Environmental Science: Water Research & Technology最新文献

{"title":"Mechanism by which micro-nano bubbles impact biofilm growth in drinking water distribution systems†","authors":"Aibao Luo, Tianzhi Wang, Peiyuan Luo, Zhiwei Zheng, Manuel Fiallos, Yongning Bian and Soon-Thiam Khu","doi":"10.1039/D4EW00704B","DOIUrl":"https://doi.org/10.1039/D4EW00704B","url":null,"abstract":"<p >Biofilm growth in drinking water distribution systems (DWDS) has become a concern due to the various water quality issues it causes, and thus suitable disinfection methods are required to ensure drinking water safety. Micro-nano bubbles (MNBs) technology provides a possible breakthrough in dealing with the above issues. This paper simulates the hydraulic conditions of the terminal pipeline in a DWDS to explore biofilm formation under the influence of MNBs from different gas sources. To further understand the changes in water quality, this study evaluated the biofilm morphology, composition, microbial communities, and water quality at different experiment stages. Therefore, we divide the biofilm formation into three phases: the slow growth phase (0–27 days) (SP), rapid growth phase (27–42 days) (RP), and dynamic stability phase (42–66 days) (DP). Biofilm formation was significantly inhibited in the slow growth and rapid growth phases, especially after combining the MNBs with oxygen, causing a reduction in biofilm dry weight of 77.87%. The mechanism by which the MNBs regulate biofilm growth is different at each stage. During the SP stage, physical obstruction and chemical oxidation occurs, at the RP stage oxidative inactivation takes place, whilst at the DP stage adsorption and scour predominate. Notably, the MNBs first attach to the tank's inner surface, forming a hydrophobic layer to increase the difficulty of microbe adherence. Then, an extensive amount of hydroxyl radicals (˙OH) were generated by the MNBs collapsing, reducing the number of bacteria present while increasing the competitive advantage of oxidation-resistant bacteria. This disinfection method narrows the differences in number between the dominant bacterial populations in the biofilm, which changes the key strains and reduces microbial community diversity. As a result, the inactivation rate of <em>Planctomycetes</em> reached 54.22–61.66%, and a significant reduction of the organic matter in water was achieved (87.9% removal of TOC). These results proved that the MNBs have great potential in treating biofilms in DWDS and improving drinking water quality.</p>","PeriodicalId":75,"journal":{"name":"Environmental Science: Water Research & Technology","volume":" 3","pages":" 754-767"},"PeriodicalIF":3.5,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143513054","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Deciphering molecular composition and summarizing control strategies of unknown disinfection by-products in water and wastewater based on FT-ICR-MS analysis: a comprehensive review","authors":"Changmin Wang, Bingliang Zhang, Youzhuang Rong, Xifeng Shi and Yunyan Liu","doi":"10.1039/D4EW00889H","DOIUrl":"https://doi.org/10.1039/D4EW00889H","url":null,"abstract":"<p >Disinfection is crucial to inactivate pathogenic bacteria and prevent the spread of epidemic diseases during drinking water/wastewater treatment. However, adverse disinfection by-products (DBPs) are inevitably produced during the disinfection process. Previous reviews primarily paid attention to the occurrence, formation, and control of some known DBPs, whereas few studies focused on the relatively large proportion of unknown DBPs. This study provided an overall review of unknown DBPs in different water bodies. Firstly, the analytical method of unknown DBPs based on Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) analysis was described in detail. Secondly, the molecular composition and characteristics of unknown DBPs in various water bodies during different disinfection processes were systemically summarized. Moreover, the possible transformation reactions involved in forming unknown DBPs were thoroughly proposed. Thirdly, the control strategies (<em>e.g.</em>, pre-treatment, selection and optimization disinfection conditions, and post-treatment) of unknown DBPs were comprehensively listed. Finally, future studies should focus on identifying molecular structures, screening the highly toxic compounds, investigating the formation mechanisms, and developing more effective control strategies for unknown DBPs. Overall, this review will narrow the knowledge gap about the composition and control of unknown DBPs in different water bodies, thereby protecting human health and improving ecological safety.