Pub Date : 2024-07-12DOI: 10.1038/s41545-024-00361-2
Jie Hu, Ran Yin, Jinfeng Wang, Hongqiang Ren
While the anaerobic-anoxic-oxic (AAO) process is the most widely applied biological wastewater treatment process in municipal wastewater treatment plants (WWTPs), it struggles to meet the increasing demands on biological toxicity control of the treated effluent. To tackle this challenge, this study develops machine learning (ML)-based models for optimizing the AAO treatment process towards improving its toxicity reduction efficacy for the effluent. The water quality parameters, treatment process parameters, and biological toxicity information (based on the nematode bioassay) of the effluent collected from 122 WWTPs in China are used to train the models. The validated models accurately predict the effluent’s quality parameters (average R2 = 0.81) and the biological toxicity reduction ratio of treatment process (R2 = 0.86). To further improve the toxicity reduction, we developed a multiple objective optimization framework to optimize the AAO process via unit process recombination. In the short-range unit combination, the toxicity reduction ratio of the four-unit combined processes (up to 79.8% of anaerobic-aerobic-anaerobic-aerobic) is significantly higher than others. After optimization, it helps to improve the average toxicity reduction efficacy of 122 WWTPs from 48.6% to 70.7%, with a maximum of 87.5%. The methodologies and findings derived from this work are expected to provide the foundation for the optimization, expansion, and technical transformation of biological wastewater treatment in WWTPs.
{"title":"Data driven multiple objective optimization of AAO process towards wastewater effluent biological toxicity reduction","authors":"Jie Hu, Ran Yin, Jinfeng Wang, Hongqiang Ren","doi":"10.1038/s41545-024-00361-2","DOIUrl":"10.1038/s41545-024-00361-2","url":null,"abstract":"While the anaerobic-anoxic-oxic (AAO) process is the most widely applied biological wastewater treatment process in municipal wastewater treatment plants (WWTPs), it struggles to meet the increasing demands on biological toxicity control of the treated effluent. To tackle this challenge, this study develops machine learning (ML)-based models for optimizing the AAO treatment process towards improving its toxicity reduction efficacy for the effluent. The water quality parameters, treatment process parameters, and biological toxicity information (based on the nematode bioassay) of the effluent collected from 122 WWTPs in China are used to train the models. The validated models accurately predict the effluent’s quality parameters (average R2 = 0.81) and the biological toxicity reduction ratio of treatment process (R2 = 0.86). To further improve the toxicity reduction, we developed a multiple objective optimization framework to optimize the AAO process via unit process recombination. In the short-range unit combination, the toxicity reduction ratio of the four-unit combined processes (up to 79.8% of anaerobic-aerobic-anaerobic-aerobic) is significantly higher than others. After optimization, it helps to improve the average toxicity reduction efficacy of 122 WWTPs from 48.6% to 70.7%, with a maximum of 87.5%. The methodologies and findings derived from this work are expected to provide the foundation for the optimization, expansion, and technical transformation of biological wastewater treatment in WWTPs.","PeriodicalId":19375,"journal":{"name":"npj Clean Water","volume":null,"pages":null},"PeriodicalIF":10.4,"publicationDate":"2024-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41545-024-00361-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141597382","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-11DOI: 10.1038/s41545-024-00354-1
Jinshan Zhao, Xiaolin Zhou, Chunzhen Fan, Zhiquan Wang, Zhan Jin, Ke Bei, Xiangyong Zheng, Min Zhao, Suqing Wu
Vallisneria spinulosa Yan (V.spinulosa Yan) with good ability of water purification is often used for ecological restoration of polluted water bodies. However, it is difficult to survive in turbid water bodies due to the low lighting condition. This study explored the feasibility of introducing artificial underwater light source into water bodies with high turbidity to strengthen the water restoration by V.spinulosa Yan. Addition of underwater light source promoted the clonal reproduction ability of V.spinulosa Yan, thus enhancing the removal loads of total nitrogen (TN), total phosphorus (TP), and nitrate nitrogen ( $${mathrm{NO}}^{-}_{3}{mbox{-}}{mathrm{N}}$$ ) by 1.60–3.43 × 10−2, 1.49–3.49 × 10−3, and 0.80–2.06 × 10−2 g m−2 d−1, respectively. Underwater light source significantly reduced the abundance of microbial community on V.spinulosa Yan leaves, as well as most nitrifying bacteria (Nitrosomonadaceae) and denitrifying bacteria (Nitrospira, Comamonadaceae, and Rhodocyclaceae) in the system. But the attachment of some Cyanophyta (Chloroplast and Cyanobacteria) and Photosynthetic bacteria (Rhodobacter) onto the leaves and the growth of Methyloligellaceae in water and sediments were promoted. Nitrogen and phosphorus removal by the growth system of V.spinulosa Yan without underwater light source mainly depended on the biological processes by functional bacteria, while the absorption and co-assimilation effect of V.spinulosa Yan with underwater light source.
