Water Cycle最新文献

{"title":"Treatment of low C/N wastewater containing phthalates in algal pond-constructed wetlands: Roles of extracellular polymeric substances and microbiome","authors":"Xinting Fan ,&nbsp;Hua Li ,&nbsp;Jialan Yu ,&nbsp;Ming Li ,&nbsp;Xin Zhao ,&nbsp;Haiming Wu","doi":"10.1016/j.watcyc.2026.03.003","DOIUrl":"10.1016/j.watcyc.2026.03.003","url":null,"abstract":"<div><div>Carbon source deficiency is the crucial factor constraining conventional biological nitrogen removal in low C/N wastewater. Therefore, this study investigated nutrients and dimethyl phthalate (DMP) removal and mechanisms in an algal pond-constructed wetland system treating wastewater at different low C/N ratio. The findings indicated that the system exhibited optimal comprehensive treatment performance at a C/N ratio of 5. Under this condition, the removal efficiencies of ammonia nitrogen, total nitrogen and DMP reached 98.5 %, 56.8 % and 78.0 %, respectively, while nitrous oxide emissions were significantly reduced. <em>Scenedesmus obliquus</em> exhibited good growth. Meanwhile, extracellular polymeric substances (EPS) secreted by microorganisms were mainly soluble EPS, which served as a slow-release carbon source to supplement the electron donors required for denitrification and enhanced DMP biodegradation. Although an elevated C/N ratio reduced microbial community biodiversity and abundance, it significantly enhanced the relative abundance of functional microbes related to nitrogen transformation. Notably, the levels of denitrification functional genes (<em>norB</em>, <em>nosZ, nirK</em>, <em>nirS</em>) all improved, indicating enhanced genetic and metabolic potential for denitrification. These findings indicate moderately optimizing the influent C/N ratio can effectively and synergistically remove multiple pollutants and reduce greenhouse gas emissions in the integrated system, offering a theoretical foundation for the co-treatment and ecological remediation of multiple pollutants in low C/N wastewater.</div></div>","PeriodicalId":34143,"journal":{"name":"Water Cycle","volume":"7 ","pages":"Pages 516-525"},"PeriodicalIF":8.7,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147991481","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A comprehensive bibliometric and metadata analysis review of flash flood and rainfall studies in the Arabian Peninsula","authors":"Abdalmonem Alkhawaga ,&nbsp;Mohamed M. Mohamed","doi":"10.1016/j.watcyc.2025.10.005","DOIUrl":"10.1016/j.watcyc.2025.10.005","url":null,"abstract":"<div><div>Flash floods are among the most destructive natural disasters, posing risks to an increasing number of areas because of the growing incidence of extreme rainfall events. Considerable interest has been drawn to the modeling of flash floods in the arid region of the Arabian Peninsula (AP). This work provides comprehensive bibliometric and metadata analyses of studies on flash floods and rainfall in the AP, clarifying the related trends and future research directions. Different bibliometric software tools are used to analyze 289 publications indexed in Scopus and published in 1975–2024, with the results providing an overview of key metrics such as the number of publications over time, citation rates, keyword analysis, institutional cooperation, and author contributions. Metadata analysis reveals various subfields of flash floods, highlighting key findings and identifying gaps to be addressed in future studies. A notable increase in the number of publications since approximately 2010 is observed, with most studies concentrating on Saudi Arabia. The key identified research gaps include the need for rainfall analysis based on minimum interevent time to improve the performance of hydrological analysis. Moreover, we underscore the importance of the economic and life-cycle assessments of mitigation measures and dam safety re-evaluation based on updated hydrological data and urban development trends, outlining further gaps to support future research and sustainable flood management in the AP. Although this review focuses on the AP, it serves as a valuable guide for researchers studying flash floods in other arid and semiarid regions.