Water Research最新文献

{"title":"Built-in electric field of Ag2Se thermoelectric effect activated persulfate for humic acid decomposition in water: Molecular transformation mechanism","authors":"Qiuling Ma ,&nbsp;Xiangqian Tan ,&nbsp;Miao Fang ,&nbsp;Zhiyuan Ning ,&nbsp;He Guo ,&nbsp;Guodong Zhang ,&nbsp;Jian Zhou ,&nbsp;Tiecheng Wang","doi":"10.1016/j.watres.2025.123717","DOIUrl":"10.1016/j.watres.2025.123717","url":null,"abstract":"<div><div>Water temperature fluctuations directly impact pollutant decomposition processes in wastewater. Thermoelectric effect is considered an alternative to utilize these temperature variations for pollution control. In this study, a system for persulfate (PS) activation by Ag₂Se thermoelectric catalyst under water temperature gradients (Ag₂Se/Δ_T/PS) was developed for humic acid (HA) degradation in water. The experimental results showed that the Ag₂Se/Δ_T/PS system achieved a 90.7 % HA removal efficiency, outperforming both PS/Δ_T (PS with temperature gradients) and Ag₂Se/Δ_T systems. Thermoelectric simulations indicated that Ag₂Se generated an electric field under temperature variations, with higher current density at surface pores where polarized charges efficiently activated PS. Density functional theory calculations revealed that the thermoelectric effect of Ag₂Se lowered the energy barriers for PS activation and ·SO₄⁻ generation. Different from ·OH-led decomposition of HA in the Ag₂Se/Δ_T system, ·SO₄⁻ and ·OH dominated HA decomposition in the Ag₂Se/Δ_T/PS system, and ¹O₂ also contributed this process. Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR MS) revealed that oxidation, decarboxylation, and sulfidation were the primary pathways driving HA degradation, leading to decreases in CHO-containing compounds and formation of S-rich byproducts. These findings highlighted the potential of thermoelectric catalysts in advancing water treatment technologies.</div></div>","PeriodicalId":443,"journal":{"name":"Water Research","volume":"281 ","pages":"Article 123717"},"PeriodicalIF":11.4,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143866569","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":"Mechanistic insights and performance of Mn redox cycling in a dual-bacteria bioreactor for ammonium and Cr(VI) removal","authors":"Yue Wang ,&nbsp;Yihan Bai ,&nbsp;Liang Xu ,&nbsp;Junfeng Su ,&nbsp;Jingting Feng ,&nbsp;Ying Zhang ,&nbsp;Wenjing Cheng ,&nbsp;Jiangtao Bai","doi":"10.1016/j.watres.2025.123713","DOIUrl":"10.1016/j.watres.2025.123713","url":null,"abstract":"<div><div>The co-contamination of hexavalent chromium (Cr(VI)) and ammonium (NH₄⁺-N) in industrial wastewater has attracted considerable attention due to its serious threats to both ecological systems and public health. Manganese(IV) (Mn(IV))-driven NH₄⁺-N oxidation (Mnammox) coupled with Mn(II)-mediated denitrification (MnOD), built on the Mn redox cycle, is a promising nitrogen removal process, where Mn(II) and NO_x⁻-N generated during Mnammox were effectively controlled by MnOD. Herein, a bioreactor integrating Mnammox and MnOD for NH₄⁺-N and Cr(VI) removal was constructed utilizing core-shell gel beads embedded with two core strains and δ-MnO₂. When the C/N was 1.5, pH was 6.5, and HRT was 20 h, the removal efficiencies for Cr(VI) and NH₄⁺-N reached 96.3 and 91.3 %, respectively. Cr(VI) can be bioreduced to Cr(III) in bioreactors. Additionally, the microbial activity and electron transfer properties in the Mn redox system were studied under varying Cr(VI) concentrations. High-throughput data revealed that high Cr(VI) concentrations significantly impacted microbial community diversity, while <em>Aromatoleu</em> and <em>Zoogloea</em> consistently remaining the dominant species in the bioreactor. KEGG database analysis showed that appropriately increasing C/N promoted the expression of genes related to nitrification and Mn redox cycling. This study provides novel perspectives on the application of the Mnammox coupled MnOD process driven by the Mn redox cycle for treating NH₄⁺-N and Cr(VI) co-contaminated industrial wastewater.