{"title":"Underwater light source changes nitrogen and phosphorus removal pathways by Vallisneria spinulosa Yan growth system","authors":"Jinshan Zhao, Xiaolin Zhou, Chunzhen Fan, Zhiquan Wang, Zhan Jin, Ke Bei, Xiangyong Zheng, Min Zhao, Suqing Wu","doi":"10.1038/s41545-024-00354-1","DOIUrl":"10.1038/s41545-024-00354-1","url":null,"abstract":"Vallisneria spinulosa Yan (V.spinulosa Yan) with good ability of water purification is often used for ecological restoration of polluted water bodies. However, it is difficult to survive in turbid water bodies due to the low lighting condition. This study explored the feasibility of introducing artificial underwater light source into water bodies with high turbidity to strengthen the water restoration by V.spinulosa Yan. Addition of underwater light source promoted the clonal reproduction ability of V.spinulosa Yan, thus enhancing the removal loads of total nitrogen (TN), total phosphorus (TP), and nitrate nitrogen ( $${mathrm{NO}}^{-}_{3}{mbox{-}}{mathrm{N}}$$ ) by 1.60–3.43 × 10−2, 1.49–3.49 × 10−3, and 0.80–2.06 × 10−2 g m−2 d−1, respectively. Underwater light source significantly reduced the abundance of microbial community on V.spinulosa Yan leaves, as well as most nitrifying bacteria (Nitrosomonadaceae) and denitrifying bacteria (Nitrospira, Comamonadaceae, and Rhodocyclaceae) in the system. But the attachment of some Cyanophyta (Chloroplast and Cyanobacteria) and Photosynthetic bacteria (Rhodobacter) onto the leaves and the growth of Methyloligellaceae in water and sediments were promoted. Nitrogen and phosphorus removal by the growth system of V.spinulosa Yan without underwater light source mainly depended on the biological processes by functional bacteria, while the absorption and co-assimilation effect of V.spinulosa Yan with underwater light source.","PeriodicalId":19375,"journal":{"name":"npj Clean Water","volume":null,"pages":null},"PeriodicalIF":10.4,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41545-024-00354-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141597206","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-11DOI: 10.1038/s41545-024-00356-z
Yuyang Xie, Zhibin Wang, Sherif Ismail, Shou-Qing Ni
Dissimilatory nitrate reduction to ammonium (DNRA) received more attention for its ability to recover ammonium. This study investigated the possibility of low-frequency infrared electromagnetic field (IR-EMF) to improve DNRA. The optimal IR-EMF intensity of 0.04 μT could effectively improve DNRA activity of nonwoven fabric membrane bioreactors. In the long-term operation, the average ammonium conversion efficiency was enhanced by 117.7% and 62.5% under 0.04 μT and 0.06 μT IR-EMF, respectively. The highest nrfA-gene abundance and potential DNRA rate were obtained under 0.04 μT IR-EMF exposure. Bacteroidetes fragilis, Shewanelle oneidensis MR-1, and Thauera sp. RT1901 were selected to investigate the dynamic response of nitrogen transformation and energy metabolism to IR-EMF. The transcriptome sequencing and RT-qPCR results suggested that IR-EMF could enhance both denitrification and DNRA process, mainly by improving ATP synthesis to boost metabolic activity. This study provided an efficient method for the nitrogen recovery via DNRA process by applying IR-EMF.
