Water Research最新文献_第6页

Thermal history influences the recovery of phototrophic biofilms exposed to agricultural run-off in intermittent rivers 热历史影响间歇性河流中暴露于农业径流的光养生物膜的恢复

IF 11.4 1区环境科学与生态学 Q1 ENGINEERING, ENVIRONMENTAL

Water Research

Pub Date : 2025-04-01 DOI: 10.1016/j.watres.2025.123580

Camille Courcoul, Joséphine Leflaive, Anne-Sophie Benoiston, Jessica Ferriol, Stéphanie Boulêtreau

The response of microbial communities to disturbances may be controlled by the past environmental conditions, through their legacy effect. In intermittent rivers, the fixed microorganisms, such as phototrophic biofilms, are exposed to variable environmental conditions, including changes in water chemistry, hydrodynamics and, in some cases water temperature. The latter may be particularly affected by the increasing frequency of summer heat waves. Our objective was therefore to assess the legacy effect of warming on phototrophic biofilms during a flow intermittency sequence. Our main hypotheses were that the thermal history of biofilms determines (i) the community trajectory after rewetting and (ii) its resistance and resilience to a new disturbance.

To test these hypotheses, we exposed phototrophic biofilms grown in the lab to a flow intermittency sequence (1 week no flow / 12 weeks no water) at two contrasted temperatures (22 °C and 32 °C). After rewetting (22 °C), some of the biofilms were exposed for 1 week to a new disturbance, i.e. a contaminant mimicking agricultural run-off (nitrate, copper, insecticide, herbicide, fungicide). The structure (pigments, elementary composition, extracellular polymeric substances, prokaryotic composition) and functioning (respiration, photosynthesis, functional diversity) of the biofilms were measured at the end of the contamination, and after 1 and 3 weeks of recovery without contaminant.

Our results unexpectedly show that one week after rewetting the “warmed” biofilms were less heterotrophic than the “non-warmed” biofilms. This effect was transitory, although the prokaryotic composition of the biofilms still diverged 4 weeks after rewetting. The legacy effect of warming was an increased sensitivity of the biofilms to the complex contaminant, especially at the highest concentrations. This legacy effect decreased with time for the general structure and functioning of the biofilms, but persisted for the prokaryotic composition. These findings highlight the importance of historical conditions, and particularly thermal history, in the ability of microbial communities to respond to disturbances.

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引用次数: 0

Applying side-stream gas recirculation to promote anaerobic digestion of food waste under ammonia stress: Overlooked impact of gaseous atmospheres on microorganisms

IF 11.4 1区环境科学与生态学 Q1 ENGINEERING, ENVIRONMENTAL

Water Research

Pub Date : 2025-03-31 DOI: 10.1016/j.watres.2025.123571

Linyan He , Jinze Li , Lizhan Tang , Yifei Wang , Xueyu Zhao , Keke Ding , Linji Xu , Li Gu , Shang Cheng , Yi yuan Wei

High ammonia concentrations can be toxic to microorganisms, leading to the accumulation of hydrogen (H₂) and acids in anaerobic digestion (AD) system. In this study, a side gas recycling strategy (SGR), coupled with a primary reactor and a small side-stream reactor, which recirculates biogas between primary reactor and side reactor was employed to mitigate ammonia inhibition. This approach enabled the mesophilic side-stream gas recirculation system (SMGR) and the thermophilic side-stream gas recirculation system (STGR) to ultimately withstand ammonia stress levels of 2.5 g/L and 3.5 g/L, respectively, while maintaining lower hydrogen partial pressures. In contrast, the control group experienced system failure at an ammonia concentration of 2 g/L. Enzyme activity, microbial community, and metaproteomic analysis indicated that the side reactor enriched microorganisms with strong hydrogen-utilizing capacity, while the primary reactor was enriched with Methanosaeta. Furthermore, key pathways related to propionate metabolism, ABC transporters, and methane production were enhanced in the primary reactor, along with increased ATPase activity. The activity of key enzymes involved in AD was also significantly enhanced. This study enhances the understanding of the impact of gas atmosphere control on the microbial ecology and metabolic characteristics of AD system, providing valuable insights and practical guidance for the development of Engineering applications in this field.