</div></div>","PeriodicalId":443,"journal":{"name":"Water Research","volume":"281 ","pages":"Article 123713"},"PeriodicalIF":11.4,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143862692","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":"Environmental impact of integrating decentralized urine treatment in the urban wastewater management system: A comparative life cycle assessment","authors":"Hanson Appiah-Twum, Tim Van Winckel, Julia Santolin, Jolien De Paepe, Stefanie Hellweg, Tove A. Larsen, Kai M. Udert, Siegfried E. Vlaeminck, Marc Spiller","doi":"10.1016/j.watres.2025.123630","DOIUrl":"https://doi.org/10.1016/j.watres.2025.123630","url":null,"abstract":"As municipal wastewater treatment regulations become more stringent, integrating source-separated urine treatment into centralized urban wastewater management offers a ‘hybrid’ solution. However, it is not clear how the environmental impacts of such hybrid systems compare to highly efficient centralized wastewater treatment plants (WWTPs) with low N₂O emissions and electricity use. In this study, a consequential life cycle assessment was used to compare the environmental impact of three urine separation hybrid wastewater treatment systems – which combine decentralized urine treatment with a highly efficient central WWTP– to a centralized WWTP treating mixed wastewater (baseline). The studied urine treatment systems include partial nitrification &amp; distillation, struvite precipitation &amp; stripping/scrubbing, and partial nitritation/anammox. Additionally, the environmental impact of urine pre-treatment by calcium hydroxide and electrochemical alkalinization methods on the partial nitrification &amp; distillation system was evaluated. The results show that all hybrid scenarios have a lower environmental impact in the freshwater ecotoxicity, marine toxicity, freshwater eutrophication and marine eutrophication categories compared to the baseline. However, all hybrid scenarios resulted in higher impacts on global warming compared to the baseline, with direct N₂O emissions being a key variable. Additionally, it was identified that urine alkalinization increased the environmental impact of the treatment system in 7 out of the 10 impact categories. A Pareto frontier analysis was developed to guide decision makers on where hybrid solutions could be used as a strategy to reduce global warming impacts of conventional WWTPs. Using N₂O emission factors of 75 WWTPs, 87% of centralized WWTPs had lower global warming impact compared to partial nitrification &amp; distillation, and 91% compared to partial nitritation/anammox hybrid solutions. However, at energy demands of 1 kWh/PE and 1.5 kWh/PE, both hybrid solutions showed lower global warming impact than all the studied WWTPs. The study highlights the potential of hybrid wastewater treatment solutions as a strategy to reduce global warming impacts in WWTPs with high N₂O emissions and electricity use as well as a mean to reduce marine eutrophication (i.e. nitrogen pollution).","PeriodicalId":443,"journal":{"name":"Water Research","volume":"35 1","pages":""},"PeriodicalIF":12.8,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143866571","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":"AHL-Mediated Quorum Sensing Drives Microbial Community Succession and Metabolic Pathway in Algal-Bacterial Biofilm System","authors":"Zuocheng Liu, Ting Zeng, Jinlong Wang, Zongping Wang, Daotong Zhao, Junchi Wei, Yongzhen Peng, Lei Miao","doi":"10.1016/j.watres.2025.123702","DOIUrl":"https://doi.org/10.1016/j.watres.2025.123702","url":null,"abstract":"Microalgae, ammonia-oxidizing bacteria (AOB), and anaerobic ammonium-oxidizing bacteria (AnAOB) have been proven to form an integrated algal-bacterial biofilm system with over 93% of total nitrogen removal. Compared to conventional nitrification-denitrification process, this system operated without additional organic carbon or aeration. In order to understand the interaction mechanisms between bacteria and algae, this study investigated microbial community succession, the changes in metabolic pathways and the potential role of acyl-homoserine lactone (AHL)-mediated quorum sensing (QS) during the formation of the algae/partial nitrification/anammox biofilm system. Within this algal-bacterial symbiotic biofilm, the dominant genera identified were <em>Candidatus</em>_Brocadia (AnAOB), <em>Nitrosomonas</em> (AOB), and <em>Geitlerinema</em> (microalgae), with relative abundances of 13.86%, 6.37%, and 2.88%, respectively. Compared with the first two stages, the abundance of genes related to nitrogen metabolism pathways (anaerobic ammonium oxidation, denitrification, and ammonia assimilation) increased, indicating enhanced nitrogen transformation capacity in the algal-bacterial symbiotic stage. Co-occurrence network analysis also revealed enhanced microbial interactions, with increased negative correlations (from 36.07% to 39.38%), high average standard betweenness centrality (from 0.193 to 0.304), and reduced community vulnerability (from 0.037 to 0.028), contributing to biofilm stability and resilience. The