Pub Date : 2025-04-07DOI: 10.1016/j.watres.2025.123597
Degang Ma, Junjie Hu, Miaomiao Zhao, Li Chen, Zhiyang Gong, Zeying Sun
Aged oily sludge (AOS) exhibits more challenging properties compared to ordinary oily sludge, making modification treatments essential for improving dewatering efficiency. This study innovatively employs citric acid (CA) as a pretreatment agent for AOS and combines pressure filtration (PF) and electro-dewatering (EDW) to conduct volume reduction experiments, while investigating the dewatering mechanism of CA pretreatment. Under a pressure of 75 kPa, the AOS moisture content decreased slightly from 80.12% to 78.00%, while the addition of 0.02g CA/g AOS further reduced it to 71.69%. Under conditions of 25 kPa and 25 V/cm, EDW lowered the moisture content to 47.36%, achieving faster average dewatering rate of 0.086 g/s. This study investigated the oil and water distribution within sludge cake layers, analyzed their migration during EDW, and explained the anodic drying phenomenon. Engineering applicability was assessed through energy consumption and calorific value analyses. Mechanistic insights revealed oil component changes, highlighting the roles of surfactants, electric field forces, pH, and temperature. Formula-based calculations were also conducted for field-driven processes. This study presents an innovative deep dewatering technology for AOS, investigating the dewatering mechanism from various perspectives, including demulsification, electric field, pH, and thermal effects. Additionally, it evaluates the energy consumption and economic cost, providing a theoretical foundation for its engineering applicability and offering new perspectives for the treatment and disposal of AOS.
{"title":"Modification of aged oily sludge (AOS) through pressure filtration and electro-dewatering methods under citric acid (CA) pretreatment","authors":"Degang Ma, Junjie Hu, Miaomiao Zhao, Li Chen, Zhiyang Gong, Zeying Sun","doi":"10.1016/j.watres.2025.123597","DOIUrl":"https://doi.org/10.1016/j.watres.2025.123597","url":null,"abstract":"Aged oily sludge (AOS) exhibits more challenging properties compared to ordinary oily sludge, making modification treatments essential for improving dewatering efficiency. This study innovatively employs citric acid (CA) as a pretreatment agent for AOS and combines pressure filtration (PF) and electro-dewatering (EDW) to conduct volume reduction experiments, while investigating the dewatering mechanism of CA pretreatment. Under a pressure of 75 kPa, the AOS moisture content decreased slightly from 80.12% to 78.00%, while the addition of 0.02g CA/g AOS further reduced it to 71.69%. Under conditions of 25 kPa and 25 V/cm, EDW lowered the moisture content to 47.36%, achieving faster average dewatering rate of 0.086 g/s. This study investigated the oil and water distribution within sludge cake layers, analyzed their migration during EDW, and explained the anodic drying phenomenon. Engineering applicability was assessed through energy consumption and calorific value analyses. Mechanistic insights revealed oil component changes, highlighting the roles of surfactants, electric field forces, pH, and temperature. Formula-based calculations were also conducted for field-driven processes. This study presents an innovative deep dewatering technology for AOS, investigating the dewatering mechanism from various perspectives, including demulsification, electric field, pH, and thermal effects. Additionally, it evaluates the energy consumption and economic cost, providing a theoretical foundation for its engineering applicability and offering new perspectives for the treatment and disposal of AOS.","PeriodicalId":443,"journal":{"name":"Water Research","volume":"18 1","pages":""},"PeriodicalIF":12.8,"publicationDate":"2025-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143789822","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}
Bacterial resistance to chlorine disinfectant reduces its effectiveness in killing pathogenic bacteria and poses a severe threat to environmental and health safety. The interaction between bacteria and phages is the most frequent biological activity in Earth's biosphere, but little is known about what role and mechanism phages play in the resistance of bacterial communities to chlorine disinfectants. Here, we investigated the changes in the abundance, activity and function of the bacterial-phage community under the effect of chlorine disinfectants in a 92-day running anaerobic-anoxic-oxic system, using metagenomics and metatranscriptomics sequencing. We found that transcriptional activities of both bacteria and phage are highly sensitive to chlorine disinfectants, although their relative abundance was not obviously altered. The increase in both phage diversity and the ratio of temperate to lytic phages’ average activity indicated phages, especially temperate, could play a crucial role in the response to chlorine disinfectants. Interestingly, the phages that carry chlorine resistance genes (CRGs) were the drivers of the phage and microbial community when chlorine disinfectants were present, but they followed the dynamics of community in the absence of chlorine disinfectants. Based on the association bipartite network, we further found that phages directly mediated the horizontal transfer of CRGs among bacteria, facilitating the spread of CRGs in the bacterial community. Moreover, the 4 CRGs related to cell wall repair, redox balance regulation, and efflux pumps that were carried by the phages but lacking in the hosts suggest the potential compensatory effects of the phage for the chlorine resistance of their hosts. Our findings reveal the important role of phages in improving the resistance of bacterial communities to chlorine disinfectants, providing a new perspective on the co-evolution of phages and bacteria to adapt to environments.
