Water Research最新文献

{"title":"Unveiling the reaction chemistry of sulfoxides during water chlorination.","authors":"Jiwoon Ra, Julie Tolu, Daniel Rentsch, Tarek Manasfi, Urs von Gunten","doi":"10.1016/j.watres.2024.122806","DOIUrl":"https://doi.org/10.1016/j.watres.2024.122806","url":null,"abstract":"<p><p>Species-specific second-order rate constants for the reactions of eight model sulfoxides with hypochlorous acid (k_HOCl) were determined to be in the range of 2.7 M^-1 s^-1 to 5.8 × 10³M^-1 s^-1. A quantitative structure-activity relationships (QSAR) with Taft σ* constants was developed based on eight measured k_HOCl-values, showing a good linear correlation (R² = 0.89) with a negative slope ρ = -1.5 typical for electrophilic reactions. The reaction is mainly controlled by HOCl, with a minor contribution of OCl^-. The contributions of other reactive chlorine species (e.g., Cl₂ and Cl₂O) to the overall kinetics are only 7 % for Cl₂O and 5 % for Cl₂ under typical drinking water treatment conditions. A combination of several analytical methods (HPLC-MS/MS, HPLC-ICP-MS/MS, and NMR) was applied for the identification of transformation products. Major transformation products from the reactions of chlorine with sulfoxides are sulfones, Cl-substituted sulfoxides, aldehydes, and sulfonic acids potentially formed via a transient chlorosulfonium cation. In general, sulfoxides react more readily with chlorine compared to bromine. This might be caused by a partial positive charge on the sulfur which leads to a stronger interaction with Cl in HOCl having a smaller partial positive charge than Br in HOBr. The ratios of the species-specific second-order rate constants for the reactions of the selected sulfoxides with chlorine or bromine (k_HOCl/k_HOBr) range from 6 to 480. For sulfoxide compounds with strong electron-withdrawing substituents the reaction occurs most likely via a carbanion intermediate for which the reaction with HOBr is preferred, resulting in a k_HOCl/k_HOBr = 0.8.</p>","PeriodicalId":443,"journal":{"name":"Water Research","volume":"270 ","pages":"122806"},"PeriodicalIF":11.4,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142805703","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":"Microbial biomass stoichiometry and proportion of Fe organic complexes separately shape the heterogeneity of mixotrophic denitrification and net N2O sinks in iron-carbon amended ecological ditch","authors":"Bi-Ni Jiang, Ying-Ying Zhang, Yan Wang, Hai-qin Liu, Zhi-Yong Zhang, Yi-Jing Yang, Hai-Liang Song","doi":"10.1016/j.watres.2024.122945","DOIUrl":"https://doi.org/10.1016/j.watres.2024.122945","url":null,"abstract":"Coupling of iron-carbon can form a mixotrophic denitrification and is regarded as a promising solution for purifying nitrate-rich agricultural runoff. However, its prevalence and efficacy of the synergistic augmentation of nitrogen elimination and net N₂O sinks remain crucial knowledge gaps in ecological ditches (eco-ditches). Here, we investigated the underlying variability mechanisms by implementing sponge iron (sFe)-coupled <em>Iris hexagonus</em> (<em>IH</em>)<em>-</em> or <em>Myriophyllum aquaticum</em> (<em>MA</em>)<em>-</em>derived biochar produced via microwave-assisted (MW) pyrolysis and conventional pyrolysis. Surprisingly, unamened eco-ditch became net N₂O sink while exhibiting a significant increase in total nitrogen (TN) removal rate of 319% (<em>P</em> &lt; 0.001) compared to soil ditch. The integration of MW pyrolyzed <em>IH-</em>derived biochar with sFe to amend eco-ditch achieved synchronous enhancement in net N₂O sinks (<em>P</em> &lt; 0.01) and TN removal rate (<em>P</em> &lt; 0.001), whereas the remaining amended eco-ditches that significantly intensified TN removal performance, were N₂O emitters. Such heterogeneity primarily depends on Fe organic complexes (Fep) / the total reactive Fe oxides (Fed) ratio, rather than the prevailing <em>nosZ</em> gene, underscoring that low density metastable reactive iron plays a more important role than biological reactions during the mixotrophic denitrification