variations in AHLs provided direct evidence for more frequent interspecies communication, facilitating the ecological reconfiguration in the biofilm. Overall, the close synergistic relationship between microalgae and bacteria supports stable biofilm development and high nitrogen removal efficiency.","PeriodicalId":443,"journal":{"name":"Water Research","volume":"11 10 1","pages":""},"PeriodicalIF":12.8,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143858134","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":"Efficient remediation and synchronous recovery of uranium by phosphate-functionalized magnetic carbon-based flow electrode capacitive deionization","authors":"De Wang ,&nbsp;Jing Wang ,&nbsp;Di Zhang ,&nbsp;Jiaxing Li","doi":"10.1016/j.watres.2025.123707","DOIUrl":"10.1016/j.watres.2025.123707","url":null,"abstract":"<div><div>Through the design of flow electrodes, flow electrode capacitive deionization (FCDI) enables the efficient remediation of uranium-contaminated water to meet World Health Organization (WHO) standards (uranium ≤ 30 ppb), while concurrently facilitating the recovery of uranium from the flow electrode slurry. In this work, the phosphate-functionalized magnetic carbon-based flow electrode (OMPAC) was synthesized by simply co-precipitation and oxygen plasma treatment. The enhanced conductivity of OMPAC accelerated the efficient remediation of surface water contaminated with multiple nuclides, due to the improved charge-transfer capability facilitated by the introduced magnetic particles (Fe, Fe₃O₄, Fe₃C) and heteroatoms (O, P). The uranium in feed solution was selectively adsorbed by OMPAC in flow electrode slurry, benefiting from the multiple strong sorption interactions between U(VI) and C=O/P=O/P–O groups, as well as the redox reactions between U(VI) and Fe (0/II). After four batch cycles, the average uranium removal rate by OMPAC was maintained at 97.84 %, while the recovery rate of uranium from OMPAC reached 78.2 %, demonstrating the excellent long-term performance and synchronous uranium recovery capability in FCDI. This study provides feasibility guidance for the remediation of radioactive pollution and the strategic reuse of resources via the FCDI technology.</div></div>","PeriodicalId":443,"journal":{"name":"Water Research","volume":"281 ","pages":"Article 123707"},"PeriodicalIF":11.4,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143862724","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":"Characterisation of polysaccharide from anammox granular sludge and potential application in hydrogel preparation","authors":"Jie Liu, Yang Liu, Zi Zhang, Yangfan Deng, Guanghao Chen","doi":"10.1016/j.watres.2025.123710","DOIUrl":"https://doi.org/10.1016/j.watres.2025.123710","url":null,"abstract":"Microorganisms capable of anaerobic ammonia oxidation (anammox), or the conversion of nitrite and ammonium to dinitrogen, tend to aggregate and form a granular sludge in anammox reactors. This anammox granular sludge is a potential source of polysaccharides due to its richly diverse microbial community and abundant polymers. In this study, anammox polysaccharide (APS) was extracted from anammox granular sludge, and its potential to form hydrogels with alginate was investigated. The yield of APS was 9.91% ± 0.12%. The three main monosaccharides in APS were glucose (60.63% ± 3.45%), glucuronic acid (13.81% ± 0.31%), and rhamnose (18.88% ± 0.22%). The antioxidant potential of APS was evaluated through three antioxidant assays, which revealed significant antioxidant benefits at APS concentrations between 100 and 500 mg/L. Furthermore, L929 mouse fibroblasts exhibited high survival rates (&gt;85%) under different APS concentrations (1–50 μg/mL), indicating the good biological compatibility of APS. A series of hydrogels were prepared by mixing alginate with APS in different ratios (10:0, 9:1, 8:2, 7:3, and 6:4). The swelling ability of the prepared hydrogels in simulated gastric fluid varied between 1.4 and 2.0. In contrast, the swelling ability increased significantly to 10.37 ± 0.01 in simulated intestinal fluid when the ratio of alginate to APS in the hydrogel was 8:2. X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy were also used to analyse the functional groups and specific chemical bonds in the hydrogels. Subsequent loading experiments using bovine serum albumin (BSA) demonstrated that an alginate:APS ratio of 8:2 exhibited the highest loading efficiency for BSA, reaching 80.59% ± 1.46%. As the quantity of APS was increased, the release of BSA into simulated gastric fluid was effectively