</div></div>","PeriodicalId":34143,"journal":{"name":"Water Cycle","volume":"7 ","pages":"Pages 242-266"},"PeriodicalIF":8.7,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147448960","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exogenous γ-aminobutyric acid alleviates selenite stress and enhances organic selenium and energy-storage compound accumulation in Tribonema minus","authors":"Feifei Wang ,&nbsp;Rundong Yang ,&nbsp;Yuanhong Li ,&nbsp;Shuyi Li ,&nbsp;Shuiyuan Cheng ,&nbsp;Zhenzhou Zhu","doi":"10.1016/j.watcyc.2025.11.004","DOIUrl":"10.1016/j.watcyc.2025.11.004","url":null,"abstract":"<div><div><em>Tribonema minus</em>, a filamentous microalga, has been shown to effectively remove selenite while accumulating biomass enriched with organic selenium and carbohydrates. However, elevated selenite concentrations markedly inhibit its growth. This study evaluated the potential of γ-aminobutyric acid (GABA; 0.1–10 mg/L) to alleviate selenite-induced stress and enhance the accumulation of value-added products. Supplementation with 10 mg/L GABA yielded optimal results, increasing biomass by 44.72 % and enhancing carbohydrate and lipid productivities by 32.23 % and 71.44 %, respectively. These enhancements were attributed to GABA-mediated activation of antioxidant defences, increased chlorophyll <em>a</em> content, and redirection of carbon flux. GABA also mitigated selenite toxicity by decreasing the apparent selenium removal per unit biomass in the medium and shifting intracellular selenium speciation towards less toxic forms. Within the first six days, expression of two genes involved in toxic selenoprotein synthesis (<em>OsCS</em> and <em>OsSBP1</em>) was significantly downregulated, accompanied by the formation of inert selenium polysaccharides. Meanwhile, selenium volatilisation was suppressed, resulting in a net increase in intracellular selenium accumulation. By day 9, organic selenium productivity rose by 30.75 %, predominantly in the form of selenomethionine. Although biomass-normalised selenium removal declined, the elevated biomass maintained a high selenium removal efficiency of 93.78 %. These findings provide the first mechanistic evidence for GABA's role in alleviating selenite stress and highlight its potential to improve selenium tolerance and bioremediation efficiency of <em>T. minus</em> in selenium-laden wastewater.</div></div>","PeriodicalId":34143,"journal":{"name":"Water Cycle","volume":"7 ","pages":"Pages 292-301"},"PeriodicalIF":8.7,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147448964","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A hybrid approach for exploring the spatiotemporal patterns of precipitation in Sudan: Insights from neural network clustering and Fourier-wavelet transform analysis","authors":"Csaba Ilyés ,&nbsp;Musaab A.A. Mohammed ,&nbsp;Norbert P. Szabó ,&nbsp;Péter Szűcs","doi":"10.1016/j.watcyc.2025.07.004","DOIUrl":"10.1016/j.watcyc.2025.07.004","url":null,"abstract":"<div><div>Understanding the spatiotemporal variation of precipitation is critical for climate modeling, resource management, and agricultural planning. This study employs self-organizing maps (SOM), discrete Fourier transform (DFT), and wavelet transform (WT) to analyze monthly precipitation data from 80 monitoring stations across Sudan from 2010 to 2019. Initially, cluster analysis identified six distinct precipitation clusters that align with the north-south precipitation gradient, ranging from arid conditions in the northern desert to tropical rainfall in the south. SOM analysis revealed distinct spatial and temporal precipitation patterns, with notable variations between nodes representing climatic zones, such as arid deserts, semi-arid areas, and tropical rainfall zones. This analysis confirmed that central parts of Sudan serve as a transition between northern and southern climatic regimes. The spectral analysis using DFT identified dominant precipitation cycles across measurement points, including annual and semi-annual cycles, detected at all sites with the highest amplitudes. Cycles of 4 months, 3 months, and 2.5 months were also observed, with varying relative amplitudes across regions. Notably, a 60-month (5-year) cycle appeared at specific locations, potentially linked to the Quasi-Biennial Oscillation (QBO) and El Niño Southern Oscillation (ENSO). Complementary wavelet transformation results confirmed the dominance of annual and semi-annual cycles, although shorter cycles such as 2.5 months and 24 months were detected. The outcomes of this research provided a robust framework for understanding rainfall variability, enabling sustainable water resource management.