Water Research最新文献

{"title":"The association between estrogenic activity evolution and the formation of different products during the photochemical transformation of parabens in water","authors":"Xiaolin Niu ,&nbsp;Guanhui Chen ,&nbsp;Na Luo ,&nbsp;Mei Wang ,&nbsp;Mei Ma ,&nbsp;Xinping Hui ,&nbsp;Yanpeng Gao ,&nbsp;Guiying Li ,&nbsp;Taicheng An","doi":"10.1016/j.watres.2025.123236","DOIUrl":"10.1016/j.watres.2025.123236","url":null,"abstract":"<div><div>Photochemical transformation is a critical factor influencing the environmental fate of pharmaceutical and personal care products in aquatic ecosystems. However, the relationship between toxicity evolution and the formation of various transformation products has been seldom explored. This study investigates the behavior and changes in estrogenic activity during the photochemical transformation of a series of typical endocrine-disrupting parabens (PBs), focusing on the effects of increasing alkyl-chain length (MPB, EPB, PPB and BPB). Based on MS/MS analysis, four types of transformation products were identified: (1) <em>p</em>-hydroxybenzoic acid (HB), which exhibits no estrogenic activity; (2) hydroxylated products (OH-PBs); (3) dimer products formed between HB and PBs (HB-PBs); and (4) dimer products formed from identical PBs (PBs-PBs), comprising three distinct isomers. In the absence of standard sample, OH-PBs were synthesized and their estrogenic activity was evaluated using a yeast two-hybrid reporter assay. The EC₅₀ values were determined to be &lt;1 × 10^–3 M for OH-MPB, 2.05 × 10^–4 M for OH-EPB, 5.05 × 10^–5 M for OH-PPB, and 1.89 × 10^–5 M for OH-BPB. These indicate that the estrogenic activity of OH-PBs is one order of magnitude lower than that of the corresponding PBs. Both HB-PBs and the three isomers of PBs-PBs exhibited significantly higher estrogenic activities than their corresponding parent compounds, increasing 9 – 14 and 32 − 184 times, respectively, based on theoretical calculations. Among the three PBs-PBs isomers, the highest estrogenic activity was observed in the ether dimer, followed by the biphenyl dimers. Consistent with the parent compounds, the estrogenic activities of OH-PBs, HB-PBs, and PBs-PBs increased with the length of the alkyl-chain. The estrogenic activity of MPB and EPB followed an overall downward trend during the photochemical transformation, whereas PPB and BPB remained stable initially before declining rapidly. This behavior was associated with the contributions of toxic transformation products. These findings elucidate the relationship between molecular structure, transformation products, and estrogenic activity, highlighting the importance of understanding estrogenic activity evolution during the photochemical transformation of PBs.</div></div>","PeriodicalId":443,"journal":{"name":"Water Research","volume":"276 ","pages":"Article 123236"},"PeriodicalIF":11.4,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143071431","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":"Recovery of sulfur, generation of electricity and hydrogen peroxide from sulfion-rich wastewater using a novel self-driving photocatalytic fuel cell","authors":"Yong Chen ,&nbsp;Yong Liu ,&nbsp;Xiaobo Gong ,&nbsp;Jianlong Wang","doi":"10.1016/j.watres.2025.123232","DOIUrl":"10.1016/j.watres.2025.123232","url":null,"abstract":"<div><div>A novel photocatalytic fuel cell (PFC) with a sandwich-structure photoanode (ZnS@ZnO/ITO) was fabricated through electrodeposition-calcination to modulate the behavior of charge carriers and improve S^2- oxidation performance, which can effectively recover sulfur and generate electricity and hydrogen peroxide (H₂O₂) from sulfion-rich wastewater. ZnO was locate between ZnS and ITO in ZnS@ZnO/ITO to promote the separation of charge carriers and electron transfer, which can function as an electron transport bridge by forming a type-II heterostructure and acting as an electron transport layer. The PFC system was assembled by integrating ZnS@ZnO/ITO as the photoanode for S^2- oxidation, and graphite (Gr) as the cathode for oxygen reduction, given that Gr exhibits excellent catalytic activity for H₂O₂ generation. In the PFC, the removal efficiency of S^2-, H₂O₂ production, and the maximum power density were 93.4 %, 2.1 mmol/L, and 260 mW/m², respectively. After 24 cycles, the removal efficiency of S^2- and H₂O₂ production maintained 80.0 % and 1.6 mmol/L, respectively. The mechanism for sulfur recovery along with electricity generation and H₂O₂ production was proposed. Moreover, this PFC can effectively treat the actual shale gas wastewater and tannery wastewater, achieving the dual roles of wastewater treatment and resource recovery. This work opens up a brand-new avenue on PFC for purifying wastewater, meanwhile generating electricity and producing H₂O₂.