process. As such, iron oxides are not necessarily a bottleneck for denitrification and contribute to N₂O sinks. Conversely, microbial biomass C:(C+N), together with <em>nirK</em> and <em>nosZ</em> genes, mainly explain the TN removal heterogeneity of sFe–biochar eco-ditch. This study revisits the discrepant resilience of iron-carbon coupling to N abatement and N₂O sink-induced cooling and has significant practical implications for better understanding the cascading effects of mixotrophic denitrification driven by iron-carbon interactions.","PeriodicalId":443,"journal":{"name":"Water Research","volume":"12 1","pages":""},"PeriodicalIF":12.8,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142797636","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":"Illuminating for purity: photocatalytic and photothermal membranes for sustainable oil-water separation","authors":"Hongyuan Zhu, Zhenyu Guo, Wei Yu, Shasha Yuan, Liguo Shen, Die Ling Zhao, Hongjun Lin","doi":"10.1016/j.watres.2024.122919","DOIUrl":"https://doi.org/10.1016/j.watres.2024.122919","url":null,"abstract":"The integration of photocatalytic and photothermal materials with oil-water separation membranes marks a significant advancement in sustainable separation technologies. These hybrid membranes exhibit exceptional functionalities, including resistance to oil fouling, self-cleaning, antibacterial properties, and reduced oil viscosity. Based on their reaction mechanisms, current photocatalytic and photothermal membranes are categorized into four types, i.e., photocatalytic membranes, photo-Fenton membranes, PMS-assisted photocatalytic membranes, and photothermal membranes. Under light irradiation, photocatalytically functionalized membranes generate reactive oxygen species (ROS) that degrade organic pollutants and inactivate bacteria on the membrane surfaces, enabling in-situ cleaning and regeneration. In addition to the above benefits, photothermal membranes achieve reduction of oil viscosity for higher membrane permeation and removal of light oil from membrane surfaces through light-induced heating. This review first explores the mechanisms underlying light-driven advanced oxidation processes (AOPs) and photothermal effects, followed by an in-depth discussion on the fabrication methods of these membranes. Additionally, the applications of photocatalytic and photothermal membranes in oil-water separation are examined, with an emphasis on how the photocatalytic and photothermal materials contribute to membrane functionality. Finally, this review presents the challenges currently faced by photocatalytic and photothermal membranes and outlines future research directions.","PeriodicalId":443,"journal":{"name":"Water Research","volume":"113 1","pages":""},"PeriodicalIF":12.8,"publicationDate":"2024-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142789849","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":"Toxin production in bloom-forming, harmful alga Alexandrium pacificum (Group IV) is regulated by cyst formation-promoting bacteria Jannaschia cystaugens NBRC 100362T","authors":"Yue Jiang, Rishiram Ramanan, Sungae Yoon, Bo-Mi Lee, Yoon-Ho Kang, Zhun Li","doi":"10.1016/j.watres.2024.122930","DOIUrl":"https://doi.org/10.1016/j.watres.2024.122930","url":null,"abstract":"Harmful algal blooms (HABs) caused by dinoflagellates like <em>Alexandrium pacificum</em> pose significant ecological and public health risks due to their production of paralytic shellfish toxins (PSTs). Bacterial populations, particularly <em>Alexandrium</em> cyst formation-promoting bacteria (Alex-CFPB), are known to significantly influence growth, encystment, toxin synthesis, the composition of toxic components, and bloom dynamics of these dinoflagellates. However, the role of Alex-CFPB in <em>Alexandrium</em> toxin synthesis and the mechanisms thereof are still unclear. Here, we show that co-culturing <em>A. pacificum</em> with cyst formation-promoting bacteria <em>Jannaschia cystaugens</em> significantly increases total intracellular PSTs content in the late stationary phase (including more cysts