{"title":"Applying side-stream gas recirculation to promote anaerobic digestion of food waste under ammonia stress: Overlooked impact of gaseous atmospheres on microorganisms","authors":"Linyan He , Jinze Li , Lizhan Tang , Yifei Wang , Xueyu Zhao , Keke Ding , Linji Xu , Li Gu , Shang Cheng , Yi yuan Wei","doi":"10.1016/j.watres.2025.123571","DOIUrl":"10.1016/j.watres.2025.123571","url":null,"abstract":"<div><div>High ammonia concentrations can be toxic to microorganisms, leading to the accumulation of hydrogen (H<sub>2</sub>) and acids in anaerobic digestion (AD) system. In this study, a side gas recycling strategy (SGR), coupled with a primary reactor and a small side-stream reactor, which recirculates biogas between primary reactor and side reactor was employed to mitigate ammonia inhibition. This approach enabled the mesophilic side-stream gas recirculation system (SMGR) and the thermophilic side-stream gas recirculation system (STGR) to ultimately withstand ammonia stress levels of 2.5 g/L and 3.5 g/L, respectively, while maintaining lower hydrogen partial pressures. In contrast, the control group experienced system failure at an ammonia concentration of 2 g/L. Enzyme activity, microbial community, and metaproteomic analysis indicated that the side reactor enriched microorganisms with strong hydrogen-utilizing capacity, while the primary reactor was enriched with Methanosaeta. Furthermore, key pathways related to propionate metabolism, ABC transporters, and methane production were enhanced in the primary reactor, along with increased ATPase activity. The activity of key enzymes involved in AD was also significantly enhanced. This study enhances the understanding of the impact of gas atmosphere control on the microbial ecology and metabolic characteristics of AD system, providing valuable insights and practical guidance for the development of Engineering applications in this field.</div></div>","PeriodicalId":443,"journal":{"name":"Water Research","volume":"281 ","pages":"Article 123571"},"PeriodicalIF":11.4,"publicationDate":"2025-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143745217","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}

引用次数: 0

Intensifying methane emissions in Chinese Ponds: The interplay of warming, eutrophication, and depth changes

IF 11.4 1区环境科学与生态学 Q1 ENGINEERING, ENVIRONMENTAL

Water Research

Pub Date : 2025-03-31 DOI: 10.1016/j.watres.2025.123576

Mingquan Lv, Ping Huang, Xin Gao, Jilong Chen, Shengjun Wu

Ponds are significant contributors to global methane (CH₄) emissions. However, accurately estimating their historical or future CH₄ emissions remains challenging, particularly under dynamic environmental changes such as eutrophication, sedimentation-driven shallowing, and global warming. We synthesized 674 observations of CH₄ emission rates to identify key drivers and develop a process-based predictive model. We present a framework for spatially explicit estimation of pond CH₄ emissions in China from 1960 to 2020, accounting for factors such as temperature dependence, depth, nutrient levels, and pond area. Our findings show that pond CH₄ emissions are strongly temperature-dependent, characterized by a high average activation energy (0.834 eV). Notably, ebullitive emissions exhibit greater temperature sensitivity than diffusive emissions. Nitrogen concentrations and water column depth emerged as critical predictors of total CH₄ fluxes. Over the past six decades, CH₄ emissions from Chinese ponds increased approximately 9-fold, from 0.16 Tg CH₄ yr⁻¹ in 1960 to 1.53 Tg CH₄ yr⁻¹ by 2020, emphasizing their growing role in global methane emissions. Notably, half of these emissions occur during summer, with ebullition accounting for 66 % of the total CH₄ flux. This increase was primarily driven by the interactions of warming, nutrient enrichment, declining water depth, and pond expansion. Our results underscore the growing role of ponds in CH₄ emissions and highlight the urgent need for mitigation measures, such as reducing nutrient loading and implementing periodic dredging management. This study provides a robust foundation for improving CH₄ emission estimates and developing sustainable management practices for ponds in the context of global environmental change.

