watres.2024.122773","url":null,"abstract":"<div><div>Waste activated sludge (WAS) presents both resource recovery potential and pollution risks, making its efficient treatment challenging. Anaerobic digestion is broadly recognized as a green and sustainable approach to WAS treatment, whose efficiency is easily impacted by the exogeneous pollutants in WAS. However, the impact of polyhexamethylene guanidine (PHMG), as a widely-used non-antibiotic disinfectant, on WAS digestion under semi-continuous flow conditions remains unclear. In this study, CH<sub>4</sub> production decreased from 16.1 mL/g volatile suspended solids (VSS) in the control to 13.2 mL/g VSS and 0.3 mL/g VSS under low and high PHMG exposure, respectively, while PHMG increased the number of antibiotic resistance gene (ARG) copies per bacterium by 4.6–12.7 %. Molecular docking analysis revealed that PHMG could spontaneously bind to and disintegrate WAS (binding energy:2.35 and -9.62 kcal/mol), increasing the likelihood of microbial exposure to PHMG. This led to an increase in bacterial abundance and a reduction in archaeal populations, resulting in bacterial dominance in ecological niches. The network topology index in PHMG-treated reactors was consistently lower than in the control, with a higher proportion of negatively correlated links, indicating a more antagonistic relationship between bacteria and archaea. Consequently, PHMG significantly interfered with key genes involved in CH<sub>4</sub> biosynthesis (<em>e.g., mch</em> and <em>mtd</em>). Interestingly, methanogenic activity and archaeal chemotaxis (<em>e.g., rfk</em> and <em>cheA</em>) partially recovered under low PHMG exposure due to archaeal adaptation through quorum sensing and two-component systems. However, this adaptation process also contributed to the propagation of ARGs through horizontal gene transfer, facilitated by the enhancement of mobile genetic elements and ARGs hosts. These findings confirm the ecological risks of PHMG and highlight the need for effective WAS disposal strategies.</div></div>","PeriodicalId":443,"journal":{"name":"Water Research","volume":"268 ","pages":"Article 122773"},"PeriodicalIF":11.4,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142601584","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}
Pub Date : 2024-11-13DOI: 10.1016/j.watres.2024.122772
Junwu Xiong, Chang Pu, Zhe Qian, Jiapei Yi, Kang Wang, Chi Zhang, Wei Liu, Wei Chen, Li Xu, Shihua Qi, Zulin Zhang, Hao Zhang, Kevin C. Jones
Neonicotinoid insecticides (NNIs) are among the most widely-used insecticides, although their threat to non-target organisms has attracted attention in recent years. In this study, a diffusive gradient in thin-films (DGT) passive sampling technique was developed for in situ monitoring of time-weighted average (TWA) concentrations of NNIs in groundwater and wastewater. Systematic studies demonstrated that DGT with HLB as binding gels (HLB-DGT) is suitable for quantitative sampling of NNIs under a wide range of conditions, independent of pH (5–9.5), ionic strength (0.001–0.5 M) and dissolved organic matter (0–10 mg/L). The HLB-DGT performance was also independent of the typical groundwater ionic environments. The thicknesses of in-situ measured diffusive boundary layer were 0.35 and 0.25 mm in the groundwater and effluent, respectively. HLB-DGT can provide TWA concentrations over 14–18 days’ deployment with linear uptake in both groundwater and wastewater. Concentrations and occurrence patterns of NNIs obtained by HLB-DGT were consistent with those measured from grab samples. The median TWA concentration of NNIs was 4.42 ng/L in water from the largest urban lake of China (the Tangxun Lake) in winter, with wastewater discharge being the main potential source. The reliability and stability of the HLB-DGT for measuring NNIs in the groundwater and surface water were confirmed and can be used to improve understanding of the occurrence and fate of NNIs in aquatic environment.
