Water Research最新文献_第8页

Biological methane removal by groundwater trickling biofiltration for emissions reduction

IF 11.4 1区环境科学与生态学 Q1 ENGINEERING, ENVIRONMENTAL

Water Research

Pub Date : 2025-03-06 DOI: 10.1016/j.watres.2025.123450

Francesc Corbera-Rubio , Alje S. Boersma , Weren de Vet , Martin Pabst , Paul W.J.J. van der Wielen , Maartje A.H.J. van Kessel , Mark C.M. van Loosdrecht , Doris van Halem , Sebastian Lücker , Michele Laureni

Methane removal is an essential step in drinking water production from methane-rich groundwaters. Conventional aeration-based stripping results in significant direct methane emissions, contributing up to one-third of a treatment plant's total carbon footprint. To address this, a full-scale trickling filter was operated for biological methane oxidation upstream of a submerged sand filter, and its performance was compared to a conventional aeration–submerged sand filtration set-up. Full-scale data were combined with ex-situ batch assays and metagenome-resolved metaproteomics to quantify the individual contribution of the main (a)biotic processes and characterize the enriched microbial communities. Both treatment setups fully removed methane, iron, ammonium, and manganese, yet the underlying mechanisms differed significantly. Methane was completely removed from the effluent after trickling filtration, with stripping and biological oxidation each accounting for half of the removal, thereby halving overall methane emissions. Methane-oxidizing bacteria not only outcompeted nitrifiers in the trickling filter, but also likely contributed directly to ammonia oxidation. In contrast to the submerged filter preceded by methane stripping, signatures of biological iron oxidation were almost completely absent in the trickling filter, suggesting that the presence of methane directly or indirectly promotes chemical iron oxidation. All systems had similar ex-situ manganese oxidation capacities, yet removal occurred only in the submerged filters but not the trickling filter. Ultimately, our results demonstrate that trickling filtration is effective in promoting biological methane oxidation at comparable produced drinking water quality, highlighting its potential for advancing sustainable drinking water production.

{"title":"Biological methane removal by groundwater trickling biofiltration for emissions reduction","authors":"Francesc Corbera-Rubio , Alje S. Boersma , Weren de Vet , Martin Pabst , Paul W.J.J. van der Wielen , Maartje A.H.J. van Kessel , Mark C.M. van Loosdrecht , Doris van Halem , Sebastian Lücker , Michele Laureni","doi":"10.1016/j.watres.2025.123450","DOIUrl":"10.1016/j.watres.2025.123450","url":null,"abstract":"<div><div>Methane removal is an essential step in drinking water production from methane-rich groundwaters. Conventional aeration-based stripping results in significant direct methane emissions, contributing up to one-third of a treatment plant's total carbon footprint. To address this, a full-scale trickling filter was operated for biological methane oxidation upstream of a submerged sand filter, and its performance was compared to a conventional aeration–submerged sand filtration set-up. Full-scale data were combined with <em>ex-situ</em> batch assays and metagenome-resolved metaproteomics to quantify the individual contribution of the main (a)biotic processes and characterize the enriched microbial communities. Both treatment setups fully removed methane, iron, ammonium, and manganese, yet the underlying mechanisms differed significantly. Methane was completely removed from the effluent after trickling filtration, with stripping and biological oxidation each accounting for half of the removal, thereby halving overall methane emissions. Methane-oxidizing bacteria not only outcompeted nitrifiers in the trickling filter, but also likely contributed directly to ammonia oxidation. In contrast to the submerged filter preceded by methane stripping, signatures of biological iron oxidation were almost completely absent in the trickling filter, suggesting that the presence of methane directly or indirectly promotes chemical iron oxidation. All systems had similar <em>ex-situ</em> manganese oxidation capacities, yet removal occurred only in the submerged filters but not the trickling filter. Ultimately, our results demonstrate that trickling filtration is effective in promoting biological methane oxidation at comparable produced drinking water quality, highlighting its potential for advancing sustainable drinking water production.</div></div>","PeriodicalId":443,"journal":{"name":"Water Research","volume":"279 ","pages":"Article 123450"},"PeriodicalIF":11.4,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143570096","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}

引用次数: 0

Exacerbated anthropogenic water pollution under climate change and urbanization

IF 11.4 1区环境科学与生态学 Q1 ENGINEERING, ENVIRONMENTAL

Water Research

Pub Date : 2025-03-06 DOI: 10.1016/j.watres.2025.123449

Wenyu Yang , Christian Schmidt , Shixue Wu , Ziyong Zhao , Ruifei Li , Zhenyu Wang , Haijun Wang , Pei Hua , Peter Krebs , Jin Zhang

