Water Research最新文献

{"title":"Distinct response of nitrogen metabolism to exogenous cadmium (Cd) in river sediments with and without Cd contamination history","authors":"Aomei Guan, Qiang Peng, Weihang Zhang, Weixiao Qi, Chengzhi Hu, Jiuhui Qu","doi":"10.1016/j.watres.2025.123104","DOIUrl":"https://doi.org/10.1016/j.watres.2025.123104","url":null,"abstract":"The role of metal resistance on nitrogen metabolism function and community resilience against Cd is important for elucidating the evolutionary dynamics of key ecological functions in river ecosystems. In this study, the response of nitrogen transforming function to Cd exposure in river sediments from the Yangtze River Basin with varying levels of heavy metal contamination history (Cd-contaminated and Cd-free sediments) was compared to understand how Cd influenced nitrogen metabolism under varying metal resistance conditions. The results showed that chronic and persistent Cd pollution of sediments caused an elevation of transport efflux metal resistance genes (MRGs) and a reduction in the uptake MRGs, leading to a stronger tolerance to Cd for Cd-contaminated sediment than Cd-free ones. Specifically, denitrification, anaerobic ammonium oxidation (anammox) and dissimilatory nitrate reduction to ammonium (DNRA) respectively responded to Cd through different mechanisms. Exogenous Cd (5-100 mg/kg) influenced denitrification rates (-70%∼100% deviation to control group) by regulating key genera (<em>Thiobacillus, Magnetospirillum, Sideroxydans</em> etc.) and gene clusters for denitrification. Both adaptive nature of anammox bacteria and co-regulation of key genera (<em>Candidatus_Scalindua, Candidatus_Jettenia, Planctomyces</em> etc.) and gene <em>hzsA</em> were drivers of differential responses in sediments from various contamination history. Environmental factors rather than contamination history, key genera or genes were probably critical ones determining Cd-resistance in DNRA, being more tolerant to Cd in sediments with higher TOC and NH₄⁺. Stimulation of N₂O reduction process (genera <em>Gemmatimonas</em> and <em>Gemmatirosa</em> and genes <em>nosZ</em>) in Cd-contaminated sediments by exogenous Cd lowered N₂O emission risk, whereas the reverse was true for Cd-free sediments. These results enrich our understanding about the linkages among MRGs and nitrogen reduction functions in river.","PeriodicalId":443,"journal":{"name":"Water Research","volume":"21 1","pages":""},"PeriodicalIF":12.8,"publicationDate":"2025-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142934984","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}

{"title":"Photic versus Aphotic Production of Organohalogens from Native versus Invasive Wetland Plants-Derived Dissolved Organic Matter","authors":"Yu Fu, Xueqi Hu, Pu Wang, Qingchao Li, Lingli Wang, Jialin Chen, Zhaohui Wang","doi":"10.1016/j.watres.2025.123103","DOIUrl":"https://doi.org/10.1016/j.watres.2025.123103","url":null,"abstract":"The aphotic formation of natural organohalogens (NOHs) remains inadequately understood, in contrast to the well-documented photo-halogenation process of dissolved organic matter (DOM), despite the significant biogeochemical implications associated with NOHs. This study investigates the differences in the formation of chlorinated and brominated compounds from the photochemical and aphotic reactions of native <em>Phragmites australis</em> (PA-DOM) and invasive <em>Spartina alterniflora</em> (SA-DOM). The findings indicate that SA-DOM exhibits a greater potential for photochemical halogenation, attributed to its higher aromatic content and enhanced photostability. Utilizing advanced mass spectrometry, the study identifies nitrogen-containing and free saturated compounds as primary precursors for both types of DOM during photochemical halogenation. Notably, significant disparities in the halogenation processes of lignin/CRAM, nitrogen-containing/free saturated compounds, and amino sugars between SA-DOM and PA-DOM are observed, leading to a higher production of NOHs in PA-DOM during aphotic reactions compared to photic reactions, even in artificial seawater. Furthermore, the study emphasizes the critical role of dissolved oxygen in the formation of NOHs from PA-DOM under aphotic conditions. Given the rapid fluctuations in oxygen levels, salinity, and solar intensity, alongside tidal and diurnal cycles, the significance of both photic and aphotic pathways for NOHs formation should not be overlooked.","PeriodicalId":443,"journal":{"name":"Water Research","volume":"99 1","pages":""},"PeriodicalIF":12.8,"publicationDate":"2025-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142934787","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}

