Water Cycle最新文献

{"title":"A rotating magnetic field propelled photocatalytic Fe3O4/g-C3N4 microrobot for degrading phenol and methylene blue: kinetics, mechanisms, and effect of water matrices","authors":"Luhui Xu ,&nbsp;Jianxin Zhang ,&nbsp;Jiani Zhang ,&nbsp;Yanping Zhang ,&nbsp;Hong Liu ,&nbsp;Ning Ding","doi":"10.1016/j.watcyc.2025.08.003","DOIUrl":"10.1016/j.watcyc.2025.08.003","url":null,"abstract":"<div><div>Graphitic carbon nitride (g-C₃N₄) has attracted widespread attention in the photocatalytic degradation of pollutants due to its unique thermal and physicochemical properties, whereas the low photocatalytic efficiency and difficulties in recycling limit its use. To improve the photodegradation of phenol and methylene blue in water, a new rotating magnetic field (RMF) propelled photocatalytic Fe₃O₄/g-C₃N₄ (FC) microrobot system has been created. The results demonstrated that the integration of RMF significantly enhanced the photocatalytic degradation of phenol and methylene blue by the Fe₃O₄/g-C₃N₄ microrobot. Under conditions of 1 g/L catalyst dosage and 2 A RMF excitation current, the Fe₃O₄/g-C₃N₄ microrobot with 20 % (w/w) Fe₃O₄ content (FC20) exhibited the highest photocatalytic activity, achieving 92.8 % degradation of phenol and &gt;99.9 % degradation of methylene blue within 300 min. Furthermore, FC20 demonstrated excellent reusability, maintaining high degradation efficiency after four consecutive cycles. Factors such as magnetic induction, photocatalyst dosage, and pH were found to influence the degradation efficiency of phenol and methylene blue by Fe₃O₄/g-C₃N₄ microrobots. Additionally, the effects of inorganic ions and water matrices on the degradation of phenol and methylene blue were investigated. By studying the degradation mechanisms, it was revealed that the order of influence of reactive species during the photodegradation process was: h⁺&gt;·O₂⁻&gt;·OH. In conclusion, the combined FC-RMF system has great potential for improving the removal of phenol and methylene blue pollutants from water.</div></div>","PeriodicalId":34143,"journal":{"name":"Water Cycle","volume":"7 ","pages":"Pages 128-138"},"PeriodicalIF":8.7,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145157769","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":"Algal growth potential based nitrogen and phosphorus criteria for bloom control","authors":"Jun-Han Liu ,&nbsp;Yun Lu ,&nbsp;Guo-Hua Dao ,&nbsp;Sheng-Nan Wang ,&nbsp;Ke-Ying Song ,&nbsp;Hong-Ying Hu","doi":"10.1016/j.watcyc.2025.10.004","DOIUrl":"10.1016/j.watcyc.2025.10.004","url":null,"abstract":"<div><div>High concentrations of nitrogen (N) and phosphorus (P) in aquatic systems can readily induce eutrophication, posing significant ecological and human health risks. Establishing scientifically sound N and P water quality criteria is therefore essential for effective water resource management and algal bloom mitigation. Current approaches to establishing lake nutrient criteria primarily rely on determining reference conditions, a method that faces practical limitations due to the pervasive pollution affecting most water bodies. To address this challenge, this study introduces an innovative methodology for deriving N and P criteria based on algal growth potential analysis, which establishes the theoretical minimum nutrient thresholds required for bloom formation.We selected and cultured twenty-three dominant algal species identified from documented bloom events to assess their growth potential. Under optimized cultivation conditions, we determined the maximum N and P yield coefficients for each species, from which we subsequently calculated species-specific N and P criteria based on predetermined bloom thresholds. Using species sensitivity distribution (SSD) analysis, we derived protective nutrient criteria corresponding to the 5^th percentile hazard concentration: 0.204 mg/L for N and 0.006 mg/L for P. These values are notably more stringent than those established in European and American guidelines, as well as previous Chinese studies. This study thus establishes a novel scientific framework for developing water quality standards, particularly applicable to urban lakes receiving reclaimed water with high N and P concentrations.