Anthropogenic water pollution severely threatens human society worldwide, yet the water pollution induced by combined sewer overflow (CSO) remains unclear within climate change and urbanization. Hence, this study integrated the general circulation model (GCM) and shared socioeconomic pathway (SSP) projections with water quality modeling, to analyze spatiotemporal patterns and future trends of CSO-induced water pollution under changing environments. Results demonstrated that the given area (Dresden, Germany) encountered significant CSO-induced pollution, with 14,860 kg (95 % confidence interval, CI: 9,040–15,630 kg) of particulate matter (SS), organic compounds (COD, TN, TP), and pharmaceuticals (Carbamazepine, Gabapentin, Ciprofloxacin, Sulfamethoxazole) being discharged annually. Climate change and urbanization exacerbated the severity of CSO-induced pollution, causing the discharged pollutants to reach a maximum annual load of 34,900 kg (CI: 21,400–44,100 kg), with up to 82.19 % of organic compounds and 75.28 % of pharmaceuticals being discharged by the top 25 % of extreme CSOs. GIS-based spatial analysis indicated the regional heterogeneities of CSO-induced pollution, the high-frequency CSOs were predominantly located in highly-impervious areas, while the high-load discharges mainly occurred in densely-populated areas. Scenario analysis revealed stronger temporal variabilities of CSO-induced pollution in the future, with the seasonal anomalies of discharged loads ranging from -86.18 % to 76.89 %. In addition, pharmaceutical pollution exhibited significant uncertainties under changing environments, and the CI of discharged load expanded by up to 131.71 %. The methods and findings herein yielded further insights into water quality management in response to changing environments.

{"title":"Exacerbated anthropogenic water pollution under climate change and urbanization","authors":"Wenyu Yang , Christian Schmidt , Shixue Wu , Ziyong Zhao , Ruifei Li , Zhenyu Wang , Haijun Wang , Pei Hua , Peter Krebs , Jin Zhang","doi":"10.1016/j.watres.2025.123449","DOIUrl":"10.1016/j.watres.2025.123449","url":null,"abstract":"<div><div>Anthropogenic water pollution severely threatens human society worldwide, yet the water pollution induced by combined sewer overflow (CSO) remains unclear within climate change and urbanization. Hence, this study integrated the general circulation model (GCM) and shared socioeconomic pathway (SSP) projections with water quality modeling, to analyze spatiotemporal patterns and future trends of CSO-induced water pollution under changing environments. Results demonstrated that the given area (Dresden, Germany) encountered significant CSO-induced pollution, with 14,860 kg (95 % confidence interval, CI: 9,040–15,630 kg) of particulate matter (SS), organic compounds (COD, TN, TP), and pharmaceuticals (Carbamazepine, Gabapentin, Ciprofloxacin, Sulfamethoxazole) being discharged annually. Climate change and urbanization exacerbated the severity of CSO-induced pollution, causing the discharged pollutants to reach a maximum annual load of 34,900 kg (CI: 21,400–44,100 kg), with up to 82.19 % of organic compounds and 75.28 % of pharmaceuticals being discharged by the top 25 % of extreme CSOs. GIS-based spatial analysis indicated the regional heterogeneities of CSO-induced pollution, the high-frequency CSOs were predominantly located in highly-impervious areas, while the high-load discharges mainly occurred in densely-populated areas. Scenario analysis revealed stronger temporal variabilities of CSO-induced pollution in the future, with the seasonal anomalies of discharged loads ranging from -86.18 % to 76.89 %. In addition, pharmaceutical pollution exhibited significant uncertainties under changing environments, and the CI of discharged load expanded by up to 131.71 %. The methods and findings herein yielded further insights into water quality management in response to changing environments.</div></div>","PeriodicalId":443,"journal":{"name":"Water Research","volume":"280 ","pages":"Article 123449"},"PeriodicalIF":11.4,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143570097","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}

引用次数: 0

Diversity, influential factor, and communication network construction of quorum sensing bacteria in global wastewater treatment plants

IF 11.4 1区环境科学与生态学 Q1 ENGINEERING, ENVIRONMENTAL

Water Research

Pub Date : 2025-03-06 DOI: 10.1016/j.watres.2025.123437

Yong-Chao Wang , Sen Wang , Ya-Hui Lv , Jia-Yi Wang , Wen-Xuan Yang , Ye Deng , Feng Ju , Can Wang

Quorum sensing (QS) is widespread in the microbial world and mediates microbial relationships in communities. However, the existing knowledge is far from a full description of the complex communication-based microbial interactions in engineered ecosystems, i.e., wastewater treatment plants (WWTPs). Herein, we conducted a systematic analysis of the diversity and influential factors of the QS-related microflora through the collection of global 1186 activated sludge microbiome samples. We found that the richness of bacteria associated with the universal bacterial secondary messenger presented the highest in QS system, whereas the bacteria related to the degradation of N-Acyl-homoserine lactones occupied the main position in the quorum quenching system. The community turnover of QS microflora was found more likely to be dominated by the deterministic process, such as the dissolved oxygen and resource availability (the ratio of organic matter to microorganisms). Meanwhile, these QS microflora in turn have a profound impact on the functions of WWTPs, especially multilingual intelligencers involving various language systems, such as Nitrospira. By connecting the signal molecule synthesis and acceptance bacteria, we constructed a QS communication network, which can be a robust tool for initial investigation of signaling molecule-mediated microbial interactions. The above results were further integrated into an online access website, named Quorum Sensing Communication Network in Activated Sludge (QSCNAS) (https://www.qscnas.cn/), which allowed users to browse and capture possible QS-based interactions of target bacterium. This work contributes to the understanding of bacterial communication in WWTPs and provides a platform to help in developing potential regulation strategies.