</p>","PeriodicalId":75,"journal":{"name":"Environmental Science: Water Research & Technology","volume":" 3","pages":" 573-589"},"PeriodicalIF":3.5,"publicationDate":"2025-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143513064","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fly ash integration for enhanced partial nitrification stabilization and aerobic granular sludge stability under low-temperature conditions†","authors":"Jun Li, Salma Tabassum and Hüseyin Altundag","doi":"10.1039/D4EW00947A","DOIUrl":"https://doi.org/10.1039/D4EW00947A","url":null,"abstract":"<p >Anaerobic ammonium oxidation requires the influent NO<small>₂</small><small>⁻</small>–N/NH<small>₄</small><small>⁺</small>–N ratio to be 1.32 : 1. At low temperatures, poor sludge settling performance, expansion, and loss are profound. The effluent water quality cannot meet the influent requirements of the anaerobic ammonium oxidation stage. In this study that was operated for more than 300 days, the SBR was used to inoculate flocculent sludge and cultivate it to form aerobic granular sludge (AGS), which was then domesticated into partially nitrosated granular sludge (PNGS), and gradually reduced to low-temperature for intensive cultivation. During the cooling process, the ratio of NO<small>₂</small><small>⁻</small>–N/NH<small>₄</small><small>⁺</small>–N in the effluent was maintained by controlling the aeration time and the operating cycle of the SBR to achieve the best partial nitrosation efficiency. PNGS cultured increased the volumetric load of NH<small>₄</small><small>⁺</small>–N removal from 0.24 kg (m<small>⁻³</small> d<small>⁻¹</small>) to 0.35 kg (m<small>⁻³</small> d<small>⁻¹</small>) at 15 °C compared with 30 °C. Fly ash was used as the crystal nucleus and carrier to prevent the disintegration of AGS at low temperatures (15 °C). The effect of fly ash dosages 50, 100, 150, 200, 250, 300 mg L<small>⁻¹</small> on partial nitrification efficiency was determined. It accelerates the formation of new AGS and improves partial nitrification performance. Compared with no fly ash addition at 15 °C, when fly ash dosage of 250 mg L<small>⁻¹</small> was added, the NO<small>₂</small><small>⁻</small>–N accumulation rate increased from 75% to 85%, and NH<small>₄</small><small>⁺</small>–N volume removal load increased from 0.35 kg (m<small>⁻³</small> d<small>⁻¹</small>) to 0.45 kg (m<small>⁻³</small> d<small>⁻¹</small>). Effluent NO<small>₂</small><small>⁻</small>–N/NH<small>₄</small><small>⁺</small>–N increased from 0.55 : 1 to 1.20 : 1. Effluent NO<small>₂</small><small>⁻</small>–N/NH<small>₄</small><small>⁺</small>–N meets anammox influent requirements. This study can be used to build sustainable wastewater treatment in low-temperature regions worldwide.</p>","PeriodicalId":75,"journal":{"name":"Environmental Science: Water Research & Technology","volume":" 3","pages":" 737-753"},"PeriodicalIF":3.5,"publicationDate":"2025-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143513053","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effective measuring campaigns for reliable and informative full-scale WWTP data†","authors":"Q. H. Le, P. Carrera, M. C. M. van Loosdrecht and E. I. P. Volcke","doi":"10.1039/D4EW00315B","DOIUrl":"https://doi.org/10.1039/D4EW00315B","url":null,"abstract":"<p >Sensor availability and costs are nowadays no longer limiting data gathering at wastewater treatment plants (WWTPs). However, one should be aware that a higher amount of measured data gathered does not necessarily imply that also more information is obtained. In this light, this contribution assesses the general applicability and the added value of a structured experimental design approach for planning measurement campaigns at WWTPs, in view of mass-balance-based data reconciliation. To this end, the results from full-scale WWTP case studies available in the literature were compared to those obtained with the developed structured experimental design procedure. Planning measurement campaigns comprises the selection of (additional) measurements to meet a pre-set main goal. The need for a structured experimental design procedure replacing past expert judgment approaches became clear from the fact that three out of five case studies available in the literature failed to meet the main goal and/or performed unnecessary additional measurements. Translating the main goal into specific key variables was found essential in this respect. The general applicability of the procedure was proven with three outcomes. First, the procedure, involving well-defined steps, could be applied to different WWTP layouts. Second, it ensured the fulfilment of various main goals. Third, it provided useful outcomes, <em>i.e.</em>, optimal measurement campaigns, which reduced the need for additional measurements (40–70% less) compared to expert knowledge approaches, hence more information could be obtained with less analytical data. Overall, the experimental design procedure proved a fast and useful tool ensuring the success of subsequent mass-balance-based data reconciliation.