and less vegetable cells compared with axenic group). Our results demonstrate that the presence of <em>J. cystaugens</em> alters metabolic pathways in <em>A. pacificum</em> by upregulating key paralytic shellfish toxins synthesis genes and inducing downregulation of sulfotransferase <em>sxtN</em> (related to PSTs sulfation) which decreases sulfated PSTs components (low-toxicity), leading to an increase in high-toxicity PSTs content at a single-cell level. Furthermore, bacterial oxidative stress signals, nutrient competition, and quorum sensing contribute to increased toxin synthesis. These results provide insights into the major role of bacteria in modulating growth, physiology, and toxin production in bloom-forming algae, and the complex regulatory mechanisms therein. This study thus defines the critical function of microbial associations in bloom formation and toxin production with implications for managing HABs and mitigating their impacts.","PeriodicalId":443,"journal":{"name":"Water Research","volume":"27 1","pages":""},"PeriodicalIF":12.8,"publicationDate":"2024-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142789840","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":"Bed-immersion-ratio variation as an efficient strategy to regulate denitrification efficiency directionally in elemental sulfur packed-bed reactors","authors":"Guijiao Zhang, Hao-Ran Xu, Wenwei Liao, Jia-Min Xu, Na Zhang, Daheng Ren, Xinjie Chen, Wenyan Mao, Xiangli Zeng, Aijie Wang, Hao-Yi Cheng","doi":"10.1016/j.watres.2024.122941","DOIUrl":"https://doi.org/10.1016/j.watres.2024.122941","url":null,"abstract":"Autotrophic denitrification in sulfur packed-bed reactors (S&lt;sup&gt;0&lt;/sup&gt;PBR) has been widely employed for treating ໿municipal secondary effluent. However, the fixed volume of packed sulfur in S&lt;sup&gt;0&lt;/sup&gt;PBR restricts the ability to adjust denitrification efficiency in response to fluctuating influent nitrate levels, leading to either effluent standard exceedances or unnecessary sulfur consumption. Here, we proposed a novel method for directionally regulating nitrate removal efficiency (NRE) in S&lt;sup&gt;0&lt;/sup&gt;PBR by adjusting the bed-immersion-ratio (BIR). The results demonstrated that the NRE could be effectively controlled through adjustments of BIR, with the maximum NRE achieved when BIR was increased to 1.00. Notably, a non-zero minimum NRE was observed when BIR decreased to 0.00. This could be associated with actual hydraulic retention time (aHRT), with a strong correlation observed between aHRT and BIR. Based on these findings, a kinetic model was developed that integrated both exposure and immersion parts, expressed as &lt;span&gt;&lt;span style=\"\"&gt;&lt;/span&gt;&lt;span data-mathml='&lt;math xmlns=\"http://www.w3.org/1998/Math/MathML\"&gt;&lt;mrow is=\"true\"&gt;&lt;msub is=\"true\"&gt;&lt;mi is=\"true\"&gt;R&lt;/mi&gt;&lt;mi is=\"true\"&gt;j&lt;/mi&gt;&lt;/msub&gt;&lt;mo linebreak=\"goodbreak\" is=\"true\"&gt;=&lt;/mo&gt;&lt;mfrac is=\"true\"&gt;&lt;mrow is=\"true\"&gt;&lt;mo is=\"true\"&gt;(&lt;/mo&gt;&lt;mrow is=\"true\"&gt;&lt;msubsup is=\"true\"&gt;&lt;mi is=\"true\"&gt;C&lt;/mi&gt;&lt;mrow is=\"true\"&gt;&lt;mi is=\"true\"&gt;i&lt;/mi&gt;&lt;mi is=\"true\"&gt;n&lt;/mi&gt;&lt;mo is=\"true\"&gt;&amp;#x2212;&lt;/mo&gt;&lt;mn is=\"true\"&gt;0&lt;/mn&gt;&lt;/mrow&gt;&lt;mrow is=\"true\"&gt;&lt;mn is=\"true\"&gt;1&lt;/mn&gt;&lt;mo is=\"true\"&gt;/&lt;/mo&gt;&lt;mn is=\"true\"&gt;2&lt;/mn&gt;&lt;/mrow&gt;&lt;/msubsup&gt;&lt;mo is=\"true\"&gt;&amp;#x2212;&lt;/mo&gt;&lt;msubsup is=\"true\"&gt;&lt;mi is=\"true\"&gt;C&lt;/mi&gt;&lt;mi is=\"true\"&gt;e&lt;/mi&gt;&lt;mrow is=\"true\"&gt;&lt;mn is=\"true\"&gt;1&lt;/mn&gt;&lt;mo is=\"true\"&gt;/&lt;/mo&gt;&lt;mn is=\"true\"&gt;2&lt;/mn&gt;&lt;/mrow&gt;&lt;/msubsup&gt;&lt;/mrow&gt;&lt;mo is=\"true\"&gt;)&lt;/mo&gt;&lt;mi is=\"true\"&gt;Q&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow is=\"true\"&gt;&lt;mn is=\"true\"&gt;2.54&lt;/mn&gt;&lt;mi is=\"true\"&gt;A&lt;/mi&gt;&lt;msub is=\"true\"&gt;&lt;mi is=\"true\"&gt;H&lt;/mi&gt;&lt;mi