{"title":"New perspectives on bacterial chlorine resistance: Phages encoding chlorine resistance genes improve bacterial adaptation","authors":"Jia Wang, Yibo Zhang, Qiyue Meng, Ziyu Hu, Jie Fu, Chenyuan Dang","doi":"10.1016/j.watres.2025.123607","DOIUrl":"10.1016/j.watres.2025.123607","url":null,"abstract":"<div><div>Bacterial resistance to chlorine disinfectant reduces its effectiveness in killing pathogenic bacteria and poses a severe threat to environmental and health safety. The interaction between bacteria and phages is the most frequent biological activity in Earth's biosphere, but little is known about what role and mechanism phages play in the resistance of bacterial communities to chlorine disinfectants. Here, we investigated the changes in the abundance, activity and function of the bacterial-phage community under the effect of chlorine disinfectants in a 92-day running anaerobic-anoxic-oxic system, using metagenomics and metatranscriptomics sequencing. We found that transcriptional activities of both bacteria and phage are highly sensitive to chlorine disinfectants, although their relative abundance was not obviously altered. The increase in both phage diversity and the ratio of temperate to lytic phages’ average activity indicated phages, especially temperate, could play a crucial role in the response to chlorine disinfectants. Interestingly, the phages that carry chlorine resistance genes (CRGs) were the drivers of the phage and microbial community when chlorine disinfectants were present, but they followed the dynamics of community in the absence of chlorine disinfectants. Based on the association bipartite network, we further found that phages directly mediated the horizontal transfer of CRGs among bacteria, facilitating the spread of CRGs in the bacterial community. Moreover, the 4 CRGs related to cell wall repair, redox balance regulation, and efflux pumps that were carried by the phages but lacking in the hosts suggest the potential compensatory effects of the phage for the chlorine resistance of their hosts. Our findings reveal the important role of phages in improving the resistance of bacterial communities to chlorine disinfectants, providing a new perspective on the co-evolution of phages and bacteria to adapt to environments.</div></div>","PeriodicalId":443,"journal":{"name":"Water Research","volume":"282 ","pages":"Article 123607"},"PeriodicalIF":11.4,"publicationDate":"2025-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143789770","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 : 2025-04-06DOI: 10.1016/j.watres.2025.123605
Linzhu Du , Wei Guo , Dongyue Li , Martin R. Tillotson , Yuhan Zhu , Junhui Yue , Jun Li , Shouliang Huo , Yue Gao , Xu Zhao
Continued seawater incursion significantly affects the fate of pollutants in coastal estuaries, yet understanding of the in-situ behavior of endocrine-disrupting compounds (EDCs) in these areas remains limited. The distribution, transport and microbial response of two model EDCs, bisphenol A (BPA) and nonylphenol (NP), in three estuarine zones of slight (SZ), moderate (MZ) and complete (CZ) seawater incursion were investigated in-situ. Results showed seawater incursion reshaped the environmental gradients of the coastal estuaries on a spatial scale. Varying salinity gradient and tidal hydrodynamic conditions altered the dependence of EDCs on organic carbon, and promoted the release of accumulated EDCs from estuarine sediments resulting in the lowest residues of BPA (2.74 ± 0.76 μg/kg) and NP (10.25 ± 5.86 μg/kg) in the MZ. The resupply potential of BPA (R = 0.171 ± 0.058) and NP (R = 0.107 ± 0.015) from sediment to porewater was significantly higher in the SZ than in other zones (p < 0.001), due to both higher contaminant accumulation in this zone and inhibited resupply in MZ and CZ caused by seawater incursion. Furthermore, seawater incursion significantly reduced the microbial community diversity in the CZ (p < 0.001), being dominated by Vibrio (67.00 ± 1.13 %), and accordingly weakened the ability to transform organic matter in this region. Based on predicted sea level rise and the transport characteristics of EDCs under increased seawater incursion, it is estimated that the cumulative additional release of BPA and NP in the estuary will reach 1.8 and 1.5 tons by 2100, respectively. In order to mitigate the risk of additional estuarine EDCs release due to seawater incursion, increasing vegetation cover, strict monitoring, and climate policy interventions may be effective strategies.