</div></div>","PeriodicalId":34143,"journal":{"name":"Water Cycle","volume":"7 ","pages":"Pages 234-241"},"PeriodicalIF":8.7,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147394417","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":"Seasonal effects of rainfall on characteristics and environment response of dissolved organic matter (DOM) in urban rivers: insights from spectroscopy and machine learning","authors":"Kun Shi ,&nbsp;Jiafeng Zhang ,&nbsp;Yuting Zhao ,&nbsp;Shilei Zhou","doi":"10.1016/j.watcyc.2025.06.005","DOIUrl":"10.1016/j.watcyc.2025.06.005","url":null,"abstract":"<div><div>Urban river dissolved organic matter (DOM) is particularly vulnerable to monsoon climate rainfall impacts, but its mechanism remains unclear. The characteristics and environmental responses of DOM were analyzed by means of excitation-emission matrix combined with parallel factor analysis (EEM-PARAFAC) and machine learning. The results showed that the total nitrogen (TN) and chemical oxygen demand (COD) of downstream urban water (DUW) were significantly higher than those of upstream urban water (UUW) (P &lt; 0.01), and the rivers were generally in a mesotrophic state (TSI_M &gt; 30). Parallel factor analysis PARAFAC identified two humic-like components (C1 and C3) and one protein-like component (C2), with the variation order being C3 → C2 → C1. In different seasons, the abundance of protein-like components in UUW (29.78%–86.90%) was significantly higher than that in DUW (9.06%–66.86%), while in DUW, humic-like components dominated (33.12%–90.94%). DOM overall exhibited low humification and strong autochthonous characteristics (HIX &lt;4 and BIX &gt;1). Machine learning indicated that nitrogen concentration, pH, and temperature (T) were the key environmental factors affecting DOM components. The DOM network of UUW exhibited more complex topological properties. Path analysis showed that the properties of DOM in UUW in summer were most affected by its source, while in other spatiotemporal distribution states, Fe had the greatest impact on DOM properties. Our study highlights the complexity of DOM dynamic changes and their environmental significance under the background of rainfall, urbanization, and climate change, providing a scientific basis for urban river water quality management and protection strategies.</div></div>","PeriodicalId":34143,"journal":{"name":"Water Cycle","volume":"7 ","pages":"Pages 57-67"},"PeriodicalIF":8.7,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144756829","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 sulfur-autotrophic bacterial-algal synergistic system for enhanced nitrogen and phosphorus removal","authors":"Xintong Feng ,&nbsp;Jiquan Yin ,&nbsp;Ganlu Zhu ,&nbsp;Ning Guo ,&nbsp;Zhaoliang Zhu","doi":"10.1016/j.watcyc.2025.08.001","DOIUrl":"10.1016/j.watcyc.2025.08.001","url":null,"abstract":"<div><div>To address the limitations of traditional bacteria–algae symbiotic systems in treating low C/N wastewater—specifically, the high demand for external carbon sources and stringent aerobic conditions. This study constructed and investigated a novel sulfur-based autotrophic bacteria–algae synergistic system (BAS) aimed at achieving efficient and low-energy nitrogen and phosphorus removal. By optimizing operational parameters, the study systematically evaluated pollutant removal performance and operational stability and further elucidated the underlying mechanisms through microbial community structure analysis. The results showed that under conditions without external organic carbon input and aeration, the BAS system achieved NO₃⁻-N and TP removal efficiencies of 92 %–98.6 % and 60 %–65 %, respectively. The extracellular polymeric substances (EPS) content significantly increased; <em>Chlorella</em> exhibited robust growth with minimal biomass loss, and sludge flocculation performance was enhanced, enabling effective adsorption of byproducts such as SO₄²⁻. Dominant genera such as <em>Thiobacillus</em>, <em>Sulfurimonas</em>, and <em>Ferritrophicum</em> were further enriched during the stable operation of the system. Driven by light-dark cycle regulation, the system achieved temporally coupled, high-efficiency nitrogen and phosphorus removal through bacteria–algae cooperation, effectively overcoming the carbon limitation bottleneck of traditional systems under low C/N conditions. This provides a novel approach for developing energy-efficient biological wastewater treatment technologies.</div></div>","PeriodicalId":34143,"journal":{"name":"Water Cycle","volume":"7 ","pages":"Pages 181-191"},"PeriodicalIF":8.7,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145219562","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":"Assessing the spatiotemporal dynamics of algal communities in urban reservoirs: Influence of reservoir characteristics and river-reservoir connectivity","authors":"Kai He ,&nbsp;Yingying Lin ,&nbsp;Jizhou Cao ,&nbsp;Xinrui Lin ,&nbsp;Bingjun Liu ,&nbsp;Qidong Yin ,&nbsp;Xinfeng Zhao ,&nbsp;Aimin Hao ,&nbsp;Yun Zhang ,&nbsp;Bing Yang","doi":"10.1016/j.watcyc.2025.08.002","DOIUrl":"10.1016/j.watcyc.2025.08.002","url":null,"abstract":"<div><div>Algae in the lake-reservoir system of Guangdong-Hong Kong-Macao Greater Bay Area have important impacts on the regional water supply, but their dynamic characteristics and driving mechanisms have not been clarified. In this study, we systematically analyzed the influence mechanisms of water quality and hydrodynamic factors on algal proliferation in four interconnected reservoirs in Zhuhai City through