{"title":"Diversity, influential factor, and communication network construction of quorum sensing bacteria in global wastewater treatment plants","authors":"Yong-Chao Wang , Sen Wang , Ya-Hui Lv , Jia-Yi Wang , Wen-Xuan Yang , Ye Deng , Feng Ju , Can Wang","doi":"10.1016/j.watres.2025.123437","DOIUrl":"10.1016/j.watres.2025.123437","url":null,"abstract":"<div><div>Quorum sensing (QS) is widespread in the microbial world and mediates microbial relationships in communities. However, the existing knowledge is far from a full description of the complex communication-based microbial interactions in engineered ecosystems, i.e., wastewater treatment plants (WWTPs). Herein, we conducted a systematic analysis of the diversity and influential factors of the QS-related microflora through the collection of global 1186 activated sludge microbiome samples. We found that the richness of bacteria associated with the universal bacterial secondary messenger presented the highest in QS system, whereas the bacteria related to the degradation of <em>N</em>-Acyl-homoserine lactones occupied the main position in the quorum quenching system. The community turnover of QS microflora was found more likely to be dominated by the deterministic process, such as the dissolved oxygen and resource availability (the ratio of organic matter to microorganisms). Meanwhile, these QS microflora in turn have a profound impact on the functions of WWTPs, especially multilingual intelligencers involving various language systems, such as <em>Nitrospira</em>. By connecting the signal molecule synthesis and acceptance bacteria, we constructed a QS communication network, which can be a robust tool for initial investigation of signaling molecule-mediated microbial interactions. The above results were further integrated into an online access website, named Quorum Sensing Communication Network in Activated Sludge (QSCNAS) (<span><span>https://www.qscnas.cn/</span><svg><path></path></svg></span>), which allowed users to browse and capture possible QS-based interactions of target bacterium. This work contributes to the understanding of bacterial communication in WWTPs and provides a platform to help in developing potential regulation strategies.</div></div>","PeriodicalId":443,"journal":{"name":"Water Research","volume":"279 ","pages":"Article 123437"},"PeriodicalIF":11.4,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143550522","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}

引用次数: 0

Efficient antibiotic tetracycline degradation and toxicity abatement via the perovskite-type CaFexNi1-xO3 assisted heterogeneous electro-Fenton system

IF 11.4 1区环境科学与生态学 Q1 ENGINEERING, ENVIRONMENTAL

Water Research

Pub Date : 2025-03-06 DOI: 10.1016/j.watres.2025.123432

Yuling Liang , Aochen Feng , Naif Abdullah Al-Dhabi , Jing Zhang , Wenle Xing , Tao Chen , Yuxuan Han , Guangming Zeng , Lin Tang , Wangwang Tang

As one of the emerging contaminants, antibiotics are posing a great threat to the human health and environment, which requires effective treatment methods. Heterogeneous electro-Fenton is a promising technique for organic contaminant elimination, but preparation of an appropriate heterogeneous electro-Fenton catalyst still remains challenging. In this work, the feasibility of perovskite-type CaFe_xNi_1-xO₃ as heterogeneous electro-Fenton catalyst for tetracycline (TC) removal and toxicity abatement has been explored. It was found that, among the examined CaFe_xNi_1-xO₃ catalysts with different Ni doping amount, CaFe_3/4Ni_1/4O₃ exhibited the best performance, achieving 92.1 % TC removal within 30 min without pH adjustment in the presence of 0.05 M Na₂SO₄ electrolyte. Choosing Cl⁻-containing electrolyte enabled further improvement towards TC elimination. In addition, the CaFe_3/4Ni_1/4O₃ based heterogeneous electro-Fenton system presented other advantages including good recyclability and universal applicability, and significant toxicity reduction (verified via both ECOSAR simulation and soybean germination test). The TC degradation pathways were elucidated through identification of intermediate products and DFT calculations. Mechanism investigations revealed that there existed a strong synergy between Fe and Ni, and ·OH and ·O₂⁻ played the primary roles in the system while ¹O₂ played an auxiliary role. This study presented a promising heterogeneous electro-Fenton catalyst for degradation of antibiotics such as tetracycline.