{"title":"Diffusive Gradients in Thin-films (DGT) for in situ Measurement of Neonicotinoid Insecticides (NNIs) in Waters","authors":"Junwu Xiong, Chang Pu, Zhe Qian, Jiapei Yi, Kang Wang, Chi Zhang, Wei Liu, Wei Chen, Li Xu, Shihua Qi, Zulin Zhang, Hao Zhang, Kevin C. Jones","doi":"10.1016/j.watres.2024.122772","DOIUrl":"https://doi.org/10.1016/j.watres.2024.122772","url":null,"abstract":"Neonicotinoid insecticides (NNIs) are among the most widely-used insecticides, although their threat to non-target organisms has attracted attention in recent years. In this study, a diffusive gradient in thin-films (DGT) passive sampling technique was developed for <em>in situ</em> monitoring of time-weighted average (TWA) concentrations of NNIs in groundwater and wastewater. Systematic studies demonstrated that DGT with HLB as binding gels (HLB-DGT) is suitable for quantitative sampling of NNIs under a wide range of conditions, independent of pH (5–9.5), ionic strength (0.001–0.5 M) and dissolved organic matter (0–10 mg/L). The HLB-DGT performance was also independent of the typical groundwater ionic environments. The thicknesses of <em>in-situ</em> measured diffusive boundary layer were 0.35 and 0.25 mm in the groundwater and effluent, respectively. HLB-DGT can provide TWA concentrations over 14–18 days’ deployment with linear uptake in both groundwater and wastewater. Concentrations and occurrence patterns of NNIs obtained by HLB-DGT were consistent with those measured from grab samples. The median TWA concentration of NNIs was 4.42 ng/L in water from the largest urban lake of China (the Tangxun Lake) in winter, with wastewater discharge being the main potential source. The reliability and stability of the HLB-DGT for measuring NNIs in the groundwater and surface water were confirmed and can be used to improve understanding of the occurrence and fate of NNIs in aquatic environment.","PeriodicalId":443,"journal":{"name":"Water Research","volume":"34 1","pages":""},"PeriodicalIF":12.8,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142601563","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}
Pub Date : 2024-11-13DOI: 10.1016/j.watres.2024.122787
Hai Xu, Wei Zou, Guangwei Zhu, Yu Qiu, Huiyun Li, Mengyuan Zhu, Hans W. Paerl, Zhixu Wu, Boqiang Qin, Yunlin Zhang
Impoundment reservoirs play a vital role as nutrient sinks, capable of retaining and exporting (N) and phosphorus (P) at different rates. The imbalance in P and N stoichiometry relative to phytoplankton demand often determines the limiting nutrient of algal growth for reservoirs. This critical factor has a substantial impact on the management of eutrophication, encompassing the formulation of nutrient control strategies and the setting of regulatory thresholds. Nonetheless, research remains relatively limited on algal limiting factors and nutrient stoichiometry interactions in subtropical impoundment reservoirs. This study fills a critical gap in the current research by providing a comprehensive assessment of the influences of N and P on phytoplankton biomass in Lake Qiandaohu, China. Utilizing field monitoring, nutrient addition experiments, and novel constraint line regression model, we provide new insights into the nutrient dynamics within the lake. Both bioassays experiment and statistics indicated predominant potentially P-limitation in Lake Qiandaohu owing to dam-induced deep-water conditions, characterized by a nearly 1:1 linear relationship between chlorophyll a (Chla) and total phosphorus concentrations. This underscores the pivotal role of P management in curbing algal blooms. Utilizing the constraint line equation that relates total P (TP) to Chla, we have proposed TP thresholds designed to keep Chla within the specified target ranges, specifically below 10, 12, 20, 24, 40, and 60 μg/L. Furthermore, leveraging Vollenweider's models with these TP concentration thresholds, the study has established TP loading targets that accommodate a range of hydrological conditions, from normal to wet and dry years. Furthermore, both nutrient addition experiment and constraint line regression model highlights potentially N and P co-limitation in specific regions, particularly the riverine zone, where the ratios of nitrogen to phosphorus are influenced by unsettled particulate matter resulting in relatively lower ratios. To address this, the study introduces TN thresholds and suggests localized control measures, including ecological floating macrophytes beds, as effective alternatives. Considering the uniform nutrient management policy currently applied across Chinese lakes and reservoirs, which may lead to under- or over-protection for individual water bodies, our research provides a cost-effective eutrophication management framework tailored for the subtropical Eastern Plains ecoregions.