{"title":"Invisible threats from typical endocrine disrupting compounds in estuarine environments caused by continuing seawater incursion: In-situ evidence of bio-geochemical processes captured by diffusive gradients in thin films","authors":"Linzhu Du , Wei Guo , Dongyue Li , Martin R. Tillotson , Yuhan Zhu , Junhui Yue , Jun Li , Shouliang Huo , Yue Gao , Xu Zhao","doi":"10.1016/j.watres.2025.123605","DOIUrl":"10.1016/j.watres.2025.123605","url":null,"abstract":"<div><div>Continued seawater incursion significantly affects the fate of pollutants in coastal estuaries, yet understanding of the in-situ behavior of endocrine-disrupting compounds (EDCs) in these areas remains limited. The distribution, transport and microbial response of two model EDCs, bisphenol A (BPA) and nonylphenol (NP), in three estuarine zones of slight (SZ), moderate (MZ) and complete (CZ) seawater incursion were investigated in-situ. Results showed seawater incursion reshaped the environmental gradients of the coastal estuaries on a spatial scale. Varying salinity gradient and tidal hydrodynamic conditions altered the dependence of EDCs on organic carbon, and promoted the release of accumulated EDCs from estuarine sediments resulting in the lowest residues of BPA (2.74 ± 0.76 μg/kg) and NP (10.25 ± 5.86 μg/kg) in the MZ. The resupply potential of BPA (<em>R</em> = 0.171 ± 0.058) and NP (<em>R</em> = 0.107 ± 0.015) from sediment to porewater was significantly higher in the SZ than in other zones (<em>p</em> < 0.001), due to both higher contaminant accumulation in this zone and inhibited resupply in MZ and CZ caused by seawater incursion. Furthermore, seawater incursion significantly reduced the microbial community diversity in the CZ (<em>p</em> < 0.001), being dominated by <em>Vibrio</em> (67.00 ± 1.13 %), and accordingly weakened the ability to transform organic matter in this region. Based on predicted sea level rise and the transport characteristics of EDCs under increased seawater incursion, it is estimated that the cumulative additional release of BPA and NP in the estuary will reach 1.8 and 1.5 tons by 2100, respectively. In order to mitigate the risk of additional estuarine EDCs release due to seawater incursion, increasing vegetation cover, strict monitoring, and climate policy interventions may be effective strategies.</div></div>","PeriodicalId":443,"journal":{"name":"Water Research","volume":"281 ","pages":"Article 123605"},"PeriodicalIF":11.4,"publicationDate":"2025-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143784844","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 : 2025-04-06DOI: 10.1016/j.watres.2025.123604
Meicen Liu , Isamu Umeda , Sandeep Kumar , Zhiwu Wang , Yi Zheng
Aerobic fermentation is a simple and environmentally friendly method to treat and recover nutrients from hydrothermal liquefaction aqueous phase (HTLAP). This study evaluated the chemical composition and aerobic biodegradability of HTLAP derived from corn stover under different hydrothermal liquefaction (HTL) conditions. The compositions of HTLAP followed specific patterns corresponding to HTL reaction severity, with high severity leading to increased concentrations of certain phenolic compounds. The elevated phenolics contributed to stronger inhibition of HTLAP on Aspergillus niger and Rhodococcus jostii. The half-maximal inhibitory concentration (IC50) of HTLAP for both microbes can be well predicted by linear regression models with HTL reaction temperature and time as the input variables, while corn stover solid loading showed no significant effect on IC50 and was not included in the models. Furthermore, aerobic fermentation with A. niger followed by R. jostii was demonstrated to be a versatile treatment process for corn stover HTLAP derived from a broad range of HTL conditions, achieving 45–70 % of COD removal. This research provides a quantitative understanding of the relationships between HTL reaction conditions, HTLAP composition, and aerobic biodegradability via A. niger and R. jostii, laying the foundation for integrating HTLAP aerobic fermentation into the HTL system, potentially enhancing its overall cost-efficiency and sustainability.
{"title":"Impact of corn stover hydrothermal liquefaction conditions on the chemical composition and aerobic fermentation of the aqueous phase","authors":"Meicen Liu , Isamu Umeda , Sandeep Kumar , Zhiwu Wang , Yi Zheng","doi":"10.1016/j.watres.2025.123604","DOIUrl":"10.1016/j.watres.2025.123604","url":null,"abstract":"<div><div>Aerobic fermentation is a simple and environmentally friendly method to treat and recover nutrients from hydrothermal liquefaction aqueous phase (HTLAP). This study evaluated the chemical composition and aerobic biodegradability of HTLAP derived from corn stover under different hydrothermal liquefaction (HTL) conditions. The compositions of HTLAP followed specific patterns corresponding to HTL reaction severity, with high severity leading to increased concentrations of certain phenolic compounds. The elevated phenolics contributed to stronger inhibition of HTLAP on <em>Aspergillus niger</em> and <em>Rhodococcus jostii</em>. The half-maximal inhibitory concentration (IC<sub>50</sub>) of HTLAP for both microbes can be well predicted by linear regression models with HTL reaction temperature and time as the input variables, while corn stover solid loading showed no significant effect on IC<sub>50</sub> and was not included in the models. Furthermore, aerobic fermentation with <em>A. niger</em> followed by <em>R. jostii</em> was demonstrated to be a versatile treatment process for corn stover HTLAP derived from a broad range of HTL conditions, achieving 45–70 % of COD removal. This research provides a quantitative understanding of the relationships between HTL reaction conditions, HTLAP composition, and aerobic biodegradability via <em>A. niger</em> and <em>R. jostii</em>, laying the foundation for integrating HTLAP aerobic fermentation into the HTL system, potentially enhancing its overall cost-efficiency and sustainability.</div></div>","PeriodicalId":443,"journal":{"name":"Water Research","volume":"281 ","pages":"Article 123604"},"PeriodicalIF":11.4,"publicationDate":"2025-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143784722","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 : 2025-04-05DOI: 10.1016/j.watres.2025.123529
Rui Zhang, Sixin Zhang, Chunrui Li, Bin Cui, Dandan Zhou
Polyvinyl alcohol (PVA) wastewater is characterized by low biochemistry and poor biodegradability. Transboundary intercellular communication between fungi and bacteria modulates microbial metabolism activity. This mechanism facilitates the biological treatment of PVA wastewater potentially. In this study, a Geotrichum candidume enhanced activated sludge system was developed to treat PVA wastewater. The transboundary intercellular communication mechanism among fungi and bacteria was elucidated, and the promotion of PVA removal was studied. Results showed that G. geotrichum sensed the N-decanoyl-l-homoserine lactone (C10-HSL) secreted by Acidovorax, leading to the upregulation of functional genes (HAO, LACC1, FAHD) for PVA degradation. Dehydrogenase (DHA) and laccase activities were increased by 15.2 %-38.6 % and 77.1 %-114.5 % after C10-HSL addition. Meanwhile, C10-HSL enhanced metabolic processes such as tricarboxylic acid cycle (TCA cycle), and oxidative phosphorylation in G. geotrichum to accelerate PVA degradation. As a result, G. geotrichum biodegraded PVA into aldehydes and ketones, which were further mineralized by bacteria such as Dechloromonas. For the co-culture system, the synergistic interaction between G. geotrichum and functional bacteria significantly enhanced PVA degradation via the intercellular communication process. The PVA and chemical oxygen demand (COD) removal increased by 31.7 % and 28.3 %, respectively, compared to the activated sludge system. This study offers a novel theoretical foundation and approach for the biological treatment of PVA wastewater through fungal-bacterial transboundary intercellular communication.