</div></div>","PeriodicalId":34143,"journal":{"name":"Water Cycle","volume":"7 ","pages":"Pages 151-163"},"PeriodicalIF":8.7,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145219560","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of climate change impact on future flood in the Bagmati river basin, Nepal using CMIP6 climate projections and HEC-RAS modeling","authors":"Sushmita Malla (Doctor Course Student) ,&nbsp;Koichiro Ohgushi (Doctor of Engineering,Professor)","doi":"10.1016/j.watcyc.2025.08.004","DOIUrl":"10.1016/j.watcyc.2025.08.004","url":null,"abstract":"<div><div>The unpredictability of hydrological patterns attributed to climate change has led to significant alterations in weather patterns, precipitation irregularities, and temperature extremes. These changes have resulted in natural calamities, prompting an examination of the impact of climate change on evolving flood patterns. This study investigates the potential effects of projected future precipitation in the Bagmati River Basin, Nepal, on flood inundation extent during three different time periods in this century. Two General Circulation Models (GCMs) climate scenarios under the Coupled Model Inter-comparison Project Phase 6 (CMIP 6) framework were employed to project future conditions. The Hydrologic Engineering Center's River Analysis System (HEC-RAS) was utilized to simulate flood events and generate maps for these climate scenarios. The findings suggest that i) precipitation levels are anticipated to increase in both models under the Shared Socioeconomic Pathways (SSP) 2–4.5 and 5–8.5 scenarios, with the most pronounced increase projected between 2071 and 2100 under the EC-EARTH3 SSP5-8.5 scenario, indicating a 120% rise from the reference period, and ii) flood inundation areas are expected to expand relative to the simulated reference period, with the most extreme scenario under SSP5-8.5 forecasting potential inundation of 359 km² and 342 km² in the ACCESS-CM2 and EC-EARTH3 models, respectively. By examining these future scenarios, this study aims to enhance the understanding of the long-term impacts of climate change on flooding events and support the development of effective strategies for mitigation and adaptation. These findings are crucial for policymakers, urban planners, and disaster management professionals to prepare for and address the challenges posed by climate-induced flooding in the coming decades.</div></div>","PeriodicalId":34143,"journal":{"name":"Water Cycle","volume":"7 ","pages":"Pages 164-180"},"PeriodicalIF":8.7,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145219561","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"“A multi-method approach to groundwater potential assessment: Integrating remote sensing, GIS, and AHP in North Shoa zone, Ethiopia”","authors":"Eyosias Birhanu Alemu,&nbsp;Abebaw Belayneh Zelalem","doi":"10.1016/j.watcyc.2025.06.002","DOIUrl":"10.1016/j.watcyc.2025.06.002","url":null,"abstract":"<div><div>Groundwater is essential for human health, economic development, and ecosystem sustainability, particularly in water-scarce regions. In Ethiopia, it supplies over 70% of the national water demand, yet localized assessments remain limited. This study addresses this gap for the North Shewa Zone, where water scarcity is exacerbated by low rainfall, reliance on rain-fed agriculture, and rapid population growth. By integrating Geographic Information Systems (GIS), Remote Sensing (RS), and the Analytical Hierarchy Process (AHP), we developed a groundwater potential map using thematic layers such as geology, lineament density, land use/land cover, slope, rainfall, drainage density, and soil type. For validation, well location data were obtained from the Ministry of Water and Energy, and a three-month field survey (15 February – 15 May 2022)was conducted to verify well locations and directly measure water yields from 31 boreholes (1). Despite challenges such as incomplete historical water yield records and non-functional water meters, the results indicate that 0.5% (80.8 km²) of the study area has Very High groundwater potential, 24.7% (3994.5km²) High, 58.8% (9505.56 km²) Moderate, and 15.9% (2505.16 km²) Very Low (2). Validation through Receiver Operating Characteristic (ROC) curve and Area Under the Curve (AUC) analysis yielded an AUC of 0.89, demonstrating strong agreement with borehole yield data (3). This confirms that integrating Remote Sensing and GIS is highly effective for delineating groundwater potential zones. This study provides a cost-effective, scalable, and reliable method for groundwater assessment, offering actionable insights to improve irrigation and potable water supply in North Shewa Zone.