is=\"true\"&gt;t&lt;/mi&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/mfrac&gt;&lt;mo linebreak=\"goodbreak\" is=\"true\"&gt;&amp;#x2212;&lt;/mo&gt;&lt;mn is=\"true\"&gt;0.65&lt;/mn&gt;&lt;/mrow&gt;&lt;/math&gt;' role=\"presentation\" style=\"font-size: 90%; display: inline-block; position: relative;\" tabindex=\"0\"&gt;&lt;svg aria-hidden=\"true\" focusable=\"false\" height=\"5.432ex\" role=\"img\" style=\"vertical-align: -1.389ex;\" viewbox=\"0 -1740.8 10861.3 2338.9\" width=\"25.226ex\" xmlns:xlink=\"http://www.w3.org/1999/xlink\"&gt;&lt;g fill=\"currentColor\" stroke=\"currentColor\" stroke-width=\"0\" transform=\"matrix(1 0 0 -1 0 0)\"&gt;&lt;g is=\"true\"&gt;&lt;g is=\"true\"&gt;&lt;g is=\"true\"&gt;&lt;use xlink:href=\"#MJMATHI-52\"&gt;&lt;/use&gt;&lt;/g&gt;&lt;g is=\"true\" transfo","PeriodicalId":443,"journal":{"name":"Water Research","volume":"1 1","pages":""},"PeriodicalIF":12.8,"publicationDate":"2024-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142793399","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":"Making Waves: Unraveling microplastic deposition in rivers through the lens of sedimentary processes","authors":"Shai Arnon","doi":"10.1016/j.watres.2024.122934","DOIUrl":"https://doi.org/10.1016/j.watres.2024.122934","url":null,"abstract":"River networks are the major pathways for microplastic (MP) transport from terrestrial environments to oceans. It is essential to understand where MPs reside and how they move along river networks because of their potential to negatively impact ecosystems. However, the ability to quantify the water–sediment exchange of MPs, locations of deposition, and the time scales over which burial occurs is limited. To fill this gap, previous work on processes that control MP deposition are briefly reviewed in this Perspective paper, with the aim of enhancing our understanding of the dynamic interplay between flow, sediment transport, and MP movement through river networks. Detailed studies on MP deposition onto surficial sediment show that MP transport can be explained by the shear stress theory, hyporheic exchange, and bioturbation. Nevertheless, these processes cannot fully explain the observed distribution of MPs in deeper river sediments. It is proposed that bedform movement, channel reworking, bar formation, and aggradation/degradation at the river network scale should be included when estimating MP deposition. It is argued that incorporating data on MP distribution in riverbeds with fluvial geomorphological and particle transport models will improve the current evaluation of MP transport in river networks and their burial residence time distribution.","PeriodicalId":443,"journal":{"name":"Water Research","volume":"9 1","pages":""},"PeriodicalIF":12.8,"publicationDate":"2024-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142793258","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":"Reverse-engineered Electro-Fenton for the selective synthesis of oxalic or oxamic acid through the degradation of acetaminophen: a novel green electrocatalytic refinery approach","authors":"Hugo Olvera-Vargas, Quetzalli Fernández González, Rosa Angélica Guillén Garcés, Marina E. Rincón","doi":"10.1016/j.watres.2024.122914","DOIUrl":"https://doi.org/10.1016/j.watres.2024.122914","url":null,"abstract":"The Electro-Fenton process (EF) has been conventionally applied to efficiently degrade refractory and/or toxic pollutants. However, in this work, EF was used as a reverse engineering tool to selectively synthesize highly value-added products (oxalic or oxamic acid) through the degradation of the model pollutant acetaminophen, a widely used analgesic and antipyretic drug. It was found that the production of either oxalic or oxamic acid is dictated by the applied current density. Hence, oxalic acid is favored at low current densities trough a mechanism dominated by homogeneous ^•OH radical oxidation, while oxamic acid is the majoritarian product at high current densities where electron transfer at the anode surface becomes an important mechanism in combination with ^•OH oxidation. Under optimal