{"title":"Efficient antibiotic tetracycline degradation and toxicity abatement via the perovskite-type CaFexNi1-xO3 assisted heterogeneous electro-Fenton system","authors":"Yuling Liang , Aochen Feng , Naif Abdullah Al-Dhabi , Jing Zhang , Wenle Xing , Tao Chen , Yuxuan Han , Guangming Zeng , Lin Tang , Wangwang Tang","doi":"10.1016/j.watres.2025.123432","DOIUrl":"10.1016/j.watres.2025.123432","url":null,"abstract":"<div><div>As one of the emerging contaminants, antibiotics are posing a great threat to the human health and environment, which requires effective treatment methods. Heterogeneous electro-Fenton is a promising technique for organic contaminant elimination, but preparation of an appropriate heterogeneous electro-Fenton catalyst still remains challenging. In this work, the feasibility of perovskite-type CaFe<sub>x</sub>Ni<sub>1-x</sub>O<sub>3</sub> as heterogeneous electro-Fenton catalyst for tetracycline (TC) removal and toxicity abatement has been explored. It was found that, among the examined CaFe<sub>x</sub>Ni<sub>1-x</sub>O<sub>3</sub> catalysts with different Ni doping amount, CaFe<sub>3/4</sub>Ni<sub>1/4</sub>O<sub>3</sub> exhibited the best performance, achieving 92.1 % TC removal within 30 min without pH adjustment in the presence of 0.05 M Na<sub>2</sub>SO<sub>4</sub> electrolyte. Choosing Cl<sup>−</sup>-containing electrolyte enabled further improvement towards TC elimination. In addition, the CaFe<sub>3/4</sub>Ni<sub>1/4</sub>O<sub>3</sub> based heterogeneous electro-Fenton system presented other advantages including good recyclability and universal applicability, and significant toxicity reduction (verified via both ECOSAR simulation and soybean germination test). The TC degradation pathways were elucidated through identification of intermediate products and DFT calculations. Mechanism investigations revealed that there existed a strong synergy between Fe and Ni, and ·OH and ·O<sub>2</sub><sup>−</sup> played the primary roles in the system while <sup>1</sup>O<sub>2</sub> played an auxiliary role. This study presented a promising heterogeneous electro-Fenton catalyst for degradation of antibiotics such as tetracycline.</div></div>","PeriodicalId":443,"journal":{"name":"Water Research","volume":"279 ","pages":"Article 123432"},"PeriodicalIF":11.4,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143550658","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}

引用次数: 0

The bidirectional matter transfer in adsorption-promoted photocatalytic ozonation system derived by triazine nanosheets-heptazine nanotubes homojunction composite biochar

IF 11.4 1区环境科学与生态学 Q1 ENGINEERING, ENVIRONMENTAL

Water Research

Pub Date : 2025-03-06 DOI: 10.1016/j.watres.2025.123444

Benjie Zhu , Jialiang Liu , Yuxiang Shen , Lingyu Liu , Fang Liu

Heterogeneous catalytic ozonation (HCO) process is an efficiency and eco-friendly solution to the growing challenge of water purification, yet is challenging by O₃ utilization, pollutants selectivity, and matter transfer resistance. Herein, adsorption-promoted photocatalytic ozonation (HCO/PO_AP) system was constructed derived by triazine nanosheets-heptazine nanotubes homojunction carbon nitride composite Enteromorpha prolifera derived biochar (CN_Th-St/EpC) to provide a targeted solution for the refractory organic pollutants treatment. In the HCO/PO_AP system, the adsorption sites predominantly reside on EpC, while the catalytic sites are primarily located on CN. The construction of efficient transport channels is facilitated by the induction of triazine structures from amorphous C, N compounds along the edges of heptazine. This leads to the independent yet closely interconnected process of inward transfer of pollutants and outward transfer of active species, confining reactions to a bidirectional transfer channel. This strategic confinement significantly amplifies the performance of HCO/PO_AP system. Specifically, the removal rates are 80 % for TC and 94 % for PNP in 30 min with almost entirely harmless or non-toxic degradation products, and mark a 56 % and 77 % enhancement over O₃ system, respectively. Moreover, the HCO/PO_AP system demonstrates exceptional efficacy in treating dissolved organic matter, chemical oxygen demand (COD), and ultraviolet absorbance at 254 nm (UV₂₅₄) in diverse actual wastewater. This study highlights the potential of HCO/PO_AP process in efficient water purification, and provides mechanistic insights into the bidirectional matter transfer during the contaminants remove.