{"title":"Long-term operation and dynamic response of dissimilatory nitrate reduction to ammonium process under low-frequency infrared electromagnetic field","authors":"Yuyang Xie, Zhibin Wang, Sherif Ismail, Shou-Qing Ni","doi":"10.1038/s41545-024-00356-z","DOIUrl":"10.1038/s41545-024-00356-z","url":null,"abstract":"Dissimilatory nitrate reduction to ammonium (DNRA) received more attention for its ability to recover ammonium. This study investigated the possibility of low-frequency infrared electromagnetic field (IR-EMF) to improve DNRA. The optimal IR-EMF intensity of 0.04 μT could effectively improve DNRA activity of nonwoven fabric membrane bioreactors. In the long-term operation, the average ammonium conversion efficiency was enhanced by 117.7% and 62.5% under 0.04 μT and 0.06 μT IR-EMF, respectively. The highest nrfA-gene abundance and potential DNRA rate were obtained under 0.04 μT IR-EMF exposure. Bacteroidetes fragilis, Shewanelle oneidensis MR-1, and Thauera sp. RT1901 were selected to investigate the dynamic response of nitrogen transformation and energy metabolism to IR-EMF. The transcriptome sequencing and RT-qPCR results suggested that IR-EMF could enhance both denitrification and DNRA process, mainly by improving ATP synthesis to boost metabolic activity. This study provided an efficient method for the nitrogen recovery via DNRA process by applying IR-EMF.","PeriodicalId":19375,"journal":{"name":"npj Clean Water","volume":null,"pages":null},"PeriodicalIF":10.4,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41545-024-00356-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141597198","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-07DOI: 10.1038/s41545-024-00353-2
Freya Mills, Tim Foster, Antoinette Kome, Rajeev Munankami, Gabrielle Halcrow, Antony Ndungu, Barbara Evans, Juliet Willetts
Halfway through the Sustainable Development Goal (SDG) period, there has been little research on the criteria for monitoring safely managed sanitation under SDG target 6.2. For reporting against SDGs, global indicators are necessarily limited and exclude many safety aspects from a public health perspective. Primary survey data from 31,784 households in seven countries in Asia and Africa were analysed, comparing estimates of safely managed on-site sanitation based on global indicators with five complementary indicators of safety: animal access to excreta, groundwater contamination, overdue emptying, entering containments to empty and inadequate protection during emptying. Application of additional criteria reduced the population with safely managed sanitation by 0.4–35% for specific indicators, with the largest impact due to the risk of groundwater contamination, animal access, and containments overdue for emptying. Combining these indicators across the service chain, excluding transport and treatment, found almost three-quarters of on-site systems currently assessed as safely managed with global indicators were considered unsafe based on complementary indicators. A more comprehensive assessment of safety of on-site sanitation can be achieved through these indicators, which could be integrated into national monitoring systems and used to inform sanitation investments that address local health-related risks.