</p>","PeriodicalId":75,"journal":{"name":"Environmental Science: Water Research & Technology","volume":" 3","pages":" 667-680"},"PeriodicalIF":3.5,"publicationDate":"2025-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/ew/d4ew00315b?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143513071","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Guanidine-modified cellulose enhances capturing and recovery of phosphates from wastewater†","authors":"Gunanka Hazarika, Sribash Das, Anjali Patel and Debasis Manna","doi":"10.1039/D4EW00910J","DOIUrl":"https://doi.org/10.1039/D4EW00910J","url":null,"abstract":"<p >The recovery of dwindling materials from wastewater could be helpful in resolving the rising need for resources in society. Phosphate is a nutrient that all living organisms require, but a reduction in global phosphate rock deposits could severely impact human food security in the near future. To mitigate this problem, we developed a Zn(<small>II</small>) coordinated 1-aminoguanidine (ag) functionalized cellulose-based biopolymer. The chemical structure of the synthesized biopolymer was characterized using several analytical techniques, including Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FESEM), FESEM-energy dispersive X-ray spectroscopy (FESEM-EDX), and X-ray photoelectron spectroscopy (XPS). The phosphate binding to the polymer was investigated by FT-IR, FESEM–EDX, XPS and ion chromatography (IC) analyses. The IC analysis revealed strong and fast phosphate removal efficacy of the polymer, with a maximum adsorption capacity of 310 mg g<small>⁻¹</small> (pH 7.0). Interestingly, the sequestered phosphate could be readily retrieved, and the biopolymer could be easily recycled by changing the pH (∼13) of the aqueous solution. Further studies revealed that the presence of guanidinium moieties was essential for its exfoliation in aqueous media and antibacterial activity against both Gram-negative and Gram-positive bacteria. The present work will assist in improving the design of water-insoluble biopolymers that could efficiently extract and recover phosphate from wastewater, thus reducing the detrimental effect of water eutrophication.</p>","PeriodicalId":75,"journal":{"name":"Environmental Science: Water Research & Technology","volume":" 3","pages":" 691-701"},"PeriodicalIF":3.5,"publicationDate":"2025-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143513078","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ferrate–acetylacetonate system to promote the degradation of sulfadimethoxine in mariculture tailwater†","authors":"Hongwei Sun, Zheng Li, Qiankun Du, Hanzhang Li, Hua Su, Jiamin Lin, Yuyi Zheng, Kaicong Cai, Shuangcheng Jiang, Changqing Liu and Chunshan Wu","doi":"10.1039/D4EW00832D","DOIUrl":"https://doi.org/10.1039/D4EW00832D","url":null,"abstract":"<p >The antibiotic residue in mariculture tailwater is an urgent environmental problem that needs to be addressed, and the development of effective treatment technologies is one of the solutions. Ferrate (Fe(<small>VI</small>))–acetylacetone (AA) has great potential for the degradation of antibiotics in mariculture tailwater. This study found that Fe(<small>VI</small>)–AA degradation of sulfadimethoxine (SDM) showed good results. When [Fe(<small>VI</small>)]<small>₀</small> : [AA]<small>₀</small> = 8 : 1, the removal rate of SDM could reach 95.73% in 10 min, which is a 66.01% enhancement over the result of Fe(<small>VI</small>) alone. Under the actual mariculture tailwater conditions, Fe(<small>VI</small>)–AA still removed 77.9% of SDM in 10 min, which is still 36.4% higher than the degradation result of Fe(<small>VI</small>) alone, indicating that it has good potential for application. A series of quenching experiments showed that high-valent iron (Fe(<small>V</small>), Fe(<small>IV</small>)) was the main active substance in the degradation of SDM by Fe(<small>VI</small>)–AA. ECOSAR analysis showed that most of the by-products produced by Fe(<small>VI</small>)–AA degradation of SDM were at non-toxic and low-toxicity levels, proving that Fe(<small>VI</small>)–AA is a green and efficient water treatment technology.