</div></div>","PeriodicalId":443,"journal":{"name":"Water Research","volume":"275 ","pages":"Article 123232"},"PeriodicalIF":11.4,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143071605","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":"Fluoride-induced stress shapes partial denitrification granules to sustain microbial metabolism","authors":"Shenbin Cao ,&nbsp;Jinxin Fang ,&nbsp;Konrad Koch ,&nbsp;Xiaoyan Fan ,&nbsp;Hussein E. Al-Hazmi ,&nbsp;Rui Du ,&nbsp;George F Wells","doi":"10.1016/j.watres.2025.123239","DOIUrl":"10.1016/j.watres.2025.123239","url":null,"abstract":"<div><div>The presence of fluoride ions (F^-) in nitrogen-rich wastewater from photovoltaic and semiconductor industries introduces a significant challenge to biological treatment processes, particularly for the innovative partial denitrification (PD) process, which supplies nitrite for anaerobic ammonium oxidation (Anammox). This study provides the first comprehensive and systematic investigation of the effects of F^- stress on the granule-based PD process through batch tests and long-term operation. Results indicate that PD activity remains resilient to F^- shock up to 1.5 g/L but is markedly impaired at concentrations of 2.0–3.0 g/L, despite maintaining a nitrate-to-nitrite transformation ratio (NTR) of approximately 80 %. Under long-term F^- stress at 0.5 g/L, NTR gradually reduces to 50 %, but subsequently recovers to and maintains at 70 %. The increased secretion of loosely bound extracellular polymeric substances and proteins likely enhances the resistance of PD granules to F^- stress, though excessive amounts degrade their settling properties. F^--induced microbial community succession shapes a predominance of medium granules (1.0 &lt; d &lt; 2.0 mm of 60.2 %) by enhancing aggregation of smaller granules and disintegration of larger ones. This enhances the mechanical strength and microbial activity of PD granules, aiding in resistance to F^- stress to sustain microbial metabolism. Thauera is selectively enriched under long-term F^- stress, with upregulated nirBDS genes contributing to the reduced NTR. Additionally, increased electron metabolism activity and a robust antioxidative response help to maintain higher microbial metabolic activity, mitigating F^--induced oxidative stress. These findings advance our understanding of the resilience and adaptability of the PD process under F^- stress, providing critical insights for optimizing biological wastewater treatment systems in challenging environments.</div></div>","PeriodicalId":443,"journal":{"name":"Water Research","volume":"275 ","pages":"Article 123239"},"PeriodicalIF":11.4,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143071485","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":"The transition from macrophyte-dominated to algae-dominated lake systems enhances arsenic release from sediments","authors":"Xiangyu He ,&nbsp;Wenming Yan ,&nbsp;Xiang Chen ,&nbsp;Yan Wang ,&nbsp;Minjuan Li ,&nbsp;Qi Li ,&nbsp;Junliang Jin ,&nbsp;Zhongbo Yu ,&nbsp;Tingfeng Wu","doi":"10.1016/j.watres.2025.123233","DOIUrl":"10.1016/j.watres.2025.123233","url":null,"abstract":"<div><div>Declining macrophytes in eutrophic lakes are altering material cycling in sediments. However, the transformation of arsenic (As) in response to these changes remains poorly understood. In this study, high-resolution dialysis was used to measure dissolved As in sediments from macrophyte-dominated (MD) and algae-dominated (AD) zones across different seasons. The relationship between sedimentary As fractionation and environmental variations was analyzed, and the As transformation process was explored. Results showed that the shift from macrophyte- to algae-dominated zones enhanced As release in sediments. Dissolved As in pore water of AD peaked at 120.36 μg/L in summer, exhibiting the highest release intensity, while MD showed a notable As release profile in spring (34.92 μg/L). In spring, decomposition and acidification of macrophyte residues, along with organic matter (OM) complexation, promoted the release of adsorbed As in MD. In contrast, reduction and dissolution of iron (Fe) oxides, along with competition for adsorption sites by dissolved phosphorus (P), drove As release in AD during summer. The high humification and low redox potential in MD sediments in summer promoted As-S co-precipitation, leading to As sequestration instead of release, this contrasts with the common view that warmer temperatures favor As release from sediments. The conversion from macrophytes to algae in eutrophic lakes may exacerbate the risk of As release, warranting further investigation.