{"title":"Indicators to complement global monitoring of safely managed on-site sanitation to understand health risks","authors":"Freya Mills, Tim Foster, Antoinette Kome, Rajeev Munankami, Gabrielle Halcrow, Antony Ndungu, Barbara Evans, Juliet Willetts","doi":"10.1038/s41545-024-00353-2","DOIUrl":"10.1038/s41545-024-00353-2","url":null,"abstract":"Halfway through the Sustainable Development Goal (SDG) period, there has been little research on the criteria for monitoring safely managed sanitation under SDG target 6.2. For reporting against SDGs, global indicators are necessarily limited and exclude many safety aspects from a public health perspective. Primary survey data from 31,784 households in seven countries in Asia and Africa were analysed, comparing estimates of safely managed on-site sanitation based on global indicators with five complementary indicators of safety: animal access to excreta, groundwater contamination, overdue emptying, entering containments to empty and inadequate protection during emptying. Application of additional criteria reduced the population with safely managed sanitation by 0.4–35% for specific indicators, with the largest impact due to the risk of groundwater contamination, animal access, and containments overdue for emptying. Combining these indicators across the service chain, excluding transport and treatment, found almost three-quarters of on-site systems currently assessed as safely managed with global indicators were considered unsafe based on complementary indicators. A more comprehensive assessment of safety of on-site sanitation can be achieved through these indicators, which could be integrated into national monitoring systems and used to inform sanitation investments that address local health-related risks.","PeriodicalId":19375,"journal":{"name":"npj Clean Water","volume":null,"pages":null},"PeriodicalIF":10.4,"publicationDate":"2024-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41545-024-00353-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141553384","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-04DOI: 10.1038/s41545-024-00341-6
Johannes Wagner, Johanna Koehler, Mikael Dupuis, Rob Hope
Africa lags behind the world on operational and financial progress to maintain safe drinking water services. In rural Mali, we explore the implications of monthly flat fee contributions and volumetric (pay-as-you-fetch) payments for water use and revenue generation. By assessing 4413 months of data across 177 handpumps, we find that once payment modalities switch from volumetric payments to monthly flat fees, a waterpoint registers a more than three-times higher monthly revenue. While flat fees cover a higher share of the operational costs of providing reliable water services, a subsidy gap persists. Flat fees appear to stimulate daily water use which more than doubles compared to volumetric payments. We estimate that a 1 °C increase in average monthly temperature is associated with 180 more litres of water used every day per handpump, emphasising the importance of climate-resilient water supplies. Based on these insights, we discuss the role of professional service delivery models to support reliable drinking water services for rural communities.
{"title":"Is volumetric pricing for drinking water an effective revenue strategy in rural Mali?","authors":"Johannes Wagner, Johanna Koehler, Mikael Dupuis, Rob Hope","doi":"10.1038/s41545-024-00341-6","DOIUrl":"10.1038/s41545-024-00341-6","url":null,"abstract":"Africa lags behind the world on operational and financial progress to maintain safe drinking water services. In rural Mali, we explore the implications of monthly flat fee contributions and volumetric (pay-as-you-fetch) payments for water use and revenue generation. By assessing 4413 months of data across 177 handpumps, we find that once payment modalities switch from volumetric payments to monthly flat fees, a waterpoint registers a more than three-times higher monthly revenue. While flat fees cover a higher share of the operational costs of providing reliable water services, a subsidy gap persists. Flat fees appear to stimulate daily water use which more than doubles compared to volumetric payments. We estimate that a 1 °C increase in average monthly temperature is associated with 180 more litres of water used every day per handpump, emphasising the importance of climate-resilient water supplies. Based on these insights, we discuss the role of professional service delivery models to support reliable drinking water services for rural communities.","PeriodicalId":19375,"journal":{"name":"npj Clean Water","volume":null,"pages":null},"PeriodicalIF":10.4,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41545-024-00341-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141521621","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-03DOI: 10.1038/s41545-024-00349-y
Yamini Javvadi, S. Venkata Mohan
The constantly evolving and growing global health crisis, antimicrobial resistance (AMR), endangers progress in medicine, food production, and life expectancy. Limited data on population-level prevalence, including seasonal and temporal variations, hampers accurate risk assessment for AMR transmission, despite its paramount importance on both global and national fronts. In this study, we used quantitative real-time PCR (q-PCR) to analyze 123 antibiotic resistance genes (ARGs) and 13 mobile genetic elements (MGEs) in wastewater of a selected urban community. Sampling was conducted monthly over a 5-month period (December 2021–April 2022) to assess resistance diversity, temporal dynamics, co-abundance of ARGs, MGEs, and resistance mechanisms. Approximately 50% of the tested ARG subtypes were consistently detected in all months, with frequency ranging from 52 to 61% with maximum absolute abundance in the winter months (December and January). In co-abundance analysis, specific genes were clustered into modules, highlighting shared distribution patterns and functional associations among the ARGs and MGEs. Detected clinically significant genes (ndm-1 and cfiA) and other variants (blaoxy, aph, aacC, tet-35, tet M, tet-32) are capable of imparting resistance to 3rd and 4th generation (gen) β-lactam, aminoglycoside, tetracycline, and multidrug classes. These contribute significantly to core/persistent resistance. This study deepens our comprehension of temporal/seasonal fluctuations in ARG and MGE distribution, providing valuable evidence to guide AMR control policies and promote responsible antibiotic/antimicrobial use for preserving effectiveness.