{"title":"Leveraging Almost Hydrophobic PVDF Membrane and In-situ Ozonation in O3/UF/BAC System for Superior Anti-fouling and Rejection Performance in Drinking Water Treatment","authors":"Haiyang He, Xiao Wang, Xia Huang, Xiaomao Wang, Hongtao Zhu, Fengxiang Chen, Xianzhi Wu, Huifeng Wu, Jun Ma, Xianghua Wen","doi":"10.1016/j.watres.2025.123105","DOIUrl":"https://doi.org/10.1016/j.watres.2025.123105","url":null,"abstract":"The almost hydrophobic PVDF membrane (PVDF matrix) commonly exhibited excellent performance in pollutant rejection but with poor anti-fouling performance. This study intended to develop the rejection performance and enhance anti-fouling of the PVDF membrane in an O₃/UF/BAC system for high quality water production through leveraging the advantages of <em>in-situ</em> ozonation and the nature of the PVDF membrane. Reduced density gradient (RDG) analysis demonstrated that the PVDF membrane exhibited excellent ozone resistance by reducing hydrogen bonds and electrostatic interactions between the membrane surface and ozone. Consequently, the physicochemical properties of the PVDF membrane remained unchanged in the laboratory continuous flow experiment with <em>in-situ</em> ozonation at 2.86 mg/L. The almost hydrophobicity of the PVDF membrane not only resisted fouling but also facilitated the reaction between ozone and foulants of higher concentrations locally at membrane surface, leading to dynamic changes in membrane fouling, with TMP/TMP₀ initially increasing, then decreasing and stable. Therefore, the <em>R_total, R_cake</em> and <em>R_gel</em> of the PVDF membrane decreased by 47.40%, 46.79% and 50.99% as compared to the UF/BAC system, respectively, in the O₃/UF/BAC system. <em>In-situ</em> ozonation transformed macromolecular substances into micromolecules, particularly organic matter with lignin/carboxylic-rich alicyclic molecules and aromatic structures. The majority of these micromolecules were either rejected by the deposited foulants layer through Van der Waals interaction and utilized as a carbon source by membrane surface microorganisms (eg., <em>Curvibacter</em> and <em>Methyloversatilis</em>), or further degraded by microorganism in the BAC unit. This resulted in a 19.34% and 40.58% reduction in COD_Mn concentrations in the UF and BAC effluents, respectively. The system's anti-fouling and water purification performance observed in laboratory experiments was confirmed in a pilot test, providing new insights into the use of <em>in-situ</em> ozonation and organic membranes.","PeriodicalId":443,"journal":{"name":"Water Research","volume":"79 1","pages":""},"PeriodicalIF":12.8,"publicationDate":"2025-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142934791","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}

{"title":"Multi-stage optimization framework for synergetic grey-green infrastructure in response to long-term climate variability based on shared socio-economic pathways","authors":"Shiqi Zhou, Haifeng Diao, Jiahui Wang, Weiyi Jia, Haowen Xu, Xiaodong Xu, Mo Wang, Chuanhao Sun, Renlu Qiao, Zhiqiang Wu","doi":"10.1016/j.watres.2025.123091","DOIUrl":"https://doi.org/10.1016/j.watres.2025.123091","url":null,"abstract":"Global climate change and rapid urbanization have increasingly intensified extreme rainfall events and surface runoff, posing significant challenges to urban hydrological security. Synergetic Grey-Green Infrastructure (SGGI) has been widely applied to enhance stormwater management in urban areas. However, current research primarily focused on optimizing and evaluating either grey infrastructure (GREI) or green infrastructure (GI) under single rainfall event, neglecting the non-stationary impacts of long-term climate change on infrastructure performance. Therefore, this study introduced a multi-stage optimization framework for SGGI layouts based on shared socio-economic pathways, utilizing graph theory and genetic algorithms to identify optimal solutions through life cycle cost (LCC) and hydraulic reliability in response to varying climate change scenarios. A case study of Shenzhen, China, was conducted to validate this method. The results indicated that: (1) SSP2-4.5 and SSP5-8.5 scenarios revealed significant phase-specific variations in Shenzhen's annual precipitation series; (2) The optimized SGGI layouts yielded substantial LCC savings compared to GREI, with centralized and decentralized strategies achieving reductions of 6.6% and 4.7%, respectively. (3) The SGGI adapted to extreme rainfall conditions by shifting preference from permeable pavements to bioretention cells; (4) The Change-GREI&amp;GI (CGG) strategy consistently outperformed the Change-only-GI (COG) strategy in LCC control and hydraulic reliability, particularly a 1.68% cost advantage under extreme scenarios. These findings highlight the critical role of multi-stage optimization in improving the cost-effectiveness and resilience of integrated grey-green infrastructure systems, providing valuable insights for designing adaptive SGGI strategies that effectively respond to long-term climate variability in urban environments.","PeriodicalId":443,"journal":{"name":"Water Research","volume":"28 1","pages":""},"PeriodicalIF":12.8,"publicationDate":"2025-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142934986","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}