</div></div>","PeriodicalId":443,"journal":{"name":"Water Research","volume":"276 ","pages":"Article 123233"},"PeriodicalIF":11.4,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143071488","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":"Insight into the characterization of dissolved organic matter in shallow lakes with different trophic states and their net photo-generation capacity of reactive oxygen species","authors":"Xiaolu Li ,&nbsp;Zhen Hu ,&nbsp;Minli Guo ,&nbsp;Guanglong Liu ,&nbsp;Jiong Gao ,&nbsp;Wei Xing","doi":"10.1016/j.watres.2025.123204","DOIUrl":"10.1016/j.watres.2025.123204","url":null,"abstract":"&lt;div&gt;&lt;div&gt;Reactive oxygen species (ROS) are ubiquitous in the aquatic environment, and they are closely related to several biogeochemical processes. Dissolved organic matter (DOM) is one of the main photosensitizers involved in the formation of ROS and it also serves as a sink for ROS by involving in scavenging, quenching, and antioxidant reactions. The net effect of these processes depends on the concentration, source, and composition of the DOM. Current studies have mainly focused on the steady-state concentration of reactive oxygen species ([ROS]&lt;sub&gt;ss&lt;/sub&gt;) produced by the total DOM in lakes with different trophic states and ignored the net photo-generation capacity of ROS ([ROS]&lt;sub&gt;DOM&lt;/sub&gt;, the net steady concentration of ROS generated per unit mass of DOM), leading to a vague understanding of the photochemical properties of DOM in aquatic systems, especially in shallow lakes with different trophic states. In this study, the optical composition of DOM was determined with optical characterization, such as specific UV–Vis and excitation-emission matrices with fluorescence regional integration (FRI-EEMs), and its molecular characteristics were analyzed by Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR MS). The results revealed that DOM in lakes with different trophic states had mixed endogenous and exogenous characteristics, accompanied by an increasing trend in endogenous characteristics with the increasing trophic state of lakes. Spectroscopic probes were used to detect the steady-state concentration of ROS and further calculate the [ROS]&lt;sub&gt;DOM&lt;/sub&gt;, such as [&lt;sup&gt;3&lt;/sup&gt;DOM*]&lt;sub&gt;DOM&lt;/sub&gt;, [&lt;sup&gt;•&lt;/sup&gt;OH]&lt;sub&gt;DOM&lt;/sub&gt;, [&lt;sup&gt;1&lt;/sup&gt;O&lt;sub&gt;2&lt;/sub&gt;]&lt;sub&gt;DOM&lt;/sub&gt; and [O&lt;sub&gt;2&lt;/sub&gt;&lt;sup&gt;.-&lt;/sup&gt;]&lt;sub&gt;DOM&lt;/sub&gt;. The results indicated that the [ROS]&lt;sub&gt;DOM&lt;/sub&gt; in lakes with light-eutrophic states was significantly higher than that in lakes with moderate-eutrophic and hyper-eutrophic states, which indicated that the DOM in lower trophic state lakes has a higher net photo-generation capacity of ROS. Pearson analysis results showed that [&lt;sup&gt;3&lt;/sup&gt;DOM*]&lt;sub&gt;DOM&lt;/sub&gt;, [&lt;sup&gt;•&lt;/sup&gt;OH]&lt;sub&gt;DOM&lt;/sub&gt;, [&lt;sup&gt;1&lt;/sup&gt;O&lt;sub&gt;2&lt;/sub&gt;]&lt;sub&gt;DOM&lt;/sub&gt; and [O&lt;sub&gt;2&lt;/sub&gt;&lt;sup&gt;.-&lt;/sup&gt;]&lt;sub&gt;DOM&lt;/sub&gt; had a significant positive correlation with lignin/CRAMs-like, aromatic, and tannin compounds, as well as the fluorescence components, fulvic- and humic-like substances and the UV–Vis indicator: SUVA&lt;sub&gt;254&lt;/sub&gt; revealed that DOM with higher humification and aromaticity had a higher net photo-generation capacity of ROS in different trophic state lakes. In addition, the molecular uniqueness of the DOM was dominated by lignin/CRAMs-like and aromatic compounds, which were positively correlated with [ROS]&lt;sub&gt;DOM&lt;/sub&gt;, in the following order: [&lt;sup&gt;3&lt;/sup&gt;DOM*]&lt;sub&gt;DOM&lt;/sub&gt; &gt; [&lt;sup&gt;•&lt;/sup&gt;OH]&lt;sub&gt;DOM&lt;/sub&gt; &gt; [&lt;sup&gt;1&lt;/sup&gt;O&lt;sub&gt;2&lt;/sub&gt;]&lt;sub&gt;DOM&lt;/sub&gt; &gt; [O&lt;sub&gt;2&lt;/sub&gt;&lt;sup&gt;.