{"title":"Temporal dynamics and persistence of resistance genes to broad spectrum antibiotics in an urban community","authors":"Yamini Javvadi, S. Venkata Mohan","doi":"10.1038/s41545-024-00349-y","DOIUrl":"10.1038/s41545-024-00349-y","url":null,"abstract":"The constantly evolving and growing global health crisis, antimicrobial resistance (AMR), endangers progress in medicine, food production, and life expectancy. Limited data on population-level prevalence, including seasonal and temporal variations, hampers accurate risk assessment for AMR transmission, despite its paramount importance on both global and national fronts. In this study, we used quantitative real-time PCR (q-PCR) to analyze 123 antibiotic resistance genes (ARGs) and 13 mobile genetic elements (MGEs) in wastewater of a selected urban community. Sampling was conducted monthly over a 5-month period (December 2021–April 2022) to assess resistance diversity, temporal dynamics, co-abundance of ARGs, MGEs, and resistance mechanisms. Approximately 50% of the tested ARG subtypes were consistently detected in all months, with frequency ranging from 52 to 61% with maximum absolute abundance in the winter months (December and January). In co-abundance analysis, specific genes were clustered into modules, highlighting shared distribution patterns and functional associations among the ARGs and MGEs. Detected clinically significant genes (ndm-1 and cfiA) and other variants (blaoxy, aph, aacC, tet-35, tet M, tet-32) are capable of imparting resistance to 3rd and 4th generation (gen) β-lactam, aminoglycoside, tetracycline, and multidrug classes. These contribute significantly to core/persistent resistance. This study deepens our comprehension of temporal/seasonal fluctuations in ARG and MGE distribution, providing valuable evidence to guide AMR control policies and promote responsible antibiotic/antimicrobial use for preserving effectiveness.","PeriodicalId":19375,"journal":{"name":"npj Clean Water","volume":null,"pages":null},"PeriodicalIF":10.4,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41545-024-00349-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141496048","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-02DOI: 10.1038/s41545-024-00352-3
Yuyang Xie, Zhibin Wang, Shou-Qing Ni
Dissimilatory nitrate reduction to ammonium (DNRA) has garnered attention due to its ability to recover ammonia and reduce greenhouse gas emissions simultaneously. In this study, the potential of using static magnetic field (SMF) to improve DNRA process was explored from the sight of molecular biology. Functional genes, microbial community structure, and metabolism pathways were discussed. SMF of 40 mT shortened the start-up time of DNRA from 75 days to 41 days, while 80 mT SMF delayed it to 103 days. On day 80, DNRA potential rate under 40 mT SMF, reached 174 ± 11 μmol kg−1 h−1, significantly surpassing 0 mT (88 ± 6 μmol kg−1 h−1) and 80 mT SMF (52 ± 4 μmol kg−1 h−1). SMF of 40 mT also accelerated community succession and the enrichment of functional bacteria like Geobacter (from 15.71% to 32.11%). qPCR results suggested that 40 mT SMF promoted the rapid enrichment of DNRA functional gene nrfA and 80 mT SMF promoted the enrichment of nirS gene on day 40. Dynamic responses of Thauera sp. RT1901, Stutzerimonas stutzeri, Shewanella oneidensis MR-1, and Shewanella loihica PV-4 to SMF at transcriptional levels confirmed SMF could improve the nitrogen removal and electron transfer of DNRA and denitrification bacteria. Consequently, this work validated the possibility of using SMF to improve DNRA process for ammonia recovery and investigated the underlying mechanisms, which could promote the application of DNRA in full-scale.