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引用次数: 0

Coupling effect of phytic acid and chlorite on uranium removal by Shewanella putrefaciens under simulated natural environment

IF 12.8 1区环境科学与生态学 Q1 ENGINEERING, ENVIRONMENTAL

Water Research

Pub Date : 2025-03-31 DOI: 10.1016/j.watres.2025.123582

Qingrong Li, Yang-Yang Zhang, Guo-Hao Zhang, Yilin Qin, Wencai Cheng, Xinyu Wang, Liuyuan Fu, Nan Wang, Xiaoan Li, Faqin Dong, Jun Li, Xiaoqin Nie

Understanding the transport and transformation of uranium species in surface and underground water environments, including biological migration, is a critical issue in nuclear environmental research. While it is known that uranium is primarily immobilized through reduction and mineralization with clay minerals and microorganisms, the coupled processes involving these motifs and their molecular mechanisms under multiple environmental factors remain elusive. In this work, using phytic acid (denoted as IP₆ hereinafter) as a typical organic ligand and chlorite (a layered hydrous aluminum silicate with Mg²⁺, Fe²⁺, etc.) as a typical inorganic clay mineral, we investigate the immobilization of UO₂²⁺ [abbreviated as U(VI) hereafter] by S. putrefaciens under simulated natural aerobic conditions. The experimental results show that in aerobic environment, the reduction of uranium by S. putrefaciens is inhibited, and only mineralized products are observed. In the chlorite-U(VI) system, UO₂²⁺ enters the chlorite interlayer due to internal channel restriction effects and becomes more firmly fixed over time. When there are decomposed S. putrefaciens, UO₂²⁺ is fixed by its stronger binding sites and adsorbed on the surface of chlorite. After adding phytic acid, the process of uranium biomineralization by S. putrefaciens is blocked. In the simulated aerobic four component system, some Fe²⁺ and Mg²⁺ ions dissolve from the chlorite and replace the UO₂²⁺ adsorbed by IP₆. The released UO₂²⁺ combines with the decomposing S. putrefaciens, and the complex deposits on the surface of the chlorite. At low pH values (pH<5.5), IP₆ dissolves the metal ions of the chlorite and reduces their coupling with uranium coordination. Quantum-chemical methods are utilized to interpret the experimental results at the molecular level and to provide an in-depth analysis of the interlayer structure of uranium in clay minerals. This study delves into the migration and fixation mechanisms of uranium in complex aerobic water environments, providing a theoretical basis for in-situ remediation of uranium contaminated water environments and understanding the biogeochemical behavior of nuclides in aquatic ecological environments.

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引用次数: 0

Targeting regulation of nitrate removal and chlorophenol degradation through hydrogen/oxygen switching

IF 11.4 1区环境科学与生态学 Q1 ENGINEERING, ENVIRONMENTAL

Water Research

Pub Date : 2025-03-31 DOI: 10.1016/j.watres.2025.123581

Hongfeng Lu , Juan Miao , Ning Zhang , Jiantao Ji , Ruichang Zhang , Shufa Zhu , Xuefeng Wei

Nitrate is a common co-contaminant with 2,4-dichlorophenol (2,4-DCP) in water, presenting a challenge for environmental remediation. Under anaerobic conditions, the ring cleavage of chlorophenol is inefficient, while under aerobic conditions, nitrate removal is hindered. In this study, a microbial consortium capable of hydrogenotrophic denitrification and 2,4-DCP degradation was cultured, aiming to achieve efficient nitrate removal and 2,4-DCP degradation by alternately switching between hydrogen (H₂) and oxygen (O₂). Under H₂ conditions, nitrate removal exceeded 90 %, while under O₂ conditions, 2,4-DCP degradation reached 100 %. Under H₂ conditions, the abundance of the Nar gene which was involved in nitrate reduction was higher than that under O₂ conditions, promoting hydrogenotrophic denitrification. In contrast, under O₂ conditions, 2,4-DCP degradation occurred via hydroxylation, ring-cleavage, dechlorination, and mineralization through the TCA cycle. Metagenomic and metabolomic analysis was performed to explore microbial metabolic pathways and potential synergistic mechanisms involved in hydrogenotrophic denitrification and 2,4-DCP biodegradation. In the H₂-atmosphere, microbes (Methylobacillus and Chromobacterium), genes (E3.1.1.45 and speG), and metabolites (Cytosine and Uridine) may play a crucial role in hydrogenotrophic denitrification. In the O₂-atmosphere, the functional genus of Paracoccus and Aquamicrobium associated with genes (tfdB and tfdC) may contribute to 2,4-DCP and its metabolites 2-Chloromaleylacetate degradation. These findings confirmed the role of functional microbial communities through H₂/O₂ regulation. This work provides a promising technological reference for treating industrial wastewater containing phenols and nitrogen.