{"title":"Longitudinal metagenomic analysis on antibiotic resistome, mobilome, and microbiome of river ecosystems in a sub-tropical metropolitan city","authors":"Xuemei Mao, Xiaole Yin, Yu Yang, Fangzhou Gao, Shuxian Li, Xianghui Shi, Yu Deng, Liguan Li, Kenneth M.Y. Leung, Tong Zhang","doi":"10.1016/j.watres.2025.123102","DOIUrl":"https://doi.org/10.1016/j.watres.2025.123102","url":null,"abstract":"Rivers play an important role as reservoirs and sinks for antibiotic resistance genes (ARGs). However, it remains underexplored for the resistome and associated mobilome in river ecosystems, and hosts of riverine ARGs particularly the pathogenic ones are rarely studied. This study for the first time conducted a longitudinal metagenomic analysis to unveil the resistome, mobilome, and microbiome in river water, by collecting samples from 16 rivers in Hong Kong over a three-year period and using both short-read and long-read sequencing. Results revealed that aminoglycoside, bacitracin, β-lactam, macrolide lincosamide-streptogramin, and sulfonamide were the predominant ARG types in the river water samples. Riverine ARGs exhibited high spatial variations in abundance and diversity. Environmental factors such as fecal coliform count, <em>Escherichia coli</em> count, 5-day biochemical oxygen demand (BOD₅), dissolved oxygen (DO), and total organic carbon (TOC) had a significant correlation to the absolute concentrations of ARGs. Nanopore sequencing was used to reveal the physical genetic linkage of mobile genetic elements (MGEs) with ARGs in river water samples. The results showed that qacEdelta, transposase, integrase, and Tn916 had a high prevalence in ARG-carrying long reads. Host tracking using ARG-carrying reads identified 23 pathogenic bacteria species harbored ARGs. Some ARGs were shared by different bacterial groups. This study presented a nuanced insight of resistome in river water by a longitudinal metagenomic analysis and deepened our understanding of common and divergent riverine antimicrobial resistant risk across the regional patterns.","PeriodicalId":443,"journal":{"name":"Water Research","volume":"68 1","pages":""},"PeriodicalIF":12.8,"publicationDate":"2025-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142925199","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}

{"title":"Lithium complexing strategy based on host-guest recognition for efficient Mg2+/Li+ separation","authors":"Xiangmin Xu, Xiaowei Zhu, Jinchao Chen, Xingran Zhang, Zhiwei Wang, Fang Li","doi":"10.1016/j.watres.2025.123100","DOIUrl":"https://doi.org/10.1016/j.watres.2025.123100","url":null,"abstract":"Ion selective membranes with precise Mg²⁺/Li⁺ separation have attracted extensive interest in lithium extraction to circumvent the lithium supply shortage. However, realizing this target remains a significant challenge mainly due to a high concentration ratio of Mg²⁺/Li⁺ as well as the relatively close ionic hydration radius and chemical. Herein, inspired by the host-guest recognition between alkali-metal ions and crown ether (CE), a novel approach was proposed to regulate the membrane internal structure by introducing CE to strengthen the complexation between Li⁺ and CE. The CE modified membranes achieved the unique outcome of “Li⁺ rejection-Mg²⁺ permeation” deriving from enhanced solubility (<em>K_S</em>) and retarded diffusivity (<em>D_S</em>) of Li⁺ compared to that of Mg²⁺. The Mg²⁺/Li⁺ separation factors for MgSO₄/Li₂SO₄ and MgCl₂/LiCl of modified membranes (<em>i.e.,</em> 20.1 and 17.7) are about 21.9 and 19.9 time higher than that of pristine membranes, respectively. The results from density function theory (DFT) indicated that the stronger host-guest interaction between CE and Li⁺ combined them closely, thereby increasing solubility and reducing diffusivity of Li⁺. Our findings develop a new efficient membrane-based strategy enabling the production of high-purity lithium salts from simulated brine.","PeriodicalId":443,"journal":{"name":"Water Research","volume":"76 1","pages":""},"PeriodicalIF":12.8,"publicationDate":"2025-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142925200","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}