</p>","PeriodicalId":75,"journal":{"name":"Environmental Science: Water Research & Technology","volume":" 4","pages":" 891-902"},"PeriodicalIF":3.5,"publicationDate":"2025-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143716621","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Seasonal variation and risk assessment for the presence of pharmaceuticals in Brazilian urban rivers†","authors":"Miraldo Santa Rosa dos Santos, Cristiane Vidal, Vinicius Sarracini Santos, Ramon Domingues and Cassiana Carolina Montagner","doi":"10.1039/D4EW00828F","DOIUrl":"https://doi.org/10.1039/D4EW00828F","url":null,"abstract":"<p >The presence of pharmaceuticals in water bodies has become a growing concern due to their potential effects on aquatic life. These compounds enter the environment through various routes, including untreated wastewater, wastewater treatment plants, rainwater runoff, and improper disposal of drugs. Therefore, there has been increasing interest in monitoring the occurrence of pharmaceuticals in natural waters, demanding the development of analytical methods for their detection. In this work, a UHPLC-MS/MS method was developed and validated to quantify acetaminophen, caffeine, diclofenac, and sulfathiazole in a working range varying from 1 to 100 000 ng L<small>⁻¹</small>, in order to assess their occurrence and risk to aquatic life in rivers and creeks located in three southeastern Brazilian metropolitan areas and cities (São José do Rio Preto, Campinas and Belo Horizonte) with different levels of urbanization. Preto, Turvo and Atibaia Rivers and Anhumas, Arrudas, Onça, and Isidoro Creeks were sampled during the dry and wet seasons. The presence of acetaminophen (157–7449 ng L<small>⁻¹</small>), caffeine (60–122 520 ng L<small>⁻¹</small>), diclofenac (62–176 ng L<small>⁻¹</small>), and sulfathiazole (34–40 ng L<small>⁻¹</small>) was confirmed more than once in the samples. The frequency of detection was different for each compound, being higher in the rivers more impacted by urban areas. The risk to aquatic life based on the risk quotient, calculated using the most sensitive PNEC (predicted non-effect concentration) for freshwaters, indicated concern about the concentrations of caffeine and diclofenac in some of the samples analyzed.</p>","PeriodicalId":75,"journal":{"name":"Environmental Science: Water Research & Technology","volume":" 3","pages":" 681-690"},"PeriodicalIF":3.5,"publicationDate":"2025-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143513077","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Lithium recovery from U.S. oil and gas produced waters: resource quality and siting considerations†","authors":"Sheila Gerardo and Wen Song","doi":"10.1039/D4EW00422A","DOIUrl":"https://doi.org/10.1039/D4EW00422A","url":null,"abstract":"<p >To meet the growing demand for lithium sustainably, secondary resources must be explored. Among nontraditional resource alternatives, brines co-produced from oil and gas (O&amp;G) operations are of particular interest owing to their abundance and considerable lithium concentrations. Whereas previous work has highlighted potential O&amp;G brines of interest for lithium extraction, the criteria to distinguish optimal from suboptimal O&amp;G produced waters are still unclear. In the following, we provide perspectives on assessing the feasibility and challenges of produced waters from key U.S. formations as lithium resources based on their water chemistry, production rates, and geographic placement. Specifically, we clarify the impact of production rates on the estimated lithium resources and how it may aggrandize evaluations. We assess how key secondary cation concentrations and ratios complicate downstream separation, and evaluate the role of the geographic coexistence of lithium resources and lithium consumers (<em>i.e.</em>, the manufacturing sector). Among the U.S. O&amp;G formations evaluated herein, the Marcellus shale emerges as an attractive formation for lithium extraction, with an estimated annual lithium metal output of 930 metric tons and lower secondary cation concentrations. The potential feasibility of brines from the Marcellus formation is enabled by its reduced need for downstream separation and purification, as well as its proximity to major lithium end-user facilities (<em>i.e.</em>, battery manufacturers). Overall, we provide an initial set of criteria to help evaluate O&amp;G formations for their potential to serve as lithium resources and provide an assessment of the lithium resources in key U.S. O&amp;G plays.</p>","PeriodicalId":75,"journal":{"name":"Environmental Science: Water Research & Technology","volume":" 3","pages":" 536-541"},"PeriodicalIF":3.5,"publicationDate":"2025-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/ew/d4ew00422a?