{"title":"Transboundary intercellular communication mechanisms in the treatment of polyvinyl alcohol (PVA) wastewater by Geotrichum candidume enhanced activated sludge","authors":"Rui Zhang, Sixin Zhang, Chunrui Li, Bin Cui, Dandan Zhou","doi":"10.1016/j.watres.2025.123529","DOIUrl":"10.1016/j.watres.2025.123529","url":null,"abstract":"<div><div>Polyvinyl alcohol (PVA) wastewater is characterized by low biochemistry and poor biodegradability. Transboundary intercellular communication between fungi and bacteria modulates microbial metabolism activity. This mechanism facilitates the biological treatment of PVA wastewater potentially. In this study, a <em>Geotrichum candidume</em> enhanced activated sludge system was developed to treat PVA wastewater. The transboundary intercellular communication mechanism among fungi and bacteria was elucidated, and the promotion of PVA removal was studied. Results showed that <em>G. geotrichum</em> sensed the N-decanoyl-<span>l</span>-homoserine lactone (C10-HSL) secreted by <em>Acidovorax</em>, leading to the upregulation of functional genes (<em>HAO, LACC1, FAHD</em>) for PVA degradation. Dehydrogenase (DHA) and laccase activities were increased by 15.2 %-38.6 % and 77.1 %-114.5 % after C10-HSL addition. Meanwhile, C10-HSL enhanced metabolic processes such as tricarboxylic acid cycle (TCA cycle), and oxidative phosphorylation in <em>G. geotrichum</em> to accelerate PVA degradation. As a result, <em>G. geotrichum</em> biodegraded PVA into aldehydes and ketones, which were further mineralized by bacteria such as <em>Dechloromonas</em>. For the co-culture system, the synergistic interaction between <em>G. geotrichum</em> and functional bacteria significantly enhanced PVA degradation via the intercellular communication process. The PVA and chemical oxygen demand (COD) removal increased by 31.7 % and 28.3 %, respectively, compared to the activated sludge system. This study offers a novel theoretical foundation and approach for the biological treatment of PVA wastewater through fungal-bacterial transboundary intercellular communication.</div></div>","PeriodicalId":443,"journal":{"name":"Water Research","volume":"281 ","pages":"Article 123529"},"PeriodicalIF":11.4,"publicationDate":"2025-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143777113","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 : 2025-04-05DOI: 10.1016/j.watres.2025.123602
Rui Gao , Shu-Hong Gao , Jun Li , Fang Huang , Yanmei Zhao , Jingni Xie , Yusheng Pan , Wanying Zhang , Aijie Wang
Disinfection residual bacteria (DRB) are widely present in the reclaimed treatment effluents and can regrow during the downstream distribution and storage, posing a threat to the biosafety of reuse applications. Recently, far ultraviolet (UV222) have garnered augmented attention due to the highly efficient and energy-intensive oxidation, making them a potential approach for the deep inactivation of DRB. However, there remains a lack of quantitative analyses on how to monitor the disinfection intensity to mitigate the health risks associated with DRB. In this study, we used the UV222, UV222/H₂O₂ and UV222/peroxymonosulfate (PMS) systems to treat model DRB including Escherichia coli, Pseudomonas aeruginosa, and Bacillus subtilis, and developed a multiparameter model to accurately present the dose-culturability relationship. On this basis, we conducted the simulated disinfection, and detected the viability status and regrowth potential of DRB during the post-disinfection processes. It turned out that UV222 alone exhibited the superiority over UV254, especially for treating Pseudomonas aeruginosa. UV222/H2O2 and UV222/PMS systems further improved the inactivation rates. The practical UV doses for full-scale reclaimed disinfection (10–200 mJ/cm²) were sufficient for the UV222-based systems to inactivate DRB (initial 107 CFU/mL) to the safe level in effluent measured by culture methods. But substantial DRB still persisted in VBNC state, which necessitated higher doses of 200–450 mJ/cm2 to further inhibit the regrowth under accidental contamination and prolonged transport/storage culture. Fortunately, H2O2 provided residual disinfection for Bacillus subtilis, and PMS performed promising sustained disinfection for all the three DRB. This study provided valuable insights for the expanded application of UV222 disinfection and future updates of pathogen standards in reclaimed water treatment.