</div></div>","PeriodicalId":34143,"journal":{"name":"Water Cycle","volume":"7 ","pages":"Pages 31-47"},"PeriodicalIF":8.7,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144756820","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Synthesis of granular algal-biomass-based catalysts for enhanced ozonation of wastewater","authors":"Yu-Tong Cai ,&nbsp;Yue Yuan ,&nbsp;Hai-Di Wang ,&nbsp;Fang Wang ,&nbsp;Si-Yi Liang ,&nbsp;Lu Zhao ,&nbsp;Yin Yu ,&nbsp;Chang-Yong Wu","doi":"10.1016/j.watcyc.2026.03.001","DOIUrl":"10.1016/j.watcyc.2026.03.001","url":null,"abstract":"<div><div>Catalysts are crucial for the catalytic ozonation treatment of refractory industrial wastewater. While carbon-based catalysts are considered as promising alternatives to metal-based ones, their practical application is severely hindered by costly heteroatom doping (e.g., N, P) and difficulty in separating and reusing their predominant powder forms. Algal biomass is a promising raw material for carbon-based catalyst, given its inherent nitrogen and phosphorus content, and wide availability from diverse sources such as algal bloom waste or industrial algal residues. Here, we report a novel strategy to synthesize granular carbon-alumina composite catalysts directly from algal biomass. The granular catalysts were fabricated via a single-step process involving mixing algae biomass with alumina, granulation, and thermal treatment in an inert atmosphere, which simultaneously induced the pyrolysis of algae and the sintering of alumina. The resulting granular catalyst exhibited excellent performance in catalytic ozonation, achieving removal rate of 97.3 % for oxalic acid in synthetic wastewater, and 63.9 % for COD in actual hypersaline industrial wastewater. This study provides a feasible technical pathway for fabricating granular algal-biomass-based catalysts, advancing the research and application of novel green algal-derived materials in catalytic ozonation.</div></div>","PeriodicalId":34143,"journal":{"name":"Water Cycle","volume":"7 ","pages":"Pages 490-495"},"PeriodicalIF":8.7,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147797812","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"In-situ ultrasonic treatment for effective clogging mitigation in sand filters","authors":"Huaqing Liu ,&nbsp;Chen Bai ,&nbsp;Jianbin Chen ,&nbsp;Jianqiao Qi ,&nbsp;Zhen Hu ,&nbsp;Xiaotong Shen ,&nbsp;Guang Yang ,&nbsp;Longlong Zhang ,&nbsp;Lian Zhang ,&nbsp;Jian Zhang","doi":"10.1016/j.watcyc.2026.02.003","DOIUrl":"10.1016/j.watcyc.2026.02.003","url":null,"abstract":"<div><div>Sand filtration systems are cornerstone technologies in water treatment, yet they frequently suffer from clogging due to particle and biofilm accumulation, compromising efficiency and escalating maintenance demands. Ultrasonic treatment has shown significant potential in mitigating the clogging of filtration systems; however, most existing studies have focused predominantly on its applications in ultrafiltration and microfiltration. The potential of ultrasonic treatment in sand filtration remains largely unexplored. This study investigates the effectiveness and underlying mechanisms of in situ ultrasonic treatment (20–40 kHz) for reducing substrate clogging in sand filters. Results indicate that intermittent continuous ultrasound application delays clogging progression, with the 40 kHz treatment at 60 kW/m² achieving the best performance. Conversely, pulsed treatment at 28 kHz and 60 kW/m² was most effective in restoring permeability in sand filters, due to an optimal balance of cavitation intensity and stability. Ultrasonic treatment promoted particle disaggregation, reduced aggregate size, altered surface charge, and oxidized organic matter, thereby enhancing filter permeability. The approach was particularly effective against clogging caused by inorganic particles and showed high performance in treating clogging influenced by organic matter. Intermittent continuous ultrasound outperformed pulsed treatments in systems with high organic content, attributed to enhanced release or degradation of organic compounds. However, filters clogged by large particles and high volatile solids content exhibited limited recovery, suggesting that ultrasonic treatment is more effective for clogging dominated by small, inorganic particles. These findings highlight ultrasound as a sustainable and effective strategy for mitigating clogging in sand filtration systems.</div></div>","PeriodicalId":34143,"journal":{"name":"Water Cycle","volume":"7 ","pages":"Pages 496-504"},"PeriodicalIF":8.7,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147797816","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Decoding a full-scale coupled treatment process for oxytetracycline production wastewater: Process performance, transformation pathways, and microbial community characteristics","authors":"Hong Liu,&nbsp;Tiantian Ren,&nbsp;Liangliang Shi,&nbsp;Shikang Zhou,&nbsp;Yongzhi Chen,&nbsp;Juan Ma,&nbsp;Hanpeng Yue","doi":"10.1016/j.watcyc.2026.04.003","DOIUrl":"10.1016/j.watcyc.2026.04.003","url":null,"abstract":"<div><div>Oxytetracycline (OTC), a widely used broad-spectrum