{"title":"The bidirectional matter transfer in adsorption-promoted photocatalytic ozonation system derived by triazine nanosheets-heptazine nanotubes homojunction composite biochar","authors":"Benjie Zhu , Jialiang Liu , Yuxiang Shen , Lingyu Liu , Fang Liu","doi":"10.1016/j.watres.2025.123444","DOIUrl":"10.1016/j.watres.2025.123444","url":null,"abstract":"<div><div>Heterogeneous catalytic ozonation (HCO) process is an efficiency and eco-friendly solution to the growing challenge of water purification, yet is challenging by O<sub>3</sub> utilization, pollutants selectivity, and matter transfer resistance. Herein, adsorption-promoted photocatalytic ozonation (HCO/PO<sub>AP</sub>) system was constructed derived by triazine nanosheets-heptazine nanotubes homojunction carbon nitride composite Enteromorpha prolifera derived biochar (CN<sub>Th-St</sub>/EpC) to provide a targeted solution for the refractory organic pollutants treatment. In the HCO/PO<sub>AP</sub> system, the adsorption sites predominantly reside on EpC, while the catalytic sites are primarily located on CN. The construction of efficient transport channels is facilitated by the induction of triazine structures from amorphous C, N compounds along the edges of heptazine. This leads to the independent yet closely interconnected process of inward transfer of pollutants and outward transfer of active species, confining reactions to a bidirectional transfer channel. This strategic confinement significantly amplifies the performance of HCO/PO<sub>AP</sub> system. Specifically, the removal rates are 80 % for TC and 94 % for PNP in 30 min with almost entirely harmless or non-toxic degradation products, and mark a 56 % and 77 % enhancement over O<sub>3</sub> system, respectively. Moreover, the HCO/PO<sub>AP</sub> system demonstrates exceptional efficacy in treating dissolved organic matter, chemical oxygen demand (COD), and ultraviolet absorbance at 254 nm (UV<sub>254</sub>) in diverse actual wastewater. This study highlights the potential of HCO/PO<sub>AP</sub> process in efficient water purification, and provides mechanistic insights into the bidirectional matter transfer during the contaminants remove.</div></div>","PeriodicalId":443,"journal":{"name":"Water Research","volume":"279 ","pages":"Article 123444"},"PeriodicalIF":11.4,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143570095","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}

引用次数: 0

Insights into in-situ free nitrous acid induced extracellular polymeric substances changes and membrane fouling mitigation in a nitritation membrane bioreactor

IF 11.4 1区环境科学与生态学 Q1 ENGINEERING, ENVIRONMENTAL

Water Research

Pub Date : 2025-03-05 DOI: 10.1016/j.watres.2025.123446

Yishuai Jiang , Xiaoyuan Zhang , Hiroshige Shiota , Wun Jern Ng

This study investigated the effectiveness of free nitrous acid (FNA) on mitigating membrane fouling, with the associated mechanisms, in two nitritation membrane bioreactors (MBRs) operated with Nitrosomonas-enriched culture. Results showed that FNA stress, regulated by pH and nitrite concentration, maintained a low-level fouling as opposed to the control MBR where trans-membrane pressure (TMP) exceeded 30 kPa. Compared to the control MBR, production of biofilm in the FNA stressed MBR was reduced by 68.1% in terms of mass and 78.2% in terms of thickness. Suspended biomass and biofilm extracellular polymeric substances (EPS) characterized by liquid chromatography (LC-OCD-OND) indicated FNA stress reduced the amount of low molecular weight neutrals and hydrophobic dissolved organic carbon. These components would have had high fouling potential. Excitation emission matrix (EEM) fluorescence contours indicated that exposure to FNA stimulated the production of tyrosine-like proteins but reduced those of SMP like and humic acid-like substances. This could have affected the adhesion between bacteria and membrane and so contributed to the reduced biofilm and fouling. X-ray photoelectron spectroscopy (XPS) analysis revealed marked differences in intensities of the main functionalities in the EPS for both sludge and biofilm, due to the oxidative effect of FNA, e.g. FNA stress resulted in more aliphatic C-OH, amines and amides while the control had more C=O, amino acids and amino sugars. This study showed that in-situ generated FNA could be employed to mitigate membrane fouling effectively via its biocidal and oxidative effect.

{"title":"Insights into in-situ free nitrous acid induced extracellular polymeric substances changes and membrane fouling mitigation in a nitritation membrane bioreactor","authors":"Yishuai Jiang , Xiaoyuan Zhang , Hiroshige Shiota , Wun Jern Ng","doi":"10.1016/j.watres.2025.123446","DOIUrl":"10.1016/j.watres.2025.123446","url":null,"abstract":"<div><div>This study investigated the effectiveness of free nitrous acid (FNA) on mitigating membrane fouling, with the associated mechanisms, in two nitritation membrane bioreactors (MBRs) operated with <em>Nitrosomonas-</em>enriched culture. Results showed that FNA stress, regulated by pH and nitrite concentration, maintained a low-level fouling as opposed to the control MBR where trans-membrane pressure (TMP) exceeded 30 kPa. Compared to the control MBR, production of biofilm in the FNA stressed MBR was reduced by 68.1% in terms of mass and 78.2% in terms of thickness. Suspended biomass and biofilm extracellular polymeric substances (EPS) characterized by liquid chromatography (LC-OCD-OND) indicated FNA stress reduced the amount of low molecular weight neutrals and hydrophobic dissolved organic carbon. These components would have had high fouling potential. Excitation emission matrix (EEM) fluorescence contours indicated that exposure to FNA stimulated the production of tyrosine-like proteins but reduced those of SMP like and humic acid-like substances. This could have affected the adhesion between bacteria and membrane and so contributed to the reduced biofilm and fouling. X-ray photoelectron spectroscopy (XPS) analysis revealed marked differences in intensities of the main functionalities in the EPS for both sludge and biofilm, due to the oxidative effect of FNA, e.g. FNA stress resulted in more aliphatic C-OH, amines and amides while the control had more C=O, amino acids and amino sugars. This study showed that <em>in-situ</em> generated FNA could be employed to mitigate membrane fouling effectively via its biocidal and oxidative effect.</div></div>","PeriodicalId":443,"journal":{"name":"Water Research","volume":"279 ","pages":"Article 123446"},"PeriodicalIF":11.4,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143560880","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}