{"title":"Using static magnetic field to recover ammonia efficiently by DNRA process","authors":"Yuyang Xie, Zhibin Wang, Shou-Qing Ni","doi":"10.1038/s41545-024-00352-3","DOIUrl":"10.1038/s41545-024-00352-3","url":null,"abstract":"Dissimilatory nitrate reduction to ammonium (DNRA) has garnered attention due to its ability to recover ammonia and reduce greenhouse gas emissions simultaneously. In this study, the potential of using static magnetic field (SMF) to improve DNRA process was explored from the sight of molecular biology. Functional genes, microbial community structure, and metabolism pathways were discussed. SMF of 40 mT shortened the start-up time of DNRA from 75 days to 41 days, while 80 mT SMF delayed it to 103 days. On day 80, DNRA potential rate under 40 mT SMF, reached 174 ± 11 μmol kg−1 h−1, significantly surpassing 0 mT (88 ± 6 μmol kg−1 h−1) and 80 mT SMF (52 ± 4 μmol kg−1 h−1). SMF of 40 mT also accelerated community succession and the enrichment of functional bacteria like Geobacter (from 15.71% to 32.11%). qPCR results suggested that 40 mT SMF promoted the rapid enrichment of DNRA functional gene nrfA and 80 mT SMF promoted the enrichment of nirS gene on day 40. Dynamic responses of Thauera sp. RT1901, Stutzerimonas stutzeri, Shewanella oneidensis MR-1, and Shewanella loihica PV-4 to SMF at transcriptional levels confirmed SMF could improve the nitrogen removal and electron transfer of DNRA and denitrification bacteria. Consequently, this work validated the possibility of using SMF to improve DNRA process for ammonia recovery and investigated the underlying mechanisms, which could promote the application of DNRA in full-scale.","PeriodicalId":19375,"journal":{"name":"npj Clean Water","volume":null,"pages":null},"PeriodicalIF":10.4,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41545-024-00352-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141489639","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-02DOI: 10.1038/s41545-024-00346-1
Weiliang Bai, Ruizhe Xu, Mircea Podar, Cynthia M. Swift, Navid B. Saleh, Frank E. Löffler, Pedro J. J. Alvarez, Manish Kumar
Municipal drinking water distribution systems (DWDSs) and associated premise plumbing (PP) systems are vulnerable to proliferation of opportunistic pathogens, even when chemical disinfection residuals are present, thus presenting a public health risk. Monitoring the structure of microbial communities of drinking water is challenging because of limited continuous access to faucets, pipes, and storage tanks. We propose a scalable household sampling method, which uses spent activated carbon and reverse osmosis (RO) membrane point-of-use (POU) filters to evaluate mid- to long-term occurrence of microorganisms in PP systems that are relevant to consumer exposure. As a proof of concept, POU filter microbiomes were collected from four different locations and analyzed with 16S rRNA gene amplicon sequencing. The analyses revealed distinct microbial communities, with occasional detection of potential pathogens. The findings highlight the importance of local, and if possible, continuous monitoring within and across distribution systems. The continuous operation of POU filters offers an advantage in capturing species that may be missed by instantaneous sampling methods. We suggest that water utilities, public institutions, and regulatory agencies take advantage of end-of-life POU filters for microbial monitoring. This approach can be easily implemented to ensure drinking water safety, especially from microbes of emerging concerns; e.g., pathogenic Legionella and Mycobacterium species.