{"title":"Targeting regulation of nitrate removal and chlorophenol degradation through hydrogen/oxygen switching","authors":"Hongfeng Lu , Juan Miao , Ning Zhang , Jiantao Ji , Ruichang Zhang , Shufa Zhu , Xuefeng Wei","doi":"10.1016/j.watres.2025.123581","DOIUrl":"10.1016/j.watres.2025.123581","url":null,"abstract":"<div><div>Nitrate is a common co-contaminant with 2,4-dichlorophenol (2,4-DCP) in water, presenting a challenge for environmental remediation. Under anaerobic conditions, the ring cleavage of chlorophenol is inefficient, while under aerobic conditions, nitrate removal is hindered. In this study, a microbial consortium capable of hydrogenotrophic denitrification and 2,4-DCP degradation was cultured, aiming to achieve efficient nitrate removal and 2,4-DCP degradation by alternately switching between hydrogen (H<sub>2</sub>) and oxygen (O<sub>2</sub>). Under H<sub>2</sub> conditions, nitrate removal exceeded 90 %, while under O<sub>2</sub> conditions, 2,4-DCP degradation reached 100 %. Under H<sub>2</sub> conditions, the abundance of the <em>Nar</em> gene which was involved in nitrate reduction was higher than that under O<sub>2</sub> conditions, promoting hydrogenotrophic denitrification. In contrast, under O<sub>2</sub> conditions, 2,4-DCP degradation occurred via hydroxylation, ring-cleavage, dechlorination, and mineralization through the TCA cycle. Metagenomic and metabolomic analysis was performed to explore microbial metabolic pathways and potential synergistic mechanisms involved in hydrogenotrophic denitrification and 2,4-DCP biodegradation. In the H<sub>2</sub>-atmosphere, microbes (<em>Methylobacillus</em> and <em>Chromobacterium</em>), genes (<em>E3.1.1.45</em> and <em>speG</em>), and metabolites (Cytosine and Uridine) may play a crucial role in hydrogenotrophic denitrification. In the O<sub>2</sub>-atmosphere, the functional genus of <em>Paracoccus</em> and <em>Aquamicrobium</em> associated with genes (<em>tfdB</em> and <em>tfdC</em>) may contribute to 2,4-DCP and its metabolites 2-Chloromaleylacetate degradation. These findings confirmed the role of functional microbial communities through H<sub>2</sub>/O<sub>2</sub> regulation. This work provides a promising technological reference for treating industrial wastewater containing phenols and nitrogen.</div></div>","PeriodicalId":443,"journal":{"name":"Water Research","volume":"281 ","pages":"Article 123581"},"PeriodicalIF":11.4,"publicationDate":"2025-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143745150","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}

引用次数: 0

Fenton–coagulation process for simultaneous abatement of micropollutants and dissolved organic carbon in treated wastewater

IF 11.4 1区环境科学与生态学 Q1 ENGINEERING, ENVIRONMENTAL

Water Research

Pub Date : 2025-03-31 DOI: 10.1016/j.watres.2025.123583

Cheolyong Kim , Philipp Debusmann , Mohammad Sajjad Abdighahroudi , Jochen Schumacher , Holger V. Lutze