引用次数: 0

Aging behaviors intensify the impacts of microplastics on nitrate bioreduction-driven nitrogen cycling in freshwater sediments

IF 11.4 1区环境科学与生态学 Q1 ENGINEERING, ENVIRONMENTAL

Water Research

Pub Date : 2025-03-05 DOI: 10.1016/j.watres.2025.123448

Yuecheng She , Liying Wu , Xin Qi , Siyu Sun , Zhengkui Li

Microplastics (MPs) inevitably undergo aging processes in natural environments; however, how aging behaviors influence the interactions between MPs exposures and nitrate bioreduction in freshwater sediments remains poorly understood. Here, we explored the distinct impacts of virgin and aged MPs (polystyrene (PS) and polylactic acid (PLA)) on nitrate bioreduction processes in lake sediments through a long-term microcosm experiment utilizing the ¹⁵N isotope tracing technique and molecular analysis. Compared to virgin MPs, aged PLA significantly increased the rates of denitrification, anaerobic ammonium oxidation (anammox), and dissimilatory nitrate reduction to ammonium (DNRA) (p < 0.05), facilitating sediment nitrogen loss, while aged PS only significantly improved the rates of DNRA by 272–297 % and contributed to nitrogen retention in sediments. Metagenomic sequencing demonstrated that a more significant enrichment of functional genes responsible for nitrate bioreduction pathways occurred with aged MPs exposures than with virgin MPs. By combining analyses of MPs aging traits and the key drivers of nitrate bioreduction, we revealed that aging behaviors directly regulated sediment nutrient status (e.g., DOC/NO_x^– ratio) and microbiological properties (from genes to bacteria), thereby further determining the activity of nitrate bioreduction. This work provides new insights into the impacts of aged MPs on sediment nitrate reduction and highlights the role of MPs aging in future assessments of long-term MPs pollution in freshwater ecosystems.

{"title":"Aging behaviors intensify the impacts of microplastics on nitrate bioreduction-driven nitrogen cycling in freshwater sediments","authors":"Yuecheng She , Liying Wu , Xin Qi , Siyu Sun , Zhengkui Li","doi":"10.1016/j.watres.2025.123448","DOIUrl":"10.1016/j.watres.2025.123448","url":null,"abstract":"<div><div>Microplastics (MPs) inevitably undergo aging processes in natural environments; however, how aging behaviors influence the interactions between MPs exposures and nitrate bioreduction in freshwater sediments remains poorly understood. Here, we explored the distinct impacts of virgin and aged MPs (polystyrene (PS) and polylactic acid (PLA)) on nitrate bioreduction processes in lake sediments through a long-term microcosm experiment utilizing the <sup>15</sup>N isotope tracing technique and molecular analysis. Compared to virgin MPs, aged PLA significantly increased the rates of denitrification, anaerobic ammonium oxidation (anammox), and dissimilatory nitrate reduction to ammonium (DNRA) (<em>p</em> < 0.05), facilitating sediment nitrogen loss, while aged PS only significantly improved the rates of DNRA by 272–297 % and contributed to nitrogen retention in sediments. Metagenomic sequencing demonstrated that a more significant enrichment of functional genes responsible for nitrate bioreduction pathways occurred with aged MPs exposures than with virgin MPs. By combining analyses of MPs aging traits and the key drivers of nitrate bioreduction, we revealed that aging behaviors directly regulated sediment nutrient status (e.g., DOC/NO<sub>x</sub><sup>–</sup> ratio) and microbiological properties (from genes to bacteria), thereby further determining the activity of nitrate bioreduction. This work provides new insights into the impacts of aged MPs on sediment nitrate reduction and highlights the role of MPs aging in future assessments of long-term MPs pollution in freshwater ecosystems.</div></div>","PeriodicalId":443,"journal":{"name":"Water Research","volume":"279 ","pages":"Article 123448"},"PeriodicalIF":11.4,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143560881","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}

引用次数: 0

Tidal fluctuations induce accumulation and transformation of seawater Cr(Ⅵ) in coastal sediments