{"title":"Removal of disinfection residual bacteria in UV222, UV222/H2O2 and UV222/peroxymonosulfate systems: what is the safe usage for wastewater reclamation","authors":"Rui Gao , Shu-Hong Gao , Jun Li , Fang Huang , Yanmei Zhao , Jingni Xie , Yusheng Pan , Wanying Zhang , Aijie Wang","doi":"10.1016/j.watres.2025.123602","DOIUrl":"10.1016/j.watres.2025.123602","url":null,"abstract":"<div><div>Disinfection residual bacteria (DRB) are widely present in the reclaimed treatment effluents and can regrow during the downstream distribution and storage, posing a threat to the biosafety of reuse applications. Recently, far ultraviolet (UV<sub>222</sub>) have garnered augmented attention due to the highly efficient and energy-intensive oxidation, making them a potential approach for the deep inactivation of DRB. However, there remains a lack of quantitative analyses on how to monitor the disinfection intensity to mitigate the health risks associated with DRB. In this study, we used the UV<sub>222</sub>, UV<sub>222</sub>/H₂O₂ and UV<sub>222</sub>/peroxymonosulfate (PMS) systems to treat model DRB including <em>Escherichia coli, Pseudomonas aeruginosa</em>, and <em>Bacillus subtilis</em>, and developed a multiparameter model to accurately present the dose-culturability relationship. On this basis, we conducted the simulated disinfection, and detected the viability status and regrowth potential of DRB during the post-disinfection processes. It turned out that UV<sub>222</sub> alone exhibited the superiority over UV<sub>254</sub>, especially for treating <em>Pseudomonas aeruginosa</em>. UV<sub>222</sub>/H<sub>2</sub>O<sub>2</sub> and UV<sub>222</sub>/PMS systems further improved the inactivation rates. The practical UV doses for full-scale reclaimed disinfection (10–200 mJ/cm²) were sufficient for the UV<sub>222</sub>-based systems to inactivate DRB (initial 10<sup>7</sup> CFU/mL) to the safe level in effluent measured by culture methods. But substantial DRB still persisted in VBNC state, which necessitated higher doses of 200–450 mJ/cm<sup>2</sup> to further inhibit the regrowth under accidental contamination and prolonged transport/storage culture. Fortunately, H<sub>2</sub>O<sub>2</sub> provided residual disinfection for <em>Bacillus subtilis</em>, and PMS performed promising sustained disinfection for all the three DRB. This study provided valuable insights for the expanded application of UV<sub>222</sub> disinfection and future updates of pathogen standards in reclaimed water treatment.</div></div>","PeriodicalId":443,"journal":{"name":"Water Research","volume":"282 ","pages":"Article 123602"},"PeriodicalIF":11.4,"publicationDate":"2025-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143782930","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 : 2025-04-05DOI: 10.1016/j.watres.2025.123603
Margaret E. Knight, Kata Farkas, Adriana Kiss, Davey L. Jones
The circulation of antimicrobial resistance (AMR) bacteria between human populations and the environment is a key driver of the global AMR burden, with wastewater acting as a major route of transmission. In this nationwide study, influent and effluent samples were collected from 47 municipal wastewater treatment plants (WWTPs) across Wales, covering areas of varying sociodemographics and representing approximately 66% of the population connected to the main sewer network. Additionally, 76 river and estuarine sediment samples were collected upstream and downstream of the WWTPs, as well as from nearby recreational beaches. High-throughput qPCR was used to quantify 76 antimicrobial resistance genes (ARGs), 10 mobile genetic elements and 5 pathogens. Our analyses revealed that the absolute abundance and composition of the influent resistome was influenced by increasing WWTP catchment population size and density. Significant shifts in the resistome were observed following the wastewater treatment process, with the biological treatment stage identified as a critical determinant of AMR removal efficiency. WWTPs using biological filter beds were found to be more effective in reducing ARG relative abundances compared to those employing activated sludge processes. Despite the presence of ARGs in the effluent, the abundance and diversity of the river sediment resistomes did not increase downstream of the WWTPs. However, the presence of a resistome was found in all sediment samples, with varying compositions influenced by WWTP size and sediment source. Altogether, these findings highlight the complex and interconnected factors that shape the resistome across the wastewater-environment continuum, highlighting the need for comprehensive, nationwide surveillance studies to inform targeted interventions and mitigate the spread of AMR.