{"title":"Impoundment-induced stoichiometric imbalance exacerbated phosphorus limitation in a deep subtropical reservoir: implications for eutrophication management","authors":"Hai Xu, Wei Zou, Guangwei Zhu, Yu Qiu, Huiyun Li, Mengyuan Zhu, Hans W. Paerl, Zhixu Wu, Boqiang Qin, Yunlin Zhang","doi":"10.1016/j.watres.2024.122787","DOIUrl":"https://doi.org/10.1016/j.watres.2024.122787","url":null,"abstract":"Impoundment reservoirs play a vital role as nutrient sinks, capable of retaining and exporting (N) and phosphorus (P) at different rates. The imbalance in P and N stoichiometry relative to phytoplankton demand often determines the limiting nutrient of algal growth for reservoirs. This critical factor has a substantial impact on the management of eutrophication, encompassing the formulation of nutrient control strategies and the setting of regulatory thresholds. Nonetheless, research remains relatively limited on algal limiting factors and nutrient stoichiometry interactions in subtropical impoundment reservoirs. This study fills a critical gap in the current research by providing a comprehensive assessment of the influences of N and P on phytoplankton biomass in Lake Qiandaohu, China. Utilizing field monitoring, nutrient addition experiments, and novel constraint line regression model, we provide new insights into the nutrient dynamics within the lake. Both bioassays experiment and statistics indicated predominant potentially P-limitation in Lake Qiandaohu owing to dam-induced deep-water conditions, characterized by a nearly 1:1 linear relationship between chlorophyll <em>a</em> (Chl<em>a</em>) and total phosphorus concentrations. This underscores the pivotal role of P management in curbing algal blooms. Utilizing the constraint line equation that relates total P (TP) to Chl<em>a</em>, we have proposed TP thresholds designed to keep Chl<em>a</em> within the specified target ranges, specifically below 10, 12, 20, 24, 40, and 60 μg/L. Furthermore, leveraging Vollenweider's models with these TP concentration thresholds, the study has established TP loading targets that accommodate a range of hydrological conditions, from normal to wet and dry years. Furthermore, both nutrient addition experiment and constraint line regression model highlights potentially N and P co-limitation in specific regions, particularly the riverine zone, where the ratios of nitrogen to phosphorus are influenced by unsettled particulate matter resulting in relatively lower ratios. To address this, the study introduces TN thresholds and suggests localized control measures, including ecological floating macrophytes beds, as effective alternatives. Considering the uniform nutrient management policy currently applied across Chinese lakes and reservoirs, which may lead to under- or over-protection for individual water bodies, our research provides a cost-effective eutrophication management framework tailored for the subtropical Eastern Plains ecoregions.","PeriodicalId":443,"journal":{"name":"Water Research","volume":"40 1","pages":""},"PeriodicalIF":12.8,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142601561","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}
Pub Date : 2024-11-12DOI: 10.1016/j.watres.2024.122785
Yangbo Qiu , Chao Wang , Ran Li , Lidong Feng , Shuaijun Yu , Jiangnan Shen , Long-Fei Ren , Jiahui Shao
Rapid development of semiconductor manufacturing and photovoltaic industry leads to significant generation of fluoride-rich and silica-rich wastewaters. Due to the emphasis on circular economy and resource recovery, there is a shift from regarding wastewater as waste to a recoverable resource. In this study, we present a uniquely designed dual-ion permeation Janus membrane (DPM)-assisted element reconstitution system (MERS) for selective recovery of high-value fluorosilicates from fluoride-rich and silica-rich wastewaters. The MERS with a configuration of cation-exchange membrane/bipolar membrane/DPM/anion-exchange membrane/cation-exchange membrane achieved HF formation in silica chamber and further SiF62- generation from the reaction of HF with SiO2. Driven by the electric field, SiF62- was then transported through DPM into acid chamber for fluorosilicates selective recovery. The DPM with positively-charged nanoporous substrate/negatively charged active layer enhanced electrostatic interaction for SiF62-/H+ transport and steric exclusion for coexisting foulants rejection. Ion transport mechanism analysis demonstrated DPM enhanced SiF62- migration while inhibiting back diffusion by electrostatic interaction and steric exclusion. Through the application of DPM, MERS showed rejections over 99 % for nanoparticles and over 90 % for organics. Thus, MERS stably selectively recovered SiF62- with recovery rate over 85 % and fluorosilicates purity over 99.5 %. Compared to traditional technologies, MERS achieved valuable resource recovery with the advantages of simple operation, small footprint and no secondary pollutant generation. Overall, this study provides a new strategy for simultaneous recovery of fluoride and silica from different waste streams, enabling a more sustainable strategy for semiconductor and photovoltaic industries development.