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143513062","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Building-level wastewater surveillance as an early warning system for COVID-19 outbreaks in congregate living settings†","authors":"Natalie G. Exum, Steven J. Chow, Caroline Coulter, Christopher D. Gocke, Andrew Pekosz, Roanna Kessler and Kellogg J. Schwab","doi":"10.1039/D4EW00668B","DOIUrl":"https://doi.org/10.1039/D4EW00668B","url":null,"abstract":"<p >The COVID-19 pandemic presented an opportunity to collect wastewater (WW) from a defined population of individuals within a building and monitor the sewage for viral RNA as a leading indicator of COVID-19 infections. The evaluation of the effectiveness of building-level WW surveillance programs as an early warning system has been limited by a lack of frequent asymptomatic surveillance of the defined residential population under WW surveillance. In this study we present the epidemiologic diagnostics of WW surveillance (sensitivity (Se), specificity (Sp), positive predictive value (PPV) and negative predictive value (NPV)) from university residence halls. WW surveillance was layered on top of a rigorous asymptomatic testing program (three times per week) and serves as the gold standard for comparison. This study also spanned across both the Spring 2021 semester when students were unvaccinated and the Fall 2021 semester when &gt;95% of students were vaccinated for COVID-19 to understand how increased immunity may affect viral detection in WW. We analyzed composite WW samples from nine residential buildings that were collected twice weekly. The overall positive WW sample detection rate was 5.5% indicating the low-incidence context of this study population to allow for evaluation of WW surveillance as an early warning system. WW surveillance showed the best performance as a leading indicator of an infected individual when compared in a time inclusive of 1–2 days prior to the date of a clinical positive. The building-level WW surveillance sensitivity and specificity was found to be 60% and 94.9% (PPV: 47.4%; NPV: 96.9%), respectively in the Spring 2021; in the Fall 2021 sensitivity was reduced to 6.3% and specificity remained at a similar level of 97.5% (PPV: 14.3%; NPV: 94.1%). Combined for both semesters, the overall sensitivity and specificity were 32.3% and 96.4% (PPV: 38.5%; NPV: 95.3%). Convalescent shedding may explain up to 31% of false positive WW samples, contributing to decreased surveillance performance. This study demonstrates the greater effectiveness of building-level WW surveillance as an early warning system at the beginning of the COVID-19 pandemic when population-level immunity was naïve and fecal shedding of SARS-CoV-2 was likely more prevalent.</p>","PeriodicalId":75,"journal":{"name":"Environmental Science: Water Research & Technology","volume":" 3","pages":" 604-617"},"PeriodicalIF":3.5,"publicationDate":"2025-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143513066","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Removal of antibiotic resistance genes and co-selectors in a full-scale sewage treatment plant during droughts and floods†","authors":"Sourabh Dixit, Jayavignesh Vijayan, Harshita Singh, Indumathi M. Nambi, T. Renganathan, R. Ravikrishna and Gargi Singh","doi":"10.1039/D4EW00875H","DOIUrl":"https://doi.org/10.1039/D4EW00875H","url":null,"abstract":"<p >We investigated the effect of droughts and floods on the removal of antibiotic resistance genes and co-selectors in a 60 MLD sewage treatment plant (STP) in Perungudi town, Chennai city. Samples were collected once a month for 13 months and analysed for 7 antibiotic resistance genes (<em>sul</em>1, <em>erm</em>F, <em>tet</em>W, <em>mcr</em>5, <em>sul</em>2, <em>par</em>C, and <em>bla</em><small>_OXA-1</small>), the most used antibiotic in the region (ciprofloxacin), a non-pharmaceutical antibiotic (triclosan), and 3 co-selective heavy metals (copper, chromium, and lead). It was found that the total bacterial count decreased significantly in the STP (<em>p</em>-value = 0.03, Wilcoxon rank sum test), but the relative abundance of ARGs was not reduced in the STP. In fact, the relative abundances of <em>tet</em>W and <em>bla</em><small>_OXA-1</small> increased in the maturation pond and were higher in the effluent than in the influent (<em>p</em>-value = 0.03, Wilcoxon rank sum test). On the other hand, the relative abundances of most ARGs were reduced significantly in the anaerobic digester (<em>p</em>-value &lt; 0.05, Wilcoxon rank sum test). Overall relative abundances of <em>mcr</em>5, <em>tet</em>W, <em>erm</em>F, <em>int</em>I1, and <em>sul</em>2 in the raw sewage were higher in the dry summer than in the monsoon. The relative abundance of <em>int</em>I1 was correlated (Spearman correlation) with the relative abundances of <em>mcr</em>5 (<em>ρ</em> = 0.54), <em>erm</em>F (<em>ρ</em> = 0.52), and <em>tet</em>W (<em>ρ</em> = 0.61). Except for chromium, all the other targeted co-selectors were significantly removed from the STP throughout the year (<em>p</em> &gt; 0.05, Wilcoxon rank sum test). Overall, the targeted ARGs were not removed in the STP, and this underperformance was unaffected by periods of droughts and floods.</p>","PeriodicalId":75,"journal":{"name":"Environmental Science: Water Research & Technology","volume":" 3","pages":" 702-713"},"PeriodicalIF":3.5,"publicationDate":"2025-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143513050","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}