抗菌药耐药性 (AMR) 细菌在人类和环境之间的传播是造成全球 AMR 负担的主要原因，而废水则是主要的传播途径。在这项全国性研究中，我们从威尔士的 47 家市政污水处理厂 (WWTP) 采集了进水和出水样本，这些污水处理厂覆盖了不同社会人口分布的地区，约占接入主污水管网人口的 66%。此外，还在污水处理厂的上游和下游以及附近的休闲海滩收集了 76 份河流和河口沉积物样本。我们使用高通量 qPCR 对 76 个抗菌药耐药性基因 (ARG)、10 个移动遗传因子和 5 种病原体进行了定量分析。我们的分析表明，进水抗药性基因组的绝对丰度和组成受污水处理厂集水区人口规模和密度增加的影响。在废水处理过程中，我们观察到抗药性组发生了显著变化，生物处理阶段被认为是决定 AMR 去除效率的关键因素。与采用活性污泥法的污水处理厂相比，采用生物滤床的污水处理厂能更有效地降低 ARG 的相对丰度。尽管污水中存在 ARGs，但在污水处理厂下游，河流沉积物抗性体的丰度和多样性并未增加。不过，在所有沉积物样本中都发现了抗性组，其组成受污水处理厂规模和沉积物来源的影响而各不相同。总之，这些发现凸显了在废水-环境连续体中形成抗药性组的复杂而相互关联的因素，强调了进行全面的全国性监测研究的必要性，以便为有针对性的干预措施提供信息，并减缓 AMR 的传播。
{"title":"National-Scale Insights into AMR Transmission Along the Wastewater-Environment Continuum","authors":"Margaret E. Knight, Kata Farkas, Adriana Kiss, Davey L. Jones","doi":"10.1016/j.watres.2025.123603","DOIUrl":"https://doi.org/10.1016/j.watres.2025.123603","url":null,"abstract":"The circulation of antimicrobial resistance (AMR) bacteria between human populations and the environment is a key driver of the global AMR burden, with wastewater acting as a major route of transmission. In this nationwide study, influent and effluent samples were collected from 47 municipal wastewater treatment plants (WWTPs) across Wales, covering areas of varying sociodemographics and representing approximately 66% of the population connected to the main sewer network. Additionally, 76 river and estuarine sediment samples were collected upstream and downstream of the WWTPs, as well as from nearby recreational beaches. High-throughput qPCR was used to quantify 76 antimicrobial resistance genes (ARGs), 10 mobile genetic elements and 5 pathogens. Our analyses revealed that the absolute abundance and composition of the influent resistome was influenced by increasing WWTP catchment population size and density. Significant shifts in the resistome were observed following the wastewater treatment process, with the biological treatment stage identified as a critical determinant of AMR removal efficiency. WWTPs using biological filter beds were found to be more effective in reducing ARG relative abundances compared to those employing activated sludge processes. Despite the presence of ARGs in the effluent, the abundance and diversity of the river sediment resistomes did not increase downstream of the WWTPs. However, the presence of a resistome was found in all sediment samples, with varying compositions influenced by WWTP size and sediment source. Altogether, these findings highlight the complex and interconnected factors that shape the resistome across the wastewater-environment continuum, highlighting the need for comprehensive, nationwide surveillance studies to inform targeted interventions and mitigate the spread of AMR.","PeriodicalId":443,"journal":{"name":"Water Research","volume":"40 3 1","pages":""},"PeriodicalIF":12.8,"publicationDate":"2025-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143782931","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 : 2025-04-05DOI: 10.1016/j.watres.2025.123601
Tyler A. Malkoske, Pierre R. Bérubé, Robert C. Andrews
Microplastics (MPs) are ubiquitous in global drinking water sources (lakes, rivers), with reported concentrations ranging from 0.5 to >7,500 particles/L. Ultrafiltration (UF), widely applied in drinking water treatment, is anticipated to represent an effective barrier to MPs due to its pore size (0.01-0.1 µm), which can retain MPs of potential health concern. To-date limited studies have reported that MPs may contribute to UF fouling, albeit when considering concentrations up to 10 orders of magnitude higher than those typically observed in source waters. The present study evaluated the retention of MPs by UF membranes when incorporating coagulation/flocculation pre-treatment, as well as their release during hydraulic and chemical cleaning. Polyethylene (PE) fragments, representing a range of environmentally relevant sizes (1-50 µm) and concentrations (907±293 particles/L), were spiked into untreated lake waters prior to coagulation/flocculation-UF. Results suggest that in the absence of coagulant (alum) addition, only 50% of MPs retained during UF permeation were subsequently released during hydraulic cleaning. The release of MPs during hydraulic cleaning decreased (<20%) at medium and high (8 mg/L, 15 mg/L) alum dosages when compared to the absence of coagulant addition. Chemical cleaning with sodium hypochlorite (500 mg/L) was only capable of releasing 20% to 60% of retained MPs. Both hydraulic and chemical cleaning were less effective for the release of MPs when compared to reversible fouling resistance, organic matter, and aluminum. As such, future research is required to determine if the accumulation of MPs leads to increased UF fouling over extended operating periods, in addition cleaning practices which specifically target MPs should be further examined. Low and medium alum dosages (2 mg/L, 8 mg/L) were observed to increase the release of retained MPs during chemical cleaning, suggesting that incorporation of coagulation pre-treatment is useful to increase the release of MPs and minimize potential long-term accumulation on membranes.