{"title":"Dual-ion permeation Janus membrane-assisted element reconstitution system enables fluorosilicate-oriented recovery from fluoride-rich and silica-rich wastewaters","authors":"Yangbo Qiu , Chao Wang , Ran Li , Lidong Feng , Shuaijun Yu , Jiangnan Shen , Long-Fei Ren , Jiahui Shao","doi":"10.1016/j.watres.2024.122785","DOIUrl":"10.1016/j.watres.2024.122785","url":null,"abstract":"<div><div>Rapid development of semiconductor manufacturing and photovoltaic industry leads to significant generation of fluoride-rich and silica-rich wastewaters. Due to the emphasis on circular economy and resource recovery, there is a shift from regarding wastewater as waste to a recoverable resource. In this study, we present a uniquely designed dual-ion permeation Janus membrane (DPM)-assisted element reconstitution system (MERS) for selective recovery of high-value fluorosilicates from fluoride-rich and silica-rich wastewaters. The MERS with a configuration of cation-exchange membrane/bipolar membrane/DPM/anion-exchange membrane/cation-exchange membrane achieved HF formation in silica chamber and further SiF<sub>6</sub><sup>2-</sup> generation from the reaction of HF with SiO<sub>2</sub>. Driven by the electric field, SiF<sub>6</sub><sup>2-</sup> was then transported through DPM into acid chamber for fluorosilicates selective recovery. The DPM with positively-charged nanoporous substrate/negatively charged active layer enhanced electrostatic interaction for SiF<sub>6</sub><sup>2-</sup>/H<sup>+</sup> transport and steric exclusion for coexisting foulants rejection. Ion transport mechanism analysis demonstrated DPM enhanced SiF<sub>6</sub><sup>2-</sup> migration while inhibiting back diffusion by electrostatic interaction and steric exclusion. Through the application of DPM, MERS showed rejections over 99 % for nanoparticles and over 90 % for organics. Thus, MERS stably selectively recovered SiF<sub>6</sub><sup>2-</sup> with recovery rate over 85 % and fluorosilicates purity over 99.5 %. Compared to traditional technologies, MERS achieved valuable resource recovery with the advantages of simple operation, small footprint and no secondary pollutant generation. Overall, this study provides a new strategy for simultaneous recovery of fluoride and silica from different waste streams, enabling a more sustainable strategy for semiconductor and photovoltaic industries development.</div></div>","PeriodicalId":443,"journal":{"name":"Water Research","volume":"268 ","pages":"Article 122785"},"PeriodicalIF":11.4,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142601581","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}
Pub Date : 2024-11-12DOI: 10.1016/j.watres.2024.122784
Jun Zuo, Siyu Yang, Hans-Peter Grossart, Peng Xiao, He Zhang, Rui Sun, Guoyou Li, Haoran Jiang, Qihang Zhao, Meng Jiao, Yao Cheng, Zeshuang Wang, Ruozhen Geng, Zengling Ma, Renhui Li
River ecosystems face escalating challenges due to altered flow regimes from human activities, such as urbanization with hydrological modifications. Understanding the role of microbial communities for ecosystems with changing flow regimes is still incomplete and remains at the frontier of aquatic microbial ecology. In particular, influences of riverine backward flow on the aquatic biota remain largely unknown. Therefore, we examined the impact of backward flow on the cyanobacterial, total prokaryotic, and eukaryotic communities in the Changdougang River, which naturally flows into Lake Taihu, through environmental DNA metabarcoding. We analyzed the differences in community diversity, assembly, and ecological network stability among groups under backward, weak, and forward flow direction conditions. Non-metric multidimensional scaling showed higher variations in communities of groups across flow direction conditions than seasonal groups. Variations in alpha and beta diversity showed that cyanobacterial and total prokaryotic communities experienced strong homogenization under backward flow conditions, whereas the ecological uniqueness of the eukaryotic community decreased. Assembly of the three flow-related communities was primarily governed by drift and dispersal limitation in stochastic processes. However, in the cyanobacterial community, homogeneous selection in deterministic processes increased from 22.79% to 42.86% under backward flow, aligning with trends observed in the checkerboard score (C-score). More importantly, the topological properties of ecological networks and the degree of average variation revealed higher stability in the cyanobacterial community compared to total prokaryotic and eukaryotic communities. Considering the variations in cohesion, the network stability in the cyanobacterial community decreased under backward flow. Our findings emphasize the distinct and sequentially diminishing responses of cyanobacterial, total prokaryotic, and eukaryotic communities to backward flowing rivers. This knowledge is crucial for maintaining ecological health of rivers, assessing the complex ecological impacts on hydrological engineering, and formulating sustainable water management strategies.