市政饮用水输配系统 (DWDS) 和相关的场所管道系统 (PP) 很容易受到机会性病原体扩散的影响，即使在存在化学消毒残留物的情况下也是如此，从而带来了公共卫生风险。由于连续接触水龙头、管道和储水箱的机会有限，因此监测饮用水微生物群落结构具有挑战性。我们提出了一种可扩展的家庭采样方法，该方法使用废活性炭和反渗透膜使用点过滤器（POU）来评估与消费者接触有关的中长期水处理系统中微生物的发生情况。作为概念验证，从四个不同地点收集了 POU 过滤器微生物组，并用 16S rRNA 基因扩增子测序法进行了分析。分析结果显示了不同的微生物群落，偶尔还能检测到潜在的病原体。这些发现强调了在本地以及在可能的情况下对输水系统内部和整个输水系统进行连续监测的重要性。POU 过滤器的连续运行在捕捉瞬时采样方法可能遗漏的物种方面具有优势。我们建议供水公司、公共机构和监管机构利用报废的 POU 过滤器进行微生物监测。这种方法易于实施，可确保饮用水安全，尤其是新出现的微生物，如致病性军团菌和分枝杆菌。
{"title":"Point-of-use filtration units as drinking water distribution system sentinels","authors":"Weiliang Bai, Ruizhe Xu, Mircea Podar, Cynthia M. Swift, Navid B. Saleh, Frank E. Löffler, Pedro J. J. Alvarez, Manish Kumar","doi":"10.1038/s41545-024-00346-1","DOIUrl":"10.1038/s41545-024-00346-1","url":null,"abstract":"Municipal drinking water distribution systems (DWDSs) and associated premise plumbing (PP) systems are vulnerable to proliferation of opportunistic pathogens, even when chemical disinfection residuals are present, thus presenting a public health risk. Monitoring the structure of microbial communities of drinking water is challenging because of limited continuous access to faucets, pipes, and storage tanks. We propose a scalable household sampling method, which uses spent activated carbon and reverse osmosis (RO) membrane point-of-use (POU) filters to evaluate mid- to long-term occurrence of microorganisms in PP systems that are relevant to consumer exposure. As a proof of concept, POU filter microbiomes were collected from four different locations and analyzed with 16S rRNA gene amplicon sequencing. The analyses revealed distinct microbial communities, with occasional detection of potential pathogens. The findings highlight the importance of local, and if possible, continuous monitoring within and across distribution systems. The continuous operation of POU filters offers an advantage in capturing species that may be missed by instantaneous sampling methods. We suggest that water utilities, public institutions, and regulatory agencies take advantage of end-of-life POU filters for microbial monitoring. This approach can be easily implemented to ensure drinking water safety, especially from microbes of emerging concerns; e.g., pathogenic Legionella and Mycobacterium species.","PeriodicalId":19375,"journal":{"name":"npj Clean Water","volume":null,"pages":null},"PeriodicalIF":10.4,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41545-024-00346-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141489605","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-28DOI: 10.1038/s41545-024-00350-5
Anna Salvian, Daniel Farkas, Marina Ramirez-Moreno, Daniela Torruella-Salas, Antonio Berná, Claudio Avignone-Rossa, John R. Varcoe, Abraham Esteve-Núñez, Siddharth Gadkari
Efficient wastewater treatment monitoring is vital for addressing water scarcity. Microbial fuel cells (MFCs) have emerged as real-time biosensors for biochemical oxygen demand (BOD) in urban wastewater. Discrepancies in signal generation may arise due to changes in the composition and metabolism of mixed-culture electroactive biofilms stemming from different wastewater compositions. In this study, 3D-printed MFC-based biosensors were employed to assess the BOD of sterile complex artificial wastewater and untreated urban wastewater. Alterations in the microbial composition of the anode were evaluated using 16S rRNA sequencing and metagenomics analysis. Results show that MFC-based biosensors can be effectively recalibrated for diverse types of wastewater, maintaining consistent sensitivity (0.64 ± 0.10 mA L mg−1 m−2 with synthetic wastewater and 0.78 ± 0.13 mA L mg−1 m−2 with urban wastewater) and limit of detection (49 ± 8 mg L−1 for synthetic wastewater and 44 ± 7 mg L−1 for urban wastewater). Crucially, pre-sterilization, conductivity adjustments, and nitrogen purging of wastewater are not required before its introduction into the biosensor. However, the presence of native aerobic microorganisms in the wastewater might affect the current output. Metagenomics and taxonomic analyses revealed that the alterations in biofilm composition are predominantly in response to the varied chemical and microbiological compositions of different substrates. Despite variations in anodic biofilm composition, the MFC-based biosensor maintains a relative error comparable to the standard BOD test. This highlights the resilience and flexibility of the biosensor when directly used with a variety of wastewater types before full biofilm adjustment.