{"title":"Multi-omics Reveals Mechanism of Hydroxylamine-Enhanced Ultimate Nitrogen Removal in Pilot-Scale Anaerobic/Aerobic/Anoxic System","authors":"You Wu, Hanbin Wang, Liang Zhang, Wei Zeng, Yongzhen Peng","doi":"10.1016/j.watres.2025.123101","DOIUrl":"https://doi.org/10.1016/j.watres.2025.123101","url":null,"abstract":"Hydroxylamine (HA) dosing is an effective strategy for promoting partial nitrification (PN); however, its impact on endogenous denitrification remains underexplored. In this study, long-term continuous HA dosing (1.4 mg/L) was introduced for over 110 days in a pilot-scale anaerobic/aerobic/anoxic (AOA) system treating municipal wastewater (66.7-75 m³/d). The HA dosing significantly increased the nitrite accumulation ratio to 67.6 ± 5.0 % (<em>p</em>&lt;0.001) and reduced the effluent total inorganic nitrogen concentration from 6.2 ± 2.0 to 2.4 ± 1.1 mg/L (<em>p</em>&lt;0.001), achieving a nitrogen removal efficiency of 87.4 ± 4.5% (<em>p</em>&lt;0.001) at a hydraulic retention time of 8 hours. During the HA dosing, aerobic nitrogen removal contribution increased from 2.4 ± 3.4 % to 25.8 ± 8.1 % (<em>p</em>&lt;0.001), and the anoxic nitrogen removal rate improved from 1.63 ± 0.11 to 2.35 ± 0.13 mg N/(L·h) (<em>p</em>&lt;0.001). Enhanced nitrogen removal was not only achieved through the rapid establishment of PN but also driven by the long-term impact of HA dosing on microbial community dynamics. Multi-omics analyses revealed that HA disrupted the polyphosphate (poly-P) cycle, evidenced by enhanced transcription of <em>ppx</em> (poly-P degradation) and suppressed <em>ppk</em> (poly-P synthesis), thereby reducing energy availability for phosphate-accumulating organisms (PAOs) and shifting the carbon source competition toward glycogen-accumulating organisms (GAOs), with <em>Ca.</em> Competibacter abundance increased from 0.16% to 1.13% (<em>p</em> &lt; 0.001). The economic analysis demonstrated that HA reduced sludge production by 11.2% and saved operating costs by 31.4–42.8% compared to conventional carbon sources. These findings highlight the potential of HA dosing to achieve sustainable and highly efficient wastewater treatment.","PeriodicalId":443,"journal":{"name":"Water Research","volume":"37 1","pages":""},"PeriodicalIF":12.8,"publicationDate":"2025-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142925198","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}

{"title":"Integrated real-time intelligent control for wastewater treatment plants: data-driven modeling for enhanced prediction and regulatory strategies","authors":"Wei Dai, Ji-Wei Pang, Jie Ding, Jing-hui Wang, Chi Xu, Lu-Yan Zhang, Nan-Qi Ren, Shan-Shan Yang","doi":"10.1016/j.watres.2025.123099","DOIUrl":"https://doi.org/10.1016/j.watres.2025.123099","url":null,"abstract":"Both mechanical models and machine learning-based models are widely utilized for real-time dynamic control; however, their implementation in the water sector often incurs significant data and computational costs. To address these challenges, this study introduces an innovative feature extraction method designed to enhance the cost-effectiveness of dynamic control in wastewater treatment plants. The proposed method extracts dynamic features from time-series data of key substrate variables to construct a data-driven model and develop real-time control strategies. The results indicate that the data-driven model accurately predicts the variation trends of ammonia nitrogen, total nitrogen, and biochemical oxygen demand, with correlation coefficients exceeding 0.8. Compared to the traditional activated sludge 2D model, the proposed approach significantly improves computational efficiency, reducing model parameter calibration time from 939.75 seconds to 87.52 seconds. Furthermore, the developed real-time control strategies reduce energy consumption by up to 24.3% while ensuring effluent quality meets discharge standards. The inclusion of a dynamic update mechanism, which refreshes model parameters every three hours, further enhances system adaptability and responsiveness. In conclusion, the proposed method minimizes reliance on complex water quality, sludge, and environmental datasets by directly extracting dynamic biochemical characteristics from key variables, providing a cost-effective solution for dynamic control in wastewater management.","PeriodicalId":443,"journal":{"name":"Water Research","volume":"76 1","pages":""},"PeriodicalIF":12.8,"publicationDate":"2025-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142925139","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}