This study demonstrates the integration of the Fenton reaction into the flocculation process at circumneutral pH (6–7), offering a practical approach for simultaneous micropollutant and organic matter removal in wastewater treatment. Unlike conventional Fenton oxidation, which requires acidic conditions, this approach allows Fe(II) to react with hydrogen peroxide at near-neutral pH, forming Fe(III) flocs that enhance flocculation while also generating reactive species for pollutant degradation. At pH 6, hydroxyl radicals were the dominant oxidants, whereas at pH 7, additional reactive species likely contributed to micropollutant removal. Bisphenol A and benzoic acid were removed by approximately 90% at 1 mM peroxide and 2 mM iron. In addition to micropollutant degradation, the Fenton-coagulation process achieved substantial dissolved organic carbon (DOC) removal, which was not observed with Fenton oxidation alone or ozonation. DOC removal was up to 51% in Suwannee River Natural Organic Matter solutions, whereas only 30% of DOC was removed from municipal wastewater effluent, likely due to differences in organic matter composition. These findings highlight the potential of Fenton-coagulation as an effective and scalable treatment strategy for wastewater reuse, improving both pollutant degradation and organic matter removal under practical conditions.

{"title":"Fenton–coagulation process for simultaneous abatement of micropollutants and dissolved organic carbon in treated wastewater","authors":"Cheolyong Kim , Philipp Debusmann , Mohammad Sajjad Abdighahroudi , Jochen Schumacher , Holger V. Lutze","doi":"10.1016/j.watres.2025.123583","DOIUrl":"10.1016/j.watres.2025.123583","url":null,"abstract":"<div><div>This study demonstrates the integration of the Fenton reaction into the flocculation process at circumneutral pH (6–7), offering a practical approach for simultaneous micropollutant and organic matter removal in wastewater treatment. Unlike conventional Fenton oxidation, which requires acidic conditions, this approach allows Fe(II) to react with hydrogen peroxide at near-neutral pH, forming Fe(III) flocs that enhance flocculation while also generating reactive species for pollutant degradation. At pH 6, hydroxyl radicals were the dominant oxidants, whereas at pH 7, additional reactive species likely contributed to micropollutant removal. Bisphenol A and benzoic acid were removed by approximately 90% at 1 mM peroxide and 2 mM iron. In addition to micropollutant degradation, the Fenton-coagulation process achieved substantial dissolved organic carbon (DOC) removal, which was not observed with Fenton oxidation alone or ozonation. DOC removal was up to 51% in Suwannee River Natural Organic Matter solutions, whereas only 30% of DOC was removed from municipal wastewater effluent, likely due to differences in organic matter composition. These findings highlight the potential of Fenton-coagulation as an effective and scalable treatment strategy for wastewater reuse, improving both pollutant degradation and organic matter removal under practical conditions.</div></div>","PeriodicalId":443,"journal":{"name":"Water Research","volume":"281 ","pages":"Article 123583"},"PeriodicalIF":11.4,"publicationDate":"2025-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143745233","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}

引用次数: 0

Utilization of enhanced electrolytic bubbles in electrooxidation for efficient refractory organics removal

IF 11.4 1区环境科学与生态学 Q1 ENGINEERING, ENVIRONMENTAL

Water Research

Pub Date : 2025-03-30 DOI: 10.1016/j.watres.2025.123579

Zhongsen Yan , Xiaolei Chen , Huarong Yu , Fangshu Qu , Dan Qu , Haiqing Chang , Bart Van der Bruggen