reaction conditions (0.71 mA cm^-2 and 100 mg L^-1 of initial total organic carbon (TOC) concentration), up to 227.1 ± 26.3 mg L^-1 of oxalic acid were produced, with high yield and selectivity of 54.9 ± 5.1% and 94.7 ± 9.9%, respectively (the TOC removal was 42.0 ± 2.4%). In the case of oxamic acid, the highest concentration of 33.8 ± 2.1 mg L^-1 was produced at 2.13 mA cm^-2 and an initial TOC concentration of 50 mg L^-1, which represented a yield of 18.7 ± 0.3% and 60.9 ± 9.3% selectivity (71.1 ± 4.4% of TOC removal). It is worth noting that at low current density when oxalic acid is favored, the selectivity for both products was 100%, meaning that those were the only products remaining in the solution, with oxalic acid as the major product (94.7 ± 9.9% with initial TOC of 100 mg L^-1, and 98.7 ± 0.9% with initial TOC of 50 mg L^-1). This is a pioneer work on EF applications to the field of wastewater valorization/refining through the recovery of value-added products within a circular economy.","PeriodicalId":443,"journal":{"name":"Water Research","volume":"20 1","pages":""},"PeriodicalIF":12.8,"publicationDate":"2024-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142788526","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":"Making Waves: The Potential of Generative AI in Water Utility Operations","authors":"Lina Sela, Robert B. Sowby, Elad Salomons, Mashor Housh","doi":"10.1016/j.watres.2024.122935","DOIUrl":"https://doi.org/10.1016/j.watres.2024.122935","url":null,"abstract":"Water utilities facing increasingly complex infrastructure and operations stand to significantly benefit from artificial intelligence (AI). Current research in water distribution systems engineering primarily focuses on <em>Specialized AI</em>, which plays a crucial role in processing extensive datasets, identifying patterns, and extracting actionable insights to improve the resilience and efficiency of water utility operations. However, barriers such as high implementation costs, uncertainty, system complexity, steep learning curves, inadequate staff training, and the need for specialized technical skills hinder broader adoption. As AI technology evolves, <em>Generative AI</em> is emerging as a game changer by enabling intuitive, natural language interactions with complex systems, thereby making AI more accessible. This paper explores emerging AI topics, examines key challenges in deploying AI-based tools, highlights new opportunities, and presents practical examples of AI integration in water system operations. It also identifies critical aspects that the water research community must prioritize to advance water system research into the AI era, including promoting responsible and user-centered AI solutions, building trust in technology, integrating AI into existing workflows, enhancing data privacy and security, and strengthening partnerships.","PeriodicalId":443,"journal":{"name":"Water Research","volume":"28 1","pages":""},"PeriodicalIF":12.8,"publicationDate":"2024-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142789853","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":"Deciphering the link between particulate organic matter molecular composition and lake eutrophication by FT-ICR MS analysis","authors":"Minli Guo, Mingxing Yu, Xu Wang, Naidong Xiao, Arnaud Huguet, Yunlin Zhang, Guanglong Liu","doi":"10.1016/j.watres.2024.122936","DOIUrl":"https://doi.org/10.1016/j.watres.2024.122936","url":null,"abstract":"Eutrophication has emerged as a significant environmental problem for global lakes. As an essential carrier of nutrients, particulate organic matter (POM) plays a vital role in the eutrophication process of these aquatic systems. In this study, POM from seven lakes with different trophic states in the middle and lower reaches of the Yangtze River (China) was characterized using carbon and nitrogen stable isotopes and Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). The aim was to elucidate the relationship between the source and molecular composition of POM during the eutrophication process of lakes. The results