{"title":"Hydraulic and chemical cleaning efficiency for the release of microplastics retained during coagulation/flocculation-ultrafiltration","authors":"Tyler A. Malkoske, Pierre R. Bérubé, Robert C. Andrews","doi":"10.1016/j.watres.2025.123601","DOIUrl":"https://doi.org/10.1016/j.watres.2025.123601","url":null,"abstract":"Microplastics (MPs) are ubiquitous in global drinking water sources (lakes, rivers), with reported concentrations ranging from 0.5 to >7,500 particles/L. Ultrafiltration (UF), widely applied in drinking water treatment, is anticipated to represent an effective barrier to MPs due to its pore size (0.01-0.1 µm), which can retain MPs of potential health concern. To-date limited studies have reported that MPs may contribute to UF fouling, albeit when considering concentrations up to 10 orders of magnitude higher than those typically observed in source waters. The present study evaluated the retention of MPs by UF membranes when incorporating coagulation/flocculation pre-treatment, as well as their release during hydraulic and chemical cleaning. Polyethylene (PE) fragments, representing a range of environmentally relevant sizes (1-50 µm) and concentrations (907±293 particles/L), were spiked into untreated lake waters prior to coagulation/flocculation-UF. Results suggest that in the absence of coagulant (alum) addition, only 50% of MPs retained during UF permeation were subsequently released during hydraulic cleaning. The release of MPs during hydraulic cleaning decreased (<20%) at medium and high (8 mg/L, 15 mg/L) alum dosages when compared to the absence of coagulant addition. Chemical cleaning with sodium hypochlorite (500 mg/L) was only capable of releasing 20% to 60% of retained MPs. Both hydraulic and chemical cleaning were less effective for the release of MPs when compared to reversible fouling resistance, organic matter, and aluminum. As such, future research is required to determine if the accumulation of MPs leads to increased UF fouling over extended operating periods, in addition cleaning practices which specifically target MPs should be further examined. Low and medium alum dosages (2 mg/L, 8 mg/L) were observed to increase the release of retained MPs during chemical cleaning, suggesting that incorporation of coagulation pre-treatment is useful to increase the release of MPs and minimize potential long-term accumulation on membranes.","PeriodicalId":443,"journal":{"name":"Water Research","volume":"6 1","pages":""},"PeriodicalIF":12.8,"publicationDate":"2025-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143784724","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 : 2025-04-05DOI: 10.1016/j.watres.2025.123599
Jun Li , Lili Li , Weiqiang Liang , Lingyu Li , Ruya Wang , Zhenhua Wang , Chunxia Ma
Most studies on the biological effects of exogenous pollutants have focused on whole samples or cell populations, and lack spatial heterogeneity consideration due to technical limitations. Microcystin-LR (MC-LR) from cyanobacterial blooms threatens ecosystems and human health, while microcystin-LR disinfection by-products (MCLR-DBPs) in drinking water remain a concern for their toxin-like structure. This study introduces spatial multi-omics to investigate the disruptions caused by ingestion of MC-LR and MCLR-DBPs in zebrafish. The method integrates metabolomics, spatial metabolomics, and spatial transcriptomics to characterize the overall metabolic changes in whole zebrafish caused by MC-LR and MCLR-DBPs, then provides further insight into the variation of spatial distribution of metabolites and genes in MC-LR and MCLR-DBPs targeted organ. The results showed that MC-LR and MCLR-DBPs induced oxidative stress and metabolic imbalance, and disrupted the physiological homeostasis of zebrafish. Spatial multi-omics analysis further revealed that MC-LR and MCLR-DBPs exacerbate disruptions in energy and lipid metabolism, methylation processes, and immune pathways by modulating the expression of genes such as gatm, gnmt, cyp2p9, and tdo2b. In conclusion, this study developed a spatial multi-omics approach that not only enhances the understanding of the biological effects of MC-LR and MCLR-DBPs but also provides robust technical support for investigating other environmental pollutants.
{"title":"Spatial multi-omics analysis of metabolic heterogeneity in zebrafish exposed to microcystin-LR and its disinfection byproducts","authors":"Jun Li , Lili Li , Weiqiang Liang , Lingyu Li , Ruya Wang , Zhenhua Wang , Chunxia Ma","doi":"10.1016/j.watres.2025.123599","DOIUrl":"10.1016/j.watres.2025.123599","url":null,"abstract":"<div><div>Most studies on the biological effects of exogenous pollutants have focused on whole samples or cell populations, and lack spatial heterogeneity consideration due to technical limitations. Microcystin-LR (MC-LR) from cyanobacterial blooms threatens ecosystems and human health, while microcystin-LR disinfection by-products (MCLR-DBPs) in drinking water remain a concern for their toxin-like structure. This study introduces spatial multi-omics to investigate the disruptions caused by ingestion of MC-LR and MCLR-DBPs in zebrafish. The method integrates metabolomics, spatial metabolomics, and spatial transcriptomics to characterize the overall metabolic changes in whole zebrafish caused by MC-LR and MCLR-DBPs, then provides further insight into the variation of spatial distribution of metabolites and genes in MC-LR and MCLR-DBPs targeted organ. The results showed that MC-LR and MCLR-DBPs induced oxidative stress and metabolic imbalance, and disrupted the physiological homeostasis of zebrafish. Spatial multi-omics analysis further revealed that MC-LR and MCLR-DBPs exacerbate disruptions in energy and lipid metabolism, methylation processes, and immune pathways by modulating the expression of genes such as <em>gatm, gnmt, cyp2p9</em>, and <em>tdo2b</em>. In conclusion, this study developed a spatial multi-omics approach that not only enhances the understanding of the biological effects of MC-LR and MCLR-DBPs but also provides robust technical support for investigating other environmental pollutants.</div></div>","PeriodicalId":443,"journal":{"name":"Water Research","volume":"280 ","pages":"Article 123599"},"PeriodicalIF":11.4,"publicationDate":"2025-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143782929","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 : 2025-04-04DOI: 10.1016/j.watres.2025.123534