Although electrooxidation can remove refractory organics, a significant amount of energy is required for non-selective oxidation, and the oxygen evolution reaction (OER) contributes little to the process. In this study, the conventional electrolytic bubbles were enhanced to improve the performance of organic matter removal. Using humic acid as a model recalcitrant organic pollutant, a membrane electrochemical reactor (MER) was designed to separate mixed bubbles (e.g., H₂ and O₂) produced during electrooxidation with a diaphragm, thereby dividing the individual MER O₂ and MER H₂. The bubbles stability of MER O₂ was higher than that of conventional electrooxidation and aeration, which facilitated the removal of humic acid. Surfactants with different electrical characteristics were further used to enhance the interaction between the bubbles and humic acid. After the addition of cetyltrimethylammonium bromide (CTAB 80 mg/L), the positive charge of the MER O₂ bubbles intensified, inducing the removal of 92.8 % humic acid (250 mg/L) with an oxidation rate <3.7 %. Moreover, CTAB could be reused after foam fractionation. Using zeta potential distribution theory, the initial electrical properties of MER O₂ (+) and MER H₂ (-) were clarified, as well as the charge intensification by CTAB on MER O₂ bubbles. Besides, the acidification by MER imparted initial electrical properties to the bubbles and led to the aggregation of humic acid, and the humic acid adhering to the bubbles further isolated the merging of the bubbles. The application of enhanced electrolytic bubbles offers a novel approach to reducing energy consumption in humic acid removal via electrooxidation systems.

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引用次数: 0

Treatment options of nitrogen heterocyclic compounds in industrial wastewater: From fundamental technologies to energy valorization applications and future process design strategies

IF 11.4 1区环境科学与生态学 Q1 ENGINEERING, ENVIRONMENTAL

Water Research

Pub Date : 2025-03-29 DOI: 10.1016/j.watres.2025.123575

Chao Ma , Huiqin Zhang , Ziwei Liu , Xinran Meng , Sijia Chen , Jingsong Zhang , Yeqiang Li , Xia Huang

Nitrogen heterocyclic compounds (NHCs) widely exist in industrial wastewater and presented significant environmental and health risks due to their toxicity and persistence. This review addressed the challenges in treating NHCs in industrial wastewater, focusing on developing sustainable and efficient treatment processes. While various technologies, including adsorption, advanced oxidation/reduction processes (AOPs/ARPs), and microbial treatments, have been studied at the experimental stage of treating synthetic wastewater, scale-up for industrial applications is imperative. After analyzing the characteristics of NHCs and evaluating different treatment methods with the aid of efficiency and cost-benefit analysis, efficient detoxification while maximizing energy recovery constitutes a critical requirement in treating NHC-containing wastewater. Hence, we proposed a comprehensive strategy combining hydrolysis-acidification pretreatment enhanced by electro-assisted micro-aeration with methanogenic anaerobic digestion as core treatment units. The process design for NHC-containing wastewater treatment should consider the dynamic balance between removal efficiency, energy consumption, and ammonia recovery, incorporating environmental and economic impacts through life cycle assessment and technical-economic analysis. The potential of machine learning in optimizing operational parameters, predicting effluent quality, and supporting process design decisions is promising. To develop interpretable and practical solutions, the integration of data-driven approaches with mechanistic understanding and prior knowledge is indispensable. This review provided novel insights into sustainable NHC treatment strategies in the context of energy valorization and artificial intelligence advancement, offering guidance for future research and industrial applications.

氮杂环化合物（NHCs）广泛存在于工业废水中，由于其毒性和持久性，给环境和健康带来了巨大风险。本综述探讨了处理工业废水中的氮杂环化合物所面临的挑战，重点是开发可持续的高效处理工艺。虽然在处理合成废水的实验阶段已经研究了各种技术，包括吸附、高级氧化/还原过程（AOPs/ARPs）和微生物处理，但扩大工业应用规模势在必行。在分析了 NHC 的特性并借助效率和成本效益分析评估了不同的处理方法后，高效解毒同时最大限度地回收能量成为处理含 NHC 废水的关键要求。因此，我们提出了一种将水解酸化预处理与电助微曝气强化相结合的综合策略，并将甲烷厌氧消化作为核心处理单元。含 NHC 废水处理的工艺设计应考虑去除效率、能耗和氨回收之间的动态平衡，并通过生命周期评估和技术经济分析将环境和经济影响纳入其中。机器学习在优化运行参数、预测出水水质和支持工艺设计决策方面具有巨大潜力。要开发可解释且实用的解决方案，就必须将数据驱动方法与机理理解和先验知识相结合。本综述在能源价值化和人工智能进步的背景下，对可持续的 NHC 处理策略提出了新的见解，为未来的研究和工业应用提供了指导。