由于人类活动（如城市化和水文变化）导致水流机制发生变化，河流生态系统面临着日益严峻的挑战。人们对微生物群落在水流变化的生态系统中的作用的了解仍不全面，仍处于水生微生物生态学的前沿。特别是，河流倒流对水生生物群的影响在很大程度上仍然未知。因此，我们通过环境 DNA 代谢编码研究了逆流对自然流入太湖的长斗港河中蓝藻、原核生物和真核生物群落的影响。我们分析了后向、弱向和前向流向条件下群落多样性、集合度和生态网络稳定性的差异。非度量多维尺度显示，不同流向条件下群落的群落差异高于季节性群落。α和β多样性的变化表明，在逆流条件下，蓝藻群落和原核生物群落的同质性很强，而真核生物群落的生态独特性则有所下降。三种与水流有关的群落的形成主要受随机过程中的漂移和扩散限制的影响。然而，在蓝藻群落中，确定性过程中的同质性选择在逆流条件下从 22.79% 增加到 42.86%，这与棋盘格得分（C-score）中观察到的趋势一致。更重要的是，生态网络的拓扑特性和平均变异程度表明，蓝藻群落的稳定性高于原核生物和真核生物群落。考虑到内聚力的变化，蓝藻群落的网络稳定性在逆流条件下有所下降。我们的发现强调了蓝藻群落、原核生物群落和真核生物群落对逆流河流的不同反应和依次递减。这些知识对于维护河流生态健康、评估生态对水文工程的复杂影响以及制定可持续的水资源管理策略至关重要。
{"title":"Sequential decline in cyanobacterial, total prokaryotic, and eukaryotic responses to backward flow in a river connected to Lake Taihu","authors":"Jun Zuo, Siyu Yang, Hans-Peter Grossart, Peng Xiao, He Zhang, Rui Sun, Guoyou Li, Haoran Jiang, Qihang Zhao, Meng Jiao, Yao Cheng, Zeshuang Wang, Ruozhen Geng, Zengling Ma, Renhui Li","doi":"10.1016/j.watres.2024.122784","DOIUrl":"https://doi.org/10.1016/j.watres.2024.122784","url":null,"abstract":"River ecosystems face escalating challenges due to altered flow regimes from human activities, such as urbanization with hydrological modifications. Understanding the role of microbial communities for ecosystems with changing flow regimes is still incomplete and remains at the frontier of aquatic microbial ecology. In particular, influences of riverine backward flow on the aquatic biota remain largely unknown. Therefore, we examined the impact of backward flow on the cyanobacterial, total prokaryotic, and eukaryotic communities in the Changdougang River, which naturally flows into Lake Taihu, through environmental DNA metabarcoding. We analyzed the differences in community diversity, assembly, and ecological network stability among groups under backward, weak, and forward flow direction conditions. Non-metric multidimensional scaling showed higher variations in communities of groups across flow direction conditions than seasonal groups. Variations in alpha and beta diversity showed that cyanobacterial and total prokaryotic communities experienced strong homogenization under backward flow conditions, whereas the ecological uniqueness of the eukaryotic community decreased. Assembly of the three flow-related communities was primarily governed by drift and dispersal limitation in stochastic processes. However, in the cyanobacterial community, homogeneous selection in deterministic processes increased from 22.79% to 42.86% under backward flow, aligning with trends observed in the checkerboard score (C-score). More importantly, the topological properties of ecological networks and the degree of average variation revealed higher stability in the cyanobacterial community compared to total prokaryotic and eukaryotic communities. Considering the variations in cohesion, the network stability in the cyanobacterial community decreased under backward flow. Our findings emphasize the distinct and sequentially diminishing responses of cyanobacterial, total prokaryotic, and eukaryotic communities to backward flowing rivers. This knowledge is crucial for maintaining ecological health of rivers, assessing the complex ecological impacts on hydrological engineering, and formulating sustainable water management strategies.","PeriodicalId":443,"journal":{"name":"Water Research","volume":"72 1","pages":""},"PeriodicalIF":12.8,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142601582","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}
Pub Date : 2024-11-10DOI: 10.1016/j.watres.2024.122782
Dong Liu , Chenxue Zhang , Nuoxiao Yan , Yao Yan , Hongtao Duan
Lakes are vital sources of drinking water and essential habitats for humans and various other living organisms. However, many lakes face organic pollution due to anthropogenic disturbance and climatic influence, and the spatiotemporal changes of organic pollution in lakes over a large area are still unclear. Based on three monitoring datasets of chemical oxygen demand (COD) in 390 lakes, this study demonstrated the apparent spatiotemporal differences of organic pollution in lakes during the 1980s–2010s and the effects of water eutrophication and salinization. Throughout China, lake organic pollution showed a general spatial trend of being more severe in the north compared to the south. This pattern is reflected in the positive linear correlations between