antibiotic, generates wastewater containing extremely high concentrations of organic matter, ammonium nitrogen (NH₄⁺-N), and residual antibiotics, posing significant ecological and human health risks. A full-scale coupled treatment system integrating anaerobic fermentation (UASB), biological nitrogen and carbon removal, and advanced oxidation was operated for one year to treat oxytetracycline production wastewater, reducing OTC from 29.9–32.98 mg/L to 0.007–0.064 mg/L, corresponding to an overall removal efficiency of approximately 97.9%–99.98% across the entire treatment train. Based on three putative degradation pathways inferred from LC–MS signal evolution and literature comparison, OTC was ultimately transformed into low-toxicity small molecules, including C₄H₁₀O and C₄H₃O₂. The combined process effectively reduced COD and NH₄⁺-N from 10,726–8398 mg/L and 2354–1818 mg/L to 20–98 mg/L and 3–37 mg/L, respectively. Microbial community analysis revealed significant enrichment of nitrifying bacteria (<em>Nitrosomonas</em>), denitrifying bacteria (<em>Ottowia</em> and <em>OLB8</em>), and bacterial genera potentially involved in organic compound transformation (e.g., <em>Terrimonas</em> and <em>Thauera</em>), indicating their synergistic roles in nitrogen transformation and antibiotic degradation. Nitrite accumulation was frequently observed in the A/O process, suggesting the possible occurrence of partial nitrification under specific operational conditions, potentially associated with the suppression of nitrite-oxidizing bacteria (NOB). This observation suggests that the system may support partial nitrification–denitrification under suitable operational conditions. Furthermore, upgrading this system to AOA or AOAO configurations may represent a promising strategy for future wastewater treatment plants, enabling higher stability, process diversification, and energy-efficient operation, thereby providing a feasible and scalable solution for the advanced treatment and standard upgrading of oxytetracycline production wastewater.</div></div>","PeriodicalId":34143,"journal":{"name":"Water Cycle","volume":"7 ","pages":"Pages 632-643"},"PeriodicalIF":7.9,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148853998","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Revisiting the iron oxide layer in micron zero-valent iron for pollutant removal: High contribution of surface-adsorbed Fe(II) and initiated protons","authors":"Haoming Lu,&nbsp;Qinxue Wen,&nbsp;Heng Zhang,&nbsp;Bo Lai,&nbsp;Zhiqiang Chen,&nbsp;Jun Ma","doi":"10.1016/j.watcyc.2026.06.003","DOIUrl":"10.1016/j.watcyc.2026.06.003","url":null,"abstract":"<div><div>Surface modification is an effective strategy for mitigating surface passivation and enhancing the reactivity of zero-valent iron(ZVI). The increased reactivity of modified ZVI is considered to be primarily attributed to enhanced electron transfer capability and generation of highly reactive electron donors on the modified ZVI surface, whereas the role of protons is often overlooked. In this research, a mild and rapid method for preparing Fe₃O₄-loaded micron ZVI(mZVI) composite material was proposed and the proton-related mechanism of the iron oxide layer was further investigated. Trace sulfide ions(S²⁻) were introduced to modulate the redox intensity, enabling rapid preparation of Fe₃O₄-loaded mZVI composite material(r-Fe₃O₄/mZVI) via aerial oxidation of Fe²⁺. XRD, XPS, and FTIR analyses confirmed that the iron oxide layer loaded on r-Fe₃O₄/mZVI was primarily composed of magnetite. 500 mg/L <em>p</em>-nitrophenol (PNP) was completely removed within 25 min by using 5 g/L r-Fe₃O₄/mZVI at an initial pH of 3. Cyclic voltammetry, alcohol quenching, products identification, and ferrozine inhibition experiments confirmed that surface-adsorbed Fe(II) was the reactive species. Quantitative calculation based on electron and proton mass balance shows that in r-Fe₃O₄/mZVI reaction, the oxidation of surface-adsorbed Fe(II) on the iron oxide layer provided 94.17 % of the protons and up to 31.39 % of the electrons required for PNP removal. Mechanistic analysis revealed that the iron oxide layer suppressed electron transfer from mZVI but promoted the oxidation of surface-adsorbed Fe(II), thereby enhancing proton generation. The pre-loading an iron oxide layer on mZVI surface to enhance proton generation represented an effective strategy for promoting pollutant removal from mZVI reduction.</div></div>","PeriodicalId":34143,"journal":{"name":"Water Cycle","volume":"7 ","pages":"Pages 701-709"},"PeriodicalIF":7.9,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148994789","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}