continuous monitoring data from 2019 to 2022. The study first revealed the evolution of environmental parameters and algal communities based on seasonal scales: the analysis of multiple water-quality and hydrodynamic variables revealed that the hydrological conditions in the wet season were more favorable for algal proliferation, and the four reservoirs showed differential community succession paths and spatial and temporal differences in diversity. In order to further analyze the causes of algal differences among reservoirs, this paper used principal component analysis (PCA), Mantel test and NMDS methods to clarify that river-reservoir connectivity was the main driving factor affecting them. During connected periods, algal community variation was associated mainly with chemical oxygen demand (CODCr), hydraulic retention time (HRT), discharge volume, and dissolved oxygen (DO), whereas during disconnected periods it was associated mainly with pH, total phosphorus (TP), comprehensive trophic level index (TLI), and reservoir capacity. These associations suggest that connectivity-dependent hydrodynamic and water-quality conditions likely shaped algal community composition. This study reveals the key driving factors of algal dynamics in reservoirs in the Guangdong-Hong Kong-Macao Greater Bay Area, and provides a scientific basis for the ecological risk management of cross-regional water transfer systems.</div></div>","PeriodicalId":34143,"journal":{"name":"Water Cycle","volume":"7 ","pages":"Pages 573-582"},"PeriodicalIF":8.7,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148231169","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":"Water ecological health assessment based on environmental nucleic acids: New directions and frontier applications","authors":"Jirong Hu,&nbsp;Zimeng Gao,&nbsp;Yun Lu","doi":"10.1016/j.watcyc.2026.05.001","DOIUrl":"10.1016/j.watcyc.2026.05.001","url":null,"abstract":"<div><div>In recent years, with the development of high-throughput sequencing technology and molecular biology technologies, environmental nucleic acid (eDNA, eRNA) has become an important way to evaluate ecological health. Although many reviews have focused on the application of eDNA/eRNA in biodiversity assessment, this paper attempts to explore how to apply new methods of analyzing eDNA/eRNA in assessing the health status of aquatic ecosystems. This review summarizes four main progress: high frequency automatic sampling and monitoring, application of unsupervised machine learning in predicting ecosystem conditions, population genetic analysis, non-invasive ecological toxicological monitoring. In the future, standard technical protocols for eDNA/eRNA will continue to be refined, a multidimensional database integrating genomic, transcriptomic and epigenetic information will be established, which can provide a non-invasive, quick, portable, information-rich way for checking if the water environment is healthy, and give the early warnings of pollution risk.</div></div>","PeriodicalId":34143,"journal":{"name":"Water Cycle","volume":"7 ","pages":"Pages 644-650"},"PeriodicalIF":7.9,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148854004","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":"A multi-criteria approach to fluvial flood vulnerability assessment: A case study of lower Manya Krobo municipality","authors":"Aaron Tettey Tetteh ,&nbsp;Serah Kahuri ,&nbsp;Lily Lisa Yevugah ,&nbsp;Abdul-Wadood Moomen ,&nbsp;Paul Adjei Kwakwa ,&nbsp;Issaka Yakubu","doi":"10.1016/j.watcyc.2025.06.001","DOIUrl":"10.1016/j.watcyc.2025.06.001","url":null,"abstract":"<div><div>Fluvial flooding predominantly occurs in areas near large water bodies. This study utilized an integrated approach combining Geographic Information System (GIS), Remote Sensing and the Analytic Hierarchy Process (AHP) to assess fluvial flood vulnerability in the Lower Manya Krobo Municipality, Ghana. Ten causative factors of flooding were derived from remotely sensed data and weighted using AHP. The model revealed that 9.19% of the municipality is in a very high-risk zone, and 26.76% is in a high-risk zone, with slope and elevation identified as the primary contributors to flooding. Notable towns and landmarks within the very high- and high-risk zones include parts of Kpong and Akuse, along with Obele M.A. Primary School, Modern Senior High School, and Presby and New Covenant Apostolic Churches. These findings highlight vulnerable areas and provide valuable data for disaster management agencies, such as the National Disaster Management Organization and the Volta River Authority, to enhance flood preparedness and mitigation efforts in the region.