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引用次数: 0

Cyanobacterial blooms specifically alter the dispersal-mediated taxonomic and functional vertical similarity of microbial communities in a subtropical reservoir

IF 11.4 1区环境科学与生态学 Q1 ENGINEERING, ENVIRONMENTAL

Water Research

Pub Date : 2025-03-29 DOI: 10.1016/j.watres.2025.123574

Shuzhen Li , Xue Yan , Huihuang Chen , Erik Jeppesen , Peng Xiao , Lei Jin , Zijie Xu , Jun Zuo , Kexin Ren , Jun Yang

Harmful cyanobacterial blooms, including Raphidiopsis raciborskii (basionym Cylindrospermopsis raciborskii), are an increasing environmental concern in freshwater ecosystems globally. However, the ecological consequences of cyanobacterial blooms for the vertical similarity of microbial community structure have yet to be thoroughly investigated, especially in deep waters. Here, we explored the taxonomic and functional similarity of microbial communities at different depths in a subtropical reservoir over a 7-year period following multiple R. raciborskii blooms. Our results showed that vertical microbial dispersal, rather than ecological niche, is the main process determining vertical similarity. Both particle-attached (PA) and free-living (FL) bacteria from the surface water were able to reach the deep water, particle size being a contributing factor to their vertical dispersal. Cyanobacterial blooms enhanced the vertical microbial transport of PA, impacting the composition and biogeochemical processes of deep microbial communities. During the mixing period, microbial taxonomic and functional similarities between the different water layers were high whereas they were minimal across the oxycline during the stratification period, suggesting a bottleneck in microbial vertical dispersal. In the deep water layers, the abundances of specific taxa, such as those of Burkholderiales and Desulfomonilales in PA and FL fractions respectively in stratification periods, increased during blooms. Additionally, cyanobacterial blooms enhanced sulfur compound respiration in both PA and FL fractions and suppressed nitrification in PA bacteria and denitrification in FL bacteria, simultaneously reducing light-utilization capacity in PA bacteria and altering organic matter degradation. Several mechanisms are proposed to drive variations in microbial vertical connectivity by cyanobacteria, including ecological niche shifts and alterations of physicochemical properties and nutrient dynamics. Overall, our results reveal complex effects of cyanobacterial blooms on microbial taxonomic and functional vertical similarity and highlight the contribution of surface communities to the biodiversity and biogeography of deep communities.

包括 Raphidiopsis raciborskii（原名 Cylindrospermopsis raciborskii）在内的有害蓝藻水华日益成为全球淡水生态系统中的环境问题。然而，蓝藻藻华对微生物群落结构垂直相似性的生态影响尚未得到深入研究，尤其是在深水区。在此，我们探索了一个亚热带水库在多次 R. raciborskii 藻华发生后的 7 年间不同深度微生物群落的分类和功能相似性。我们的研究结果表明，决定垂直相似性的主要过程是微生物的垂直扩散，而不是生态位。来自表层水的颗粒附着细菌（PA）和自由生活细菌（FL）都能到达深层水，颗粒大小是它们垂直扩散的一个促成因素。蓝藻水华增强了 PA 的垂直微生物迁移，影响了深层微生物群落的组成和生物地球化学过程。在混合期间，不同水层之间的微生物分类学和功能相似性很高，而在分层期间，不同水层之间的微生物分类学和功能相似性很小，这表明微生物的垂直扩散存在瓶颈。在深水层，特定门类和纲的丰度在藻华期间有所增加，如在分层期 PA 和 FL 部分的 Burkholderiales 和 Desulfomonilales。此外，蓝藻藻华增强了 PA 和 FL 部分的硫化合物呼吸作用，抑制了 PA 细菌的硝化作用和 FL 细菌的反硝化作用，同时降低了 PA 细菌的光利用能力并改变了有机物降解。蓝藻微生物垂直连通性的变化有多种驱动机制，包括生态位转移、理化性质和营养动态的改变。总之，我们的研究结果揭示了蓝藻藻华对微生物分类和功能垂直相似性的复杂影响，并强调了表层群落对深层群落生物多样性和生物地理学的贡献。