{"title":"Design and optimization of hybrid seawater reverse osmosis–solar-driven desalination–pressure retarded osmosis system for energy efficient desalination maximizing economic potential","authors":"Sunwoo Kim, Jieun Jang, Jonghun Lim, Dongha Lee, Jeonghun Kim, Junghwan Kim","doi":"10.1016/j.watres.2024.123066","DOIUrl":"https://doi.org/10.1016/j.watres.2024.123066","url":null,"abstract":"Seawater reverse osmosis (SWRO)–pressure retarded osmosis (PRO) hybrid desalination system is being actively researched to reduce energy consumption by generating energy in the PRO. However, the SWRO–PRO hybrid system still faces the following challenges: low freshwater recovery and low energy generation. To resolve these challenges, this study first proposes a novel SWRO–Solar-driven desalination (SD)–PRO hybrid system for energy-efficient desalination. The proposed system comprises three major processes: SWRO for freshwater recovery, SD for freshwater recovery, and PRO for energy generation. First, the pressurized seawater passes through a semi-permeable SWRO membrane to produce freshwater, and the remaining concentrated brine enters the SD system. Second, an evaporator, that absorbs solar energy and quickly evaporates water floats on the SD system to recover additional freshwater. Third, the highly concentrated brine that remains unevaporated is used as a draw solution in PRO to generate energy. Consequently, the total freshwater recovery is increased by 14.54%, the specific energy consumption is reduced by 38.86%, and the levelized cost of the freshwater is reduced by 16.67% compared with the conventional SWRO–PRO system. Furthermore, the life cycle assessment results demonstrate that the proposed system is environmentally friendly. These results indicate that the proposed system is a feasible solution for sustainable desalination.","PeriodicalId":443,"journal":{"name":"Water Research","volume":"28 1","pages":""},"PeriodicalIF":12.8,"publicationDate":"2025-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142924562","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}

{"title":"FeO might be more suitable than Fe2+ for the construction of anammox-dominated Fe-N coupling system: based on 15N isotope tracing","authors":"Fangxu Jia, Yao Chen, Zhicheng Xu, Xinyu Gao, Ning Mei, Xin Qi, Lijun Yang, Jie Jiang, Lu Hou, Hong Yao","doi":"10.1016/j.watres.2025.123097","DOIUrl":"https://doi.org/10.1016/j.watres.2025.123097","url":null,"abstract":"Iron not only influences the activity of anammox bacteria (AnAOB) but also participates in complex Fe-N cycles. In this study, the advanced ¹⁵N isotope tracing method was set up to quantify the potential rates of full nitrogen metabolic pathways under different ferrous iron (Fe²⁺ and FeO) within two identical anammox granular reactors. The results indicated that both Fe²⁺ and FeO enhanced AnAOB activity. However, compared to Fe²⁺, which readily precipitates and oxidizes, the system supplemented with FeO exhibited higher Fe-N metabolic activity and greater metabolic diversity. This is attributed to the gradual release of Fe²⁺ from FeO, providing a sustainable and stable supply of Fe²⁺ for microorganisms. Furthermore, <em>Subgroup_10</em> and <em>Paludibaculum</em> were identified as potential functional bacteria for feammox, while <em>Denitratisoma, I-8</em> and <em>Arenimonas</em> were for NDFO. These results suggest that FeO addition is more beneficial for the construction of a Fe-N coupling system. Overall, this study enhances our understanding of how with exogenous iron can strengthen the anammox system, laying a theoretical foundation for the development of anammox-dominant Fe-N coupling systems.","PeriodicalId":443,"journal":{"name":"Water Research","volume":"05 1","pages":""},"PeriodicalIF":12.8,"publicationDate":"2025-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142925201","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}