inhibited, with an alginate:APS ratio of 6:4 resulting in the lowest release amount (0.023% in dry state, 0.11% in wet state). Overall, this study highlights the derivation of a valuable resource from anammox sludge and offers insights into its potential applications in drug delivery.","PeriodicalId":443,"journal":{"name":"Water Research","volume":"690 1","pages":""},"PeriodicalIF":12.8,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143862696","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":"Interaction of non-biodegradable particles and granular sludge in Nereda®—— from nanoparticles to microparticles","authors":"Zhaoxu Peng ,&nbsp;Antonella L. Piaggio ,&nbsp;Guilherme Lelis Giglio ,&nbsp;Sara Toja Ortega ,&nbsp;Mark C.M. van Loosdrecht ,&nbsp;Merle K. de Kreuk","doi":"10.1016/j.watres.2025.123698","DOIUrl":"10.1016/j.watres.2025.123698","url":null,"abstract":"<div><div>&gt;50 % of the organic matter in sewage consist of particulate chemical oxygen demand (pCOD). This study used 250 μm fluorescent microbeads, 130±58 μm microparticles and 100 nm nanobeads to simulate sewage particles, and investigated the fate of these particles under both plug flow feeding and aeration phases in an aerobic granular sludge (AGS) system. Filtration performance was dominantly influenced by the particle size rather than the upflow velocity (V_upflow). The microbeads exhibited 95±3 % filtration efficiency with obvious accumulation around the AGS bed bottom, even as slight fluidization started at the V_upflow of 5.0 m·h^-1. In contrast, the nanobeads filtration efficiency was significantly lower (43±6 %). During the aeration phase, the attachment efficiency increased with the decrease of particle size. The microbeads attachment efficiency variated between 39–49 %, whereas the microparticles and nanobeads achieved better attachment of 89.4–95.2 % and 98.8–99.3 %, respectively. Furthermore, aeration batch tests showed both nanobeads and the irregular microparticles attachment by AGS was strong, and the detach-attach of nanobeads/microparticles between different sized AGS was very limited duration aeration. This work provides insight into the fate of particles in AGS system. The optimal sludge treatment was also evaluated in the scope of this removal of non-biodegradable, and potentially harmful particles.</div></div>","PeriodicalId":443,"journal":{"name":"Water Research","volume":"281 ","pages":"Article 123698"},"PeriodicalIF":11.4,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143862698","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":"Bacterial community analysis of recreational beach waters reveals human fecal contamination and pathogenicity across varying field conditions","authors":"Dong Li ,&nbsp;Laurie C. Van De Werfhorst ,&nbsp;Rachel T. Noble ,&nbsp;Denene Blackwood ,&nbsp;Jared Ervin ,&nbsp;Brandon Steets ,&nbsp;Jen Smith ,&nbsp;Patricia A. Holden","doi":"10.1016/j.watres.2025.123697","DOIUrl":"10.1016/j.watres.2025.123697","url":null,"abstract":"<div><div>Assessing human fecal contamination of recreational beach waters is a public health challenge owing to multiple sources and environmental conditions affecting indicator, pathogen, and source marker relationships. Human fecal-associated markers, such as HF183, accurately indicate human waste, but reliance on individual markers risks false negative diagnoses, owing to marker source loading variations and attenuation. Bacterial community analysis is a data-dense approach that could improve the accuracy of human waste detection, but relatedness to actual human health hazards under complex coastal water conditions is unproven. Here, two Malibu and one Pacific Palisades, CA recreational beaches differing in urbanization and sewerage were studied over two years across varying seasonal rainfall, and beach berm, conditions. Fecal indicator bacteria (FIB), HF183, and human norovirus concentrations were quantified and related to bacterial community 16S rRNA gene sequences which were further analyzed for putative human pathogens and sewage proportions. All lower watersheds harbored human fecal sources, and surf zone contamination was enhanced by rainfall runoff with berm breaching, which intensified with urbanization. Notably, for sequenced surf zone waters sampled across all weather conditions (<em>n</em> = 36), sequence-based putative pathogen proportions correlated with qPCR HF183 concentrations (w/ and w/o PMA treatment; <em>p</em> = 0.0) and with human norovirus G1concentrations (<em>p</em> = 0.04) which also correlated with HF183 sequence abundance in bacterial communities (<em>p</em> = 0.02). Although human fecal sources appeared to vary seasonally and a range of physical conditions influenced surf zone fecal contamination, human fecal contamination and associated health hazard were reliably evidenced by bacterial community analysis in this study.