indicated that POM was mainly composed of autochthonous (62.7%) and allochthonous (37.3%) sources, with the contribution from autochthonous sources being more pronounced across the different sources. The POM formulas mainly consisted of the subclasses CHO, CHON, CHOP, CHOS, and CHONS. Notably, CHOP formulas had the highest proportion of labile formula compounds, according for 51.56%. The unsaturation, aromaticity, and oxidation of unique POM formulas gradually decreased with increasing trophic states. A significant positive correlation was observed between CHOP and the percentage of labile compounds (MLB_L%) in unique POM formulas. The relative abundance of lipid and protein compounds of unique POM formulas showed a positive correlation with lake trophic states, which indicated that with the increase of lake trophic states, the content of autochthonous POM gradually increased. Herein, we inferred that with the intensification of lake eutrophication, the autochthonous POM increased, which was accompanied by a further increase of labile P-containing compounds in POM, thus leading to the increasing eutrophication process of lakes in the form of positive feedback. Overall, this investigation of POM at the molecular level illustrates the deep-rooted mechanism of frequent lake eutrophication. This is of great significance in understanding the fate of POM and effectively controlling lake eutrophication.","PeriodicalId":443,"journal":{"name":"Water Research","volume":"18 1","pages":""},"PeriodicalIF":12.8,"publicationDate":"2024-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142789861","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":"Enhancing Rejection of Short-chain Per- and Polyfluoroalkyl Substances by Tailoring the Surface Charge of Nanofiltration Membranes","authors":"Yue Zhi, Xiaoqing Zhao, Ao Shuai, Yonghui Jia, Xinyi Cheng, Shihong Lin, Feng Xiao, Le Han, Hongxiang Chai, Qiang He, Caihong Liu","doi":"10.1016/j.watres.2024.122931","DOIUrl":"https://doi.org/10.1016/j.watres.2024.122931","url":null,"abstract":"Nanofiltration (NF) effectively removes per- and polyfluoroalkyl substances (PFAS) from water but struggles with short-chain PFAS (i.e., those containing less than 6 perfluorinated carbons) due to size exclusion inefficiency. In this study, we developed layer-by-layer assembled NF membranes with PDADMAC/PSS terminal bilayers varying in chain lengths, hydrophilicity, and charge, and systematically assessed their removal of 16 representative PFAS species. The mechanisms between long-chain and short-chain PFAS were investigated and optimal strategies for enhancing PFAS selectivity were developed. Results demonstrated that the (PDADMAC/PSS)₃ membrane achieved the highest removal (86.1%-98.1%) for short-chain PFAS, including PFBA-PFHpA (C4-C6), PFBS (C4), PFMOPrA (C3), PFMOBA (C4), and GenX (C5), while effectively removing (&gt;99.9%) long-chain counterparts (C7-8). As feed water pH increased from 3.5 to 9, average PFAS rejection rose from 16.6% to 32.0%, revealing more negative charged membrane surface endow stronger electrostatic repulsion, particularly for short-chain anionic PFAS. In addition, we also tested the PFAS removal efficacy of (PDADMAC/PSS)₃ membrane using real sewage plant effluent. Compared to the pristine membrane, the (PDADMAC/PSS)₃ membrane exhibited improved removal for most PFAS, with removal efficiencies ranging from 82.54% for PFOA to 96.71% for PFOS. The most significant improvements were observed in C4 compounds like PFBA and PFBS (increased by 6.0-11.5%). Our study suggests that PFAS removal efficiency by NF highly depends on size exclusion, with short-chain anionic PFAS more likely affected by electrostatic repulsion. Membrane surface manipulation can enhance selectivity, aiding in predicting NF treatment effectiveness for specific PFAS compounds.","PeriodicalId":443,"journal":{"name":"Water Research","volume":"52 1","pages":""},"PeriodicalIF":12.8,"publicationDate":"2024-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142789850","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}