高效的废水处理监测对于解决水资源短缺问题至关重要。微生物燃料电池（MFC）已成为城市污水生化需氧量（BOD）的实时生物传感器。由于废水成分不同，混合培养的电活性生物膜的组成和新陈代谢可能会发生变化，从而导致信号产生的差异。本研究采用基于三维打印 MFC 的生物传感器来评估无菌复合人工废水和未经处理的城市污水的生化需氧量。使用 16S rRNA 测序和元基因组学分析评估了阳极微生物组成的变化。结果表明，基于 MFC 的生物传感器可针对不同类型的废水进行有效的重新校准，并保持一致的灵敏度（合成废水为 0.64 ± 0.10 mA L mg-1 m-2，城市污水为 0.78 ± 0.13 mA L mg-1 m-2）和检测限（合成废水为 49 ± 8 mg L-1，城市污水为 44 ± 7 mg L-1）。最重要的是，在将废水引入生物传感器之前，无需对废水进行预灭菌、电导率调整和氮气净化。不过，废水中存在的原生好氧微生物可能会影响电流输出。元基因组学和分类学分析表明，生物膜组成的变化主要是对不同基质的不同化学和微生物组成的反应。尽管阳极生物膜的组成发生了变化，但基于 MFC 的生物传感器仍能保持与标准 BOD 测试相当的相对误差。这突出表明，在生物膜完全调整之前，生物传感器可直接用于各种废水类型，具有很强的适应性和灵活性。
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Pub Date : 2024-06-25DOI: 10.1038/s41545-024-00348-z
Qidong Yin, Kai He, Gavin Collins, Jo De Vrieze, Guangxue Wu
Microbial metabolism upholds a fundamental role in the sustainability of water ecosystems. However, how microorganisms surviving in low-concentration substrate water environments, including the existence of emerging compounds of interest, remains unclear. In this review, microbial strategies for concentrating, utilizing, and metabolizing of low concentration substrates were summarized. Microorganisms develop substrate-concentrating strategies at both the cell and aggregate levels in substrate-limited settings. Following, microbial uptake and transport of low-concentration substrates are facilitated by adjusting physiological characteristics and shifting substrate affinities. Finally, metabolic pathways, such as mixed-substrate utilization, syntrophic metabolism, dynamic response to nutrient variation, and population density-based mechanisms allow microorganisms to efficiently utilize low-concentration substrates and to adapt to challenging oligotrophic environments. All these microbial strategies will underpin devising new approaches to tackle environmental challenges and drive the sustainability of water ecosystems, particularly in managing low-concentration contaminants (i.e., micropollutants).
{"title":"Microbial strategies driving low concentration substrate degradation for sustainable remediation solutions","authors":"Qidong Yin, Kai He, Gavin Collins, Jo De Vrieze, Guangxue Wu","doi":"10.1038/s41545-024-00348-z","DOIUrl":"10.1038/s41545-024-00348-z","url":null,"abstract":"Microbial metabolism upholds a fundamental role in the sustainability of water ecosystems. However, how microorganisms surviving in low-concentration substrate water environments, including the existence of emerging compounds of interest, remains unclear. In this review, microbial strategies for concentrating, utilizing, and metabolizing of low concentration substrates were summarized. Microorganisms develop substrate-concentrating strategies at both the cell and aggregate levels in substrate-limited settings. Following, microbial uptake and transport of low-concentration substrates are facilitated by adjusting physiological characteristics and shifting substrate affinities. Finally, metabolic pathways, such as mixed-substrate utilization, syntrophic metabolism, dynamic response to nutrient variation, and population density-based mechanisms allow microorganisms to efficiently utilize low-concentration substrates and to adapt to challenging oligotrophic environments. All these microbial strategies will underpin devising new approaches to tackle environmental challenges and drive the sustainability of water ecosystems, particularly in managing low-concentration contaminants (i.e., micropollutants).","PeriodicalId":19375,"journal":{"name":"npj Clean Water","volume":null,"pages":null},"PeriodicalIF":10.4,"publicationDate":"2024-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41545-024-00348-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141452747","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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