in-situ COD concentrations and lake latitude, observed in both the 1980s (p < 0.05) and the 2010s (p < 0.01). In terms of spatial differences, the influence of total nitrogen concentrations increased from 0.27% in the 1980s to 35.24% in the 2010s. Moreover, with increasing human activity, 78.31% of the studied lakes (N = 83) showed increasing COD concentrations during the 1980s–2010s. In addition, the logarithmic dissolved organic carbon concentrations were linearly correlated with log water conductivities (Pearson's r = 0.49, p < 0.01), suggesting that lake expansion would attenuate organic pollution in saline lakes through dilution effects. These results are valuable for understanding the spatiotemporal dynamics of organic pollution and are crucial for effective management of organic pollution in different lakes.
{"title":"Eutrophication exacerbated organic pollution in lakes across China during the 1980s–2010s","authors":"Dong Liu , Chenxue Zhang , Nuoxiao Yan , Yao Yan , Hongtao Duan","doi":"10.1016/j.watres.2024.122782","DOIUrl":"10.1016/j.watres.2024.122782","url":null,"abstract":"<div><div>Lakes are vital sources of drinking water and essential habitats for humans and various other living organisms. However, many lakes face organic pollution due to anthropogenic disturbance and climatic influence, and the spatiotemporal changes of organic pollution in lakes over a large area are still unclear. Based on three monitoring datasets of chemical oxygen demand (COD) in 390 lakes, this study demonstrated the apparent spatiotemporal differences of organic pollution in lakes during the 1980s–2010s and the effects of water eutrophication and salinization. Throughout China, lake organic pollution showed a general spatial trend of being more severe in the north compared to the south. This pattern is reflected in the positive linear correlations between <em>in-situ</em> COD concentrations and lake latitude, observed in both the 1980s (<em>p</em> < 0.05) and the 2010s (<em>p</em> < 0.01). In terms of spatial differences, the influence of total nitrogen concentrations increased from 0.27% in the 1980s to 35.24% in the 2010s. Moreover, with increasing human activity, 78.31% of the studied lakes (<em>N</em> = 83) showed increasing COD concentrations during the 1980s–2010s. In addition, the logarithmic dissolved organic carbon concentrations were linearly correlated with log water conductivities (Pearson's <em>r</em> = 0.49, <em>p</em> < 0.01), suggesting that lake expansion would attenuate organic pollution in saline lakes through dilution effects. These results are valuable for understanding the spatiotemporal dynamics of organic pollution and are crucial for effective management of organic pollution in different lakes.</div></div>","PeriodicalId":443,"journal":{"name":"Water Research","volume":"268 ","pages":"Article 122782"},"PeriodicalIF":11.4,"publicationDate":"2024-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142598182","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}
Pub Date : 2024-11-10DOI: 10.1016/j.watres.2024.122781
Sergěj Y.M.H. Seepma , Janou A. Koskamp , Michel G. Colin , Eleftheria Chiou , Rubayat Sobhan , Tim F.J. Bögels , Tom Bastiaan , Hadi Zamanian , Eric T. Baars , Peter J. de Moel , Mariëtte Wolthers , Onno J.I. Kramer
Drinking water softening has primarily prioritized public health, environmental benefits, social costs and enhanced client comfort. Annually, over 35 billion cubic meters of water is softened worldwide, often utilizing three main techniques: nanofiltration, ion exchange and seeded crystallization by pellet softening. However, recent modifications in pellet softening, including changes in seeding materials and acid conditioning used post-softening, have not fully achieved desired flexibility and optimization. This highlights the need of an integral approach, as drinking water softening is just one step in the drinking water treatment chain, which includes ozonation, softening, biological active carbon filtration (BACF) and sand filtration among others. In addition, pellet softening is often practiced based on operator knowledge, lacking practical key reactor performance indicators (KPIs) for efficient control. For that reason, we propose a newly and improved integral mechanistic model designed to accurately predict (1) calcite removal rates in drinking water through