IF 11.4 1区环境科学与生态学 Q1 ENGINEERING, ENVIRONMENTAL

Water Research

Pub Date : 2025-03-05 DOI: 10.1016/j.watres.2025.123382

Xuanang Gong , Gaoyang Xu , Chengpeng Yuan , Xiaoyun Xu , Jun Wang , Xinde Cao

Tidal fluctuations play a critical role in regulating the transport and fate of contaminants in coastal environments. This study explored the dynamic redistribution of chromium (Cr) from seawater to sediment under tidal influence, as well as the accumulation and transformation of Cr in sediment through laboratory experiments and numerical simulations. After 35 tidal cycles, Cr concentrations in seawater declined rapidly and stabilized at approximately 27 % of the initial level. Notably, Cr migrated into sediment, ultimately accumulating in the bottom layer. Colloidal particles (350–800 nm) composed of clay minerals served as the primary transport vectors for Cr within sediment. During tidal fluctuations, 94.5 %–98.2 % of Cr(VI) in sediment was reduced to Cr(III), predominantly mediated by Fe(II) in the top sediment and by sulfur-reducing bacteria in the bottom layers. Consistent with experimental findings, numerical reactive transport modeling demonstrated that Cr(III) initially peaked in the middle sediment layer before stabilizing in the bottom layer, whereas Cr(VI) remained confined to the top layer. These findings elucidate tide-induced mobilization and natural reduction mechanisms governing Cr-contaminated seawater infiltration into sediment, offering novel insights into the fate of Cr discharged from coastal wastewater sources within seawater-sediment systems.

{"title":"Tidal fluctuations induce accumulation and transformation of seawater Cr(Ⅵ) in coastal sediments","authors":"Xuanang Gong , Gaoyang Xu , Chengpeng Yuan , Xiaoyun Xu , Jun Wang , Xinde Cao","doi":"10.1016/j.watres.2025.123382","DOIUrl":"10.1016/j.watres.2025.123382","url":null,"abstract":"<div><div>Tidal fluctuations play a critical role in regulating the transport and fate of contaminants in coastal environments. This study explored the dynamic redistribution of chromium (Cr) from seawater to sediment under tidal influence, as well as the accumulation and transformation of Cr in sediment through laboratory experiments and numerical simulations. After 35 tidal cycles, Cr concentrations in seawater declined rapidly and stabilized at approximately 27 % of the initial level. Notably, Cr migrated into sediment, ultimately accumulating in the bottom layer. Colloidal particles (350–800 nm) composed of clay minerals served as the primary transport vectors for Cr within sediment. During tidal fluctuations, 94.5 %–98.2 % of Cr(VI) in sediment was reduced to Cr(III), predominantly mediated by Fe(II) in the top sediment and by sulfur-reducing bacteria in the bottom layers. Consistent with experimental findings, numerical reactive transport modeling demonstrated that Cr(III) initially peaked in the middle sediment layer before stabilizing in the bottom layer, whereas Cr(VI) remained confined to the top layer. These findings elucidate tide-induced mobilization and natural reduction mechanisms governing Cr-contaminated seawater infiltration into sediment, offering novel insights into the fate of Cr discharged from coastal wastewater sources within seawater-sediment systems.</div></div>","PeriodicalId":443,"journal":{"name":"Water Research","volume":"278 ","pages":"Article 123382"},"PeriodicalIF":11.4,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143549530","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}

引用次数: 0

A coupled optimized hedging rule-based reservoir operation and hydrodynamic model framework for riverine flood risk management

IF 11.4 1区环境科学与生态学 Q1 ENGINEERING, ENVIRONMENTAL

Water Research

Pub Date : 2025-03-05 DOI: 10.1016/j.watres.2025.123443

Ashrumochan Mohanty , Bhabagrahi Sahoo , Ravindra Vitthal Kale

Long-term changes in reservoir inflow due to climate change and human interferences violate the assumptions of hydrologic stationarity, especially in the reservoir operation during high flood season for managing the downstream critical levee (DCL) sections from overtopping. Utilization of uncertain inflow forecast into a reservoir using the operating rule curve of certain forecast horizon reflects the challenges imposed by nonstationary conditions, downstream flood intensification with spatiotemporally distributed lateral flux and floodplain dynamics. Addressing these issues, this study develops four hierarchical frameworks considering single-stage hedging (1SH) and two-stage hedging (2SH) rules-based reservoir operation models optimized with Particle Swarm Optimization (PSO) and informed with rating curve uncertainty at DCL section. Further, these two frameworks are coupled with HEC-RAS-2D (H2D) hydrodynamic model to reduce the existing flood risk at DCL section. The efficiency of the advocated 1SH-PSO, 2SH-PSO, 1SH-PSOH2D and 2SH-PSOH2D are tested in the Rengali reservoir on the Brahmani River in eastern India. The inflow forecasts into the reservoir are simulated by the coupled SWAT-Pothole and Wavelet-based Bidirectional Long-Short-Term Memory (WBiLSTM) models forced with the bias-corrected GFS weather forecasts with up to 10 days’ lead-times. The results demonstrate that the best-performing 2SH-PSOH2D framework-based reservoir operation could reduce the average peak flow depth at the DCL station by 21 % from the baseline with an average reduction in levee failure risk by 22.28 % leading to effective management of high flood events. This advocated framework could be used in other reservoir systems worldwide in reducing the downstream flood hazards through enhanced reservoir operation.