Mingqi Guo, Stefan A.F. Bon, Soroush Abolfathi
Despite the significance of rivers and streams in transporting terrestrial microplastics (MP) to the oceans, limited research has focused on the role of aquatic vegetation and their complex geometry in shaping the underlying mechanisms governing MP mixing and dispersion processes in riverine environments. This study, for the first time, investigates the transport and fate of non-buoyant MPs, specifically those with diameters of 188 nm and and a density of 1.04 g/cm, in floating Eichhornia crassipes canopies under flow conditions typical of natural rivers (0.0167-0.0667 m/s). Physical modelling tests reveal that aquatic vegetation significantly alters the hydrodynamic structure and enhances the dissipation of turbulence in the water column, leading to decreased velocities, diversified length scales, and increased turbulent kinetic energy (TKE) in regions with higher frontal vegetation areas. This turbulence, in turn, facilitated momentum exchange and vertical mixing, particularly in regions with the most pronounced frontal area changes. Wider canopy spacing promoted the evolution of wake turbulence and facilitated wake expansion throughout the water column, generating coherent structures that effectively doubled the integral length scales with increasing distance between canopies from 0.5 m to 1.5 m. This adjustment resulted in a more uniformly dispersed downstream movement of MPs. Notably, the presence of canopies amplified MP diffusivity by 10-40 times compared to equivalent unvegetated conditions, transitioning the primary mixing mechanism from shear-induced velocity gradients to turbulence enhanced by plant-flow interactions. This study offers a robust framework for quantifying MP mixing and predicting longitudinal dispersion coefficients within the floating vegetated flows, by developing models that depict the vertical profiles of TKE and turbulent diffusivity featured by canopy morphology and spacing. The insights from this study make a significant contribution toward improving our ability to predict the mixing and fate of MPs in riverine environments and underscore the necessity of incorporating the complex dynamics of aquatic vegetation into environmental management and MP risk assessments.
{"title":"Transport dynamics of microplastics within aquatic vegetation featuring realistic plant morphology","authors":"Mingqi Guo, Stefan A.F. Bon, Soroush Abolfathi","doi":"10.1016/j.watres.2025.123534","DOIUrl":"https://doi.org/10.1016/j.watres.2025.123534","url":null,"abstract":"Despite the significance of rivers and streams in transporting terrestrial microplastics (MP) to the oceans, limited research has focused on the role of aquatic vegetation and their complex geometry in shaping the underlying mechanisms governing MP mixing and dispersion processes in riverine environments. This study, for the first time, investigates the transport and fate of non-buoyant MPs, specifically those with diameters of 188 nm and <span><math><mrow is=\"true\"><mn is=\"true\">6</mn><mspace is=\"true\" width=\"1em\"></mspace><mi is=\"true\" mathvariant=\"normal\">μ</mi><mi is=\"true\" mathvariant=\"normal\">m</mi></mrow></math></span> and a density of 1.04 g/cm<span><math><msup is=\"true\"><mrow is=\"true\"></mrow><mrow is=\"true\"><mn is=\"true\">3</mn></mrow></msup></math></span>, in floating <em>Eichhornia crassipes</em> canopies under flow conditions typical of natural rivers (0.0167-0.0667 m/s). Physical modelling tests reveal that aquatic vegetation significantly alters the hydrodynamic structure and enhances the dissipation of turbulence in the water column, leading to decreased velocities, diversified length scales, and increased turbulent kinetic energy (TKE) in regions with higher frontal vegetation areas. This turbulence, in turn, facilitated momentum exchange and vertical mixing, particularly in regions with the most pronounced frontal area changes. Wider canopy spacing promoted the evolution of wake turbulence and facilitated wake expansion throughout the water column, generating coherent structures that effectively doubled the integral length scales with increasing distance between canopies from 0.5 m to 1.5 m. This adjustment resulted in a more uniformly dispersed downstream movement of MPs. Notably, the presence of canopies amplified MP diffusivity by 10-40 times compared to equivalent unvegetated conditions, transitioning the primary mixing mechanism from shear-induced velocity gradients to turbulence enhanced by plant-flow interactions. This study offers a robust framework for quantifying MP mixing and predicting longitudinal dispersion coefficients within the floating vegetated flows, by developing models that depict the vertical profiles of TKE and turbulent diffusivity featured by canopy morphology and spacing. The insights from this study make a significant contribution toward improving our ability to predict the mixing and fate of MPs in riverine environments and underscore the necessity of incorporating the complex dynamics of aquatic vegetation into environmental management and MP risk assessments.","PeriodicalId":443,"journal":{"name":"Water Research","volume":"37 1","pages":""},"PeriodicalIF":12.8,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143782876","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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