seeded crystallization in pellet softening reactors, (2) the saturation of the filter bed in the subsequent treatment step, (3) values for the KPIs steering the softening efficiency. Our new mechanistic model integrates insights from hydrodynamics, thermodynamics, mass transfer kinetics, nucleation and reactor engineering, focussing on critical variables such as temperature, linear velocity, pellet particle size and saturation index with respect to calcite. Our model was validated with data from the Waternet Weesperkarspel drinking water treatment plant in Amsterdam, The Netherlands, but implies universal applicability for addressing industrial challenges beyond drinking water softening. The implementation of our model proposes five effective KPIs to optimize the softening process, chemical usage, and reactor design. The advantage of this model is that it eliminates the application of numerical methods and fills a significant gap in the field by providing predictions of the carry-over (i.e., the produced CaCO3 fines leaving the fluidized bed) from water softening practices. With our model, the calcium removal rate is predicted with an average standard deviation (SD) of 40 % and the consequential clogging prediction of the BACF bed with an average SD of 130 %. Ultimately, our model provides crucial insights for operational management and decision-making in drinking water treatment plants, steering towards a more circular and environmentally sustainable process.
{"title":"Mechanistic model advancements for optimal calcium removal in water treatment: Integral operation improvements and reactor design strategies","authors":"Sergěj Y.M.H. Seepma , Janou A. Koskamp , Michel G. Colin , Eleftheria Chiou , Rubayat Sobhan , Tim F.J. Bögels , Tom Bastiaan , Hadi Zamanian , Eric T. Baars , Peter J. de Moel , Mariëtte Wolthers , Onno J.I. Kramer","doi":"10.1016/j.watres.2024.122781","DOIUrl":"10.1016/j.watres.2024.122781","url":null,"abstract":"<div><div>Drinking water softening has primarily prioritized public health, environmental benefits, social costs and enhanced client comfort. Annually, over 35 billion cubic meters of water is softened worldwide, often utilizing three main techniques: nanofiltration, ion exchange and seeded crystallization by pellet softening. However, recent modifications in pellet softening, including changes in seeding materials and acid conditioning used post-softening, have not fully achieved desired flexibility and optimization. This highlights the need of an integral approach, as drinking water softening is just one step in the drinking water treatment chain, which includes ozonation, softening, biological active carbon filtration (BACF) and sand filtration among others. In addition, pellet softening is often practiced based on operator knowledge, lacking practical key reactor performance indicators (KPIs) for efficient control. For that reason, we propose a newly and improved integral mechanistic model designed to accurately predict (1) calcite removal rates in drinking water through seeded crystallization in pellet softening reactors, (2) the saturation of the filter bed in the subsequent treatment step, (3) values for the KPIs steering the softening efficiency. Our new mechanistic model integrates insights from hydrodynamics, thermodynamics, mass transfer kinetics, nucleation and reactor engineering, focussing on critical variables such as temperature, linear velocity, pellet particle size and saturation index with respect to calcite. Our model was validated with data from the Waternet Weesperkarspel drinking water treatment plant in Amsterdam, The Netherlands, but implies universal applicability for addressing industrial challenges beyond drinking water softening. The implementation of our model proposes five effective KPIs to optimize the softening process, chemical usage, and reactor design. The advantage of this model is that it eliminates the application of numerical methods and fills a significant gap in the field by providing predictions of the carry-over (i.e., the produced CaCO<sub>3</sub> fines leaving the fluidized bed) from water softening practices. With our model, the calcium removal rate is predicted with an average standard deviation (SD) of 40 % and the consequential clogging prediction of the BACF bed with an average SD of 130 %. Ultimately, our model provides crucial insights for operational management and decision-making in drinking water treatment plants, steering towards a more circular and environmentally sustainable process.</div></div>","PeriodicalId":443,"journal":{"name":"Water Research","volume":"268 ","pages":"Article 122781"},"PeriodicalIF":11.4,"publicationDate":"2024-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142598183","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}