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引用次数: 0

Impact of organic carbon-Mn oxide interactions on colloid stability and contaminant metals in aquatic environments

IF 12.8 1区环境科学与生态学 Q1 ENGINEERING, ENVIRONMENTAL

Water Research

Pub Date : 2025-03-05 DOI: 10.1016/j.watres.2025.123445

Qianqian Li, Debra Hausladen

Interactions between organic carbon and Mn oxides can lead to the formation of C-Mn colloids, which play a crucial role in regulating Mn mobility in the environment. Despite the significance of these interactions, however, the impact of C-Mn oxide interactions on the mobility of these colloids, particularly in the presence of contaminant metals, remains poorly understood. This study investigated the aggregation kinetics of C-Mn colloids formed through the reaction between humic acid and Mn oxides at three C:Mn molar ratios in the presence of divalent cations (Ca²⁺ and Mg²⁺). The introduction of organic carbon increased the stability (i.e., ability to resist aggregation) of C-Mn colloids compared to pure Mn(IV) colloids, as reflected in the higher critical coagulation concentration (CCC). As C:Mn molar ratios rose from 0.5 to 3 during colloid formation, the CCCs for the resulting C-Mn colloids increased from 3.6 mM to 7.2 mM Ca²⁺. However, at the highest C:Mn ratio (C:Mn=15), the CCCs decreased slightly to 7.0 mM Ca²⁺, with a similar trend observed for Mg²⁺. The stability of C-Mn colloids was affected by their characteristics, including electrostatic repulsion, surface functional groups, and Mn(II) content, which resulted upon reaction with dissolved organic carbon. Based on CCCs, C-Mn colloids were most stable in the presence of Mn²⁺ (6.9 mM), followed by Co²⁺ (5.9 mM), Zn²⁺ (2.7 mM), and Cd²⁺ (1.9 mM). The capacity of contaminant metals to destabilize C-Mn colloids followed the reverse order, with Cd²⁺ having the greatest destabilizing effect. Variations among the different metals were influenced by factors such as atomic radius, hydration shell, electronegativity, and electrostatic repulsion. These results provide new insights into the aggregation behavior of C-Mn colloids and the mechanisms controlling the fate and mobility of associated contaminant metals. This knowledge has important implications for understanding contaminant transport in natural waters and optimizing water treatment processes.

{"title":"Impact of organic carbon-Mn oxide interactions on colloid stability and contaminant metals in aquatic environments","authors":"Qianqian Li, Debra Hausladen","doi":"10.1016/j.watres.2025.123445","DOIUrl":"https://doi.org/10.1016/j.watres.2025.123445","url":null,"abstract":"Interactions between organic carbon and Mn oxides can lead to the formation of C-Mn colloids, which play a crucial role in regulating Mn mobility in the environment. Despite the significance of these interactions, however, the impact of C-Mn oxide interactions on the mobility of these colloids, particularly in the presence of contaminant metals, remains poorly understood. This study investigated the aggregation kinetics of C-Mn colloids formed through the reaction between humic acid and Mn oxides at three C:Mn molar ratios in the presence of divalent cations (Ca<sup>2+</sup> and Mg<sup>2+</sup>). The introduction of organic carbon increased the stability (i.e., ability to resist aggregation) of C-Mn colloids compared to pure Mn(IV) colloids, as reflected in the higher critical coagulation concentration (CCC). As C:Mn molar ratios rose from 0.5 to 3 during colloid formation, the CCCs for the resulting C-Mn colloids increased from 3.6 mM to 7.2 mM Ca<sup>2+</sup>. However, at the highest C:Mn ratio (C:Mn=15), the CCCs decreased slightly to 7.0 mM Ca<sup>2+</sup>, with a similar trend observed for Mg<sup>2+</sup>. The stability of C-Mn colloids was affected by their characteristics, including electrostatic repulsion, surface functional groups, and Mn(II) content, which resulted upon reaction with dissolved organic carbon. Based on CCCs, C-Mn colloids were most stable in the presence of Mn<sup>2+</sup> (6.9 mM), followed by Co<sup>2+</sup> (5.9 mM), Zn<sup>2+</sup> (2.7 mM), and Cd<sup>2+</sup> (1.9 mM). The capacity of contaminant metals to destabilize C-Mn colloids followed the reverse order, with Cd<sup>2+</sup> having the greatest destabilizing effect. Variations among the different metals were influenced by factors such as atomic radius, hydration shell, electronegativity, and electrostatic repulsion. These results provide new insights into the aggregation behavior of C-Mn colloids and the mechanisms controlling the fate and mobility of associated contaminant metals. This knowledge has important implications for understanding contaminant transport in natural waters and optimizing water treatment processes.","PeriodicalId":443,"journal":{"name":"Water Research","volume":"3 1","pages":""},"PeriodicalIF":12.8,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143546850","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}

引用次数: 0