</div></div>","PeriodicalId":34143,"journal":{"name":"Water Cycle","volume":"7 ","pages":"Pages 68-82"},"PeriodicalIF":8.7,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144756830","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":"Fe-Cu-loaded γ-Al2O3 as an efficient heterogeneous Fenton catalyst for the advanced treatment of petrochemical wastewater","authors":"Shiqi Jiang ,&nbsp;Changyong Wu ,&nbsp;Qi Huang ,&nbsp;Yin Yu ,&nbsp;Peijian Zhang ,&nbsp;Chenjie Wang ,&nbsp;Xiyan Ou ,&nbsp;Min Xu","doi":"10.1016/j.watcyc.2025.06.006","DOIUrl":"10.1016/j.watcyc.2025.06.006","url":null,"abstract":"<div><div>A novel Fe-Cu/γ-Al₂O₃ heterogeneous Fenton catalyst was developed for the degradation of real petrochemical secondary effluent using H₂O₂ under near-neutral pH conditions (6–8). This approach addresses key limitations of traditional Fenton systems, including their narrow pH range and generation of iron sludge. No sludge formation was detected, and Fe/Cu leaching remained below 1 mg/L after nine consecutive reuse cycles, confirming the catalyst's stability and reusability. The catalyst was synthesized via impregnation and calcination, with preparation parameters optimized using a one-factor-at-a-time method. Under optimal conditions (Fe: 0.28 mol/L; Cu: 0.20 mol/L; 500 °C; 7 h), 50.15% TOC removal was achieved using 20 g catalyst and 13.73 mmol/L H₂O₂. Characterization techniques (SEM, BET, XRD, XPS) confirmed the structural features, while EPR and quenching experiments revealed that ·OH and HO₂⁻ were the dominant reactive species. The Fe(III)/Fe(II) and Cu(II)/Cu(I) redox pairs on the catalyst surface were identified as active sites for H₂O₂ activation. This study demonstrates a robust, sludge-free Fenton-like system with practical potential for advanced petrochemical wastewater treatment.</div></div>","PeriodicalId":34143,"journal":{"name":"Water Cycle","volume":"7 ","pages":"Pages 19-30"},"PeriodicalIF":8.7,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144749638","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":"How cascade dams reshape river thermal seasons: Satellite tracking of delayed spawning windows and range contractions in the Yangtze","authors":"Xiaoyu Liu ,&nbsp;Xinyuan Peng ,&nbsp;Manjie Li ,&nbsp;Zi Wu ,&nbsp;Lu Chang","doi":"10.1016/j.watcyc.2025.07.003","DOIUrl":"10.1016/j.watcyc.2025.07.003","url":null,"abstract":"<div><div>The construction of cascade hydropower stations along the Yangtze River has fundamentally altered its natural thermal regime, with significant implications for aquatic ecosystems. This study integrates multi-source remote sensing data (Landsat 5/7/8 TIR), NCEP/NCAR reanalysis datasets, and long-term hydrological observations (1988–2021) to systematically evaluate the spatiotemporal impacts of major reservoirs on water temperature dynamics. Results reveal that cascade impoundment has amplified seasonal thermal fluctuations, with spring low-temperature discharges reducing downstream water temperatures by 0.4–1.8 °C and winter warm-water releases increasing temperatures by 1.2–2.2 °C. The timing of annual minimum water temperatures has been delayed by 35–42 days, disrupting critical life-cycle events for endemic fish species. Comparative analysis demonstrates that after impoundment, the temperature conditions often exceed the spawning threshold of protected species such as the Chinese sturgeon (16–20 °C). The successful spawning migration has decreased by 62%, and only 28% of the historical spawning grounds maintain appropriate temperature conditions. Thermophilic species have expanded their range upstream by 120–150 km, while cold - adapted species have suffered a range contraction of 45–60%. The study emphasizes the combined effects of multi - reservoir operations, indicating that later - built dams extend the thermal impact upstream. Moreover, in the warmer downstream river sections, the decomposition rate of organic matter has accelerated by 35–50%, significantly altering the nutrient cycling dynamics. These findings provide critical insights for optimizing ecological dispatching strategies and underscore the need for integrated management approaches that balance hydropower generation with ecosystem conservation in large river basins. The methodological framework combining remote sensing with ecological thresholds offers a transferable approach for assessing dam impacts in other regulated river systems worldwide.</div></div>","PeriodicalId":34143,"journal":{"name":"Water Cycle","volume":"7 ","pages":"Pages 120-127"},"PeriodicalIF":8.7,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144866224","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":"Water reuse standards promote water cycle—starting from the ISO 20761 water reuse safety evaluation standard","authors":"Hong-Ying Hu","doi":"10.1016/j.watcyc.2025.11.003","DOIUrl":"10.1016/j.watcyc.2025.11.003","url":null,"abstract":"","PeriodicalId":34143,"journal":{"name":"Water Cycle","volume":"7 ","pages":"Pages 192-193"},"PeriodicalIF":8.7,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145614263","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}