Pub Date : 2024-11-10DOI: 10.1016/j.watres.2024.122783
Hui Zhang, Junjie Yang, Zhiyu Sun, Yinkun Sun, Guanjin Liu, Dongwei Lu, Jun Ma
Peroxymonosulfate (PMS) can be used as a green oxidant to mitigate catalytic membranes fouling and restore filtration performance through advanced oxidation processes (AOP). However, the adjustment of oxidation pathways and the understanding of underlying mechanisms for efficient cleaning without sacrificing the filtration performance need to be studied systematically. We optimized the membranes microenvironment via thermal modification from 25 °C to 400 °C below the catalyst ZIF-8 framework's decomposition temperature. The modified membranes have a doubled pure water flux (158.3 LMH bar−1) and remain rejection rates due to intact ZIF-8 framework structure with “window-opening” effect. The methyl dissociation and self-catalyzed graphitization were regulated by changing temperature, resulting in adjustable nonradical pathway proportion (correlated with the C/Zn atomic ratio at 0.96). The enhanced nonradical pathway targeted attacks on electron-rich regions of organic compounds, resulting in efficient cleaning and almost complete flux recovery (99.3 %). The theoretical simulations revealed that methyl groups dissociation and graphitization significantly influence the electron density and adsorption energy at active sites for tunable oxidation pathways and enhanced catalytic performance. Our work offers a rational strategy to improve both filtration and catalytic performance in catalytic membranes. The enhanced understanding of oxidation mechanisms guides the design of designing efficient AOP membrane cleaning systems.
{"title":"Adjusting oxidation pathways via fine-tuning atomic ratios in window-opening MOF membranes for efficient self-cleaning","authors":"Hui Zhang, Junjie Yang, Zhiyu Sun, Yinkun Sun, Guanjin Liu, Dongwei Lu, Jun Ma","doi":"10.1016/j.watres.2024.122783","DOIUrl":"10.1016/j.watres.2024.122783","url":null,"abstract":"<div><div>Peroxymonosulfate (PMS) can be used as a green oxidant to mitigate catalytic membranes fouling and restore filtration performance through advanced oxidation processes (AOP). However, the adjustment of oxidation pathways and the understanding of underlying mechanisms for efficient cleaning without sacrificing the filtration performance need to be studied systematically. We optimized the membranes microenvironment via thermal modification from 25 °C to 400 °C below the catalyst ZIF-8 framework's decomposition temperature. The modified membranes have a doubled pure water flux (158.3 LMH bar<sup>−1</sup>) and remain rejection rates due to intact ZIF-8 framework structure with “window-opening” effect. The methyl dissociation and self-catalyzed graphitization were regulated by changing temperature, resulting in adjustable nonradical pathway proportion (correlated with the C/Zn atomic ratio at 0.96). The enhanced nonradical pathway targeted attacks on electron-rich regions of organic compounds, resulting in efficient cleaning and almost complete flux recovery (99.3 %). The theoretical simulations revealed that methyl groups dissociation and graphitization significantly influence the electron density and adsorption energy at active sites for tunable oxidation pathways and enhanced catalytic performance. Our work offers a rational strategy to improve both filtration and catalytic performance in catalytic membranes. The enhanced understanding of oxidation mechanisms guides the design of designing efficient AOP membrane cleaning systems.</div></div>","PeriodicalId":443,"journal":{"name":"Water Research","volume":"268 ","pages":"Article 122783"},"PeriodicalIF":11.4,"publicationDate":"2024-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142598181","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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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