</div></div>","PeriodicalId":443,"journal":{"name":"Water Research","volume":"281 ","pages":"Article 123697"},"PeriodicalIF":11.4,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143862695","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":"Machine learning-guided performance prediction of forward osmosis polymeric membranes for boron recovery","authors":"Meng Wang ,&nbsp;Zhanlin Ji ,&nbsp;Yingchao Dong","doi":"10.1016/j.watres.2025.123700","DOIUrl":"10.1016/j.watres.2025.123700","url":null,"abstract":"<div><div>Efficient recovery of boron is one of the crucial strategies of sustainably extracting valuable resource from water. It however still remains a key technological challenge to efficiently predict boron recovery from unconventional water resources such as underground water, geothermal water and seawater, which are still few concerned in open literature. To effectively address this issue, herein we propose an efficient strategy to precisely predict boron recovery performance and then explore mechanism in forward osmosis process via advanced machine learning techniques with better model performance. Specifically, to explore the complex relationships among various boron recovery factors, we compare different advanced machine learning regression models to provide valuable insights into how these key factors impact system performance. We find that three key driving factors (i.e., pH, boron concentration, and membrane orientation) significantly affect boron recovery performance in the forward osmosis process. The best prediction accuracy with a high r-square (R², 95.4 %) is achieved via the XGBoost model combined with the particle swarm optimization algorithm, demonstrating its remarkable ability for precise boron recovery prediction. By employing this hybrid model to optimize the search space, the overall performance of forward osmosis system was significantly enhanced, with a predicted boron rejection rate as high as 98.28 %, outperforming the reported values. Our work demonstrates the powerful potential of advanced machine learning for efficiently predicting boron recovery for water quality improvement and resource recovery applications.</div></div>","PeriodicalId":443,"journal":{"name":"Water Research","volume":"281 ","pages":"Article 123700"},"PeriodicalIF":11.4,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143858135","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":"Removal of Nickel-Citrate by KOH-Modified Arundo donax L. Biochar: Critical Role of Persistent Free Radicals","authors":"Wei Liu ,&nbsp;Xiaomin Li ,&nbsp;Xiaolong Yang ,&nbsp;Zhenglin Chen ,&nbsp;Shu Liu ,&nbsp;Wenhong Fan","doi":"10.1016/j.watres.2025.123652","DOIUrl":"10.1016/j.watres.2025.123652","url":null,"abstract":"<div><div>Removal of heavy metal complexes (HMCs) from wastewater poses significant challenges to waste water treatment due to the inherent stability of these compounds. In this study, KOH modified <em>Arundo donax</em> L. leaves biochar was developed, which demonstrated a remarkable capacity for nickel-citrate (Ni-Cit) removal. The results found that the modified biochar with a KOH-to-biomass ratio of 1:1 (1KBC) showed over 500-fold increase in specific surface area compared to the original biochar, along with enhanced surface functional groups and persistent free radicals (PFRs). 99.2 % of nickel was removed from 50 mg/L Ni-Cit with 1 g/L of 1KBC in 4 h. It also demonstrated exceptional potential in continuous treatment. LC-MS, EPR analysis, and DFT calculations revealed that the PFRs on the biochar surface played critical role for the Ni-Cit removal. Reactive oxygen species (ROS) initiated by PFRs, especially O₂^•⁻, targeted the Ni-O coordination bonds, resulting in the decomplexation of Ni-Cit, while •OH and ¹O₂ facilitate the decarboxylation of the citrate ligand. The released Ni was then adsorbed onto the biochar. It indicated that the 1KBC removed Ni-Cit in one-step process with combined oxidation and adsorption. This research offers a promising technique for the efficient decomplexation and recovery of HMCs.</div></div>","PeriodicalId":443,"journal":{"name":"Water Research","volume":"281 ","pages":"Article 123652"},"PeriodicalIF":11.4,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143856114","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}