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引用次数: 0

Biodegradation pathways and mechanisms of 17α-ethynylestradiol via functional enzymes in the freshwater microalga Scenedesmus quadricauda

IF 11.4 1区环境科学与生态学 Q1 ENGINEERING, ENVIRONMENTAL

Water Research

Pub Date : 2025-03-29 DOI: 10.1016/j.watres.2025.123569

Xiaomin Wu , Yuwen Wang , James P. Meador , Guang-Jie Zhou , Wenju Xu , Feng Hua , Wenhua Liu , Xiaojuan Liu , Zhen Wang

17α-ethynylestradiol (EE2) is a potent synthetic hormone exhibiting very high estrogenic activity and low rates of biodegradation. The removal capabilities of EE2 by bacteria, fungi and algal-bacterial symbiotic systems have attracted considerable attention recently. Specifically, algal biodegradation has been explored recently; however, the pathway and mechanisms of EE2 degradation have remained largely unknown. Therefore, we investigated the pathways and mechanisms by which EE2 is degraded by the freshwater microalga Scenedesmus quadricauda. After exposure for 10.5 d, the algal species was able to metabolize 58 % of a 15 mg/L solution of EE2, with the highest removal rate of 13 % occurring at 1.5 d An Ultra Performance Liquid Chromatography-Q-Exactive Orbitrap Mass Spectrometry was used innovatively to identify the biodegradation products of EE2 through non-target screening, followed by the verification of standard compounds. Transcriptomic analysis and molecular docking analysis revealed several degradation pathways and mechanisms by this algal species. One pathway was the demethylation of EE2 to estradiol (E2) by short-chain dehydrogenase/reductase. Subsequently, we also observed interconversion of estrone (E1) and E2 by 17β-hydroxysteroid dehydrogenase through hydroxylation or ketonization, hydroxylation of E1 to 16α-hydroxyestrone (16-OH E1) by cytochrome P450 and flavin-containing monooxygenase. A second pathway was methoxylation of E2 to estradiol acetate by catechol O-methyltransferase. As a result, the ethynyl group was degraded to hydroxy, ketone and methoxyl groups, which promotes EE2 degradation. Considering that EE2 pollution could result in adverse effects for aquatic organisms, the results of this study provide insights and a comprehensive approach for practical and effective bioremediation of EE2 contamination in aquatic ecosystems.

17α-乙炔基雌二醇（EE2）是一种强效合成激素，具有很高的雌激素活性，但生物降解率很低。最近，细菌、真菌和藻类-细菌共生系统清除 EE2 的能力引起了广泛关注。特别是最近对藻类生物降解进行了探索，但 EE2 降解的途径和机制在很大程度上仍然未知。因此，我们研究了淡水微藻 Scenedesmus quadricauda 降解 EE2 的途径和机制。该研究创新性地使用了超高效液相色谱-Q-Exactive Orbitrap质谱仪，通过非目标筛选确定了EE2的生物降解产物，然后对标准化合物进行了验证。转录组分析和分子对接分析揭示了这种藻类的几种降解途径和机制。其中一条途径是通过短链脱氢酶/还原酶将 EE2 去甲基化为雌二醇（E2）。随后，我们还观察到 17β- 羟基类固醇脱氢酶通过羟基化或酮化作用将雌酮（E1）和 E2 相互转化，细胞色素 P450 和含黄素单氧化酶将 E1 羟基化为 16α- 羟基雌酮（16-OH E1）。第二个途径是儿茶酚 O-甲基转移酶将 E2 甲氧基化为乙酸雌二醇。因此，乙炔基降解为羟基、酮基和甲氧基，从而促进了 EE2 的降解。考虑到 EE2 污染会对水生生物造成不利影响，本研究的结果为切实有效地对水生生态系统中的 EE2 污染进行生物修复提供了见解和综合方法。

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引用次数: 0