-&lt;/sup&gt;]&lt;sub&gt;DOM&lt;/sub&gt;. This study emphasizes the im","PeriodicalId":443,"journal":{"name":"Water Research","volume":"276 ","pages":"Article 123204"},"PeriodicalIF":11.4,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143071930","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 metabolic enzymes, pathways and microbial hosts for co-metabolic degradation of organic micropollutants in wastewater","authors":"Boyu Lyu ,&nbsp;Bharat Manna ,&nbsp;Xueyang Zhou ,&nbsp;Ivanhoe K.H. Leung ,&nbsp;Naresh Singhal","doi":"10.1016/j.watres.2025.123229","DOIUrl":"10.1016/j.watres.2025.123229","url":null,"abstract":"<div><div>Organic micropollutants (OMPs) in wastewater present significant environmental challenges, but effective removal strategies are hindered by our limited understanding of their co-metabolic biodegradation. We aim to elucidate the microbial enzymes, metabolic pathways, and community members involved in OMP co-metabolic degradation, thereby paving the way for more effective wastewater treatment strategies. We integrated multi-omics (metagenomics, metaproteomics, and metabolomics) and functional group analysis to investigate 24 OMPs under three aeration conditions. Our findings reveal that oxidoreductases, particularly cytochrome P450s and peroxidases, are crucial for recalcitrant OMPs containing halogen groups (-Cl, -F) like fluoxetine and diuron. Hydrolases, including amidases, are instrumental in targeting amide-containing (-CONH₂) OMPs such as bezafibrate and carbamazepine. Regarding microbial metabolism involved in OMP co-metabolic degradation, we found that amino acid metabolism is crucial for degrading amine-containing (-NH₂) OMPs like metoprolol and citalopram. Lipid metabolism, particularly for fatty acids, contributes to the degradation of carboxylic acid (-COOH) containing OMPs such as bezafibrate and naproxen. Finally, with <em>Actinobacteria, Bacteroidetes</em>, and <em>Proteobacteria</em> emerging as primary contributors to these functionalities, we established connections between OMP functional groups, degradation enzymes, metabolic pathways, and microbial phyla. Our findings provide generalized insights into structure-function relationships in OMP co-metabolic degradation, offering the potential for improved wastewater treatment strategies.</div></div>","PeriodicalId":443,"journal":{"name":"Water Research","volume":"276 ","pages":"Article 123229"},"PeriodicalIF":11.4,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143071689","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fluorine recovery from low-concentration fluorine wastewater by flow-electrode capacitive deionization and fluid bed crystallization (FCDI-FBC): Preconcentration and high-quality fluorite pellets formation","authors":"Jing Yang ,&nbsp;Hui Gong ,&nbsp;Shuqian Chai ,&nbsp;Danyang Zhu ,&nbsp;Kejin Chen ,&nbsp;Qinpei Liu ,&nbsp;Xiaoguang Liu ,&nbsp;Xiaohu Dai","doi":"10.1016/j.watres.2025.123228","DOIUrl":"10.1016/j.watres.2025.123228","url":null,"abstract":"<div><div>Fluorine (F), critical for various industries, faces resource scarcity due to limited reserves of its primary source, fluorite (CaF₂). While fluorine-containing wastewater from industrial processes represents a valuable potential resource, recovering fluorine from low-concentration wastewater remains challenging. This study introduces a cyclic \"preconcentration + recovery\" system combining flow-electrode capacitive deionization (FCDI) and fluidized bed crystallization (FBC) to address this gap. FCDI preconcentrates fluorine ions into high-concentration brine, and FBC facilitates the formation of high-purity fluorite crystals. Experimental parameters influencing FCDI efficiency - such as influent fluoride concentration, electrode solution composition, and flow rate - were systematically evaluated. Additionally, the cyclic operation was modeled to enhance the whole recovery rate across multiple cycles. The experimental results demonstrated that FCDI achieves an 83.90% fluoride removal rate under optimal conditions with energy-efficient operation. FBC produces fluorite crystals of up to 97.20% purity, classified as acid-grade. The integrated FCDI-FBC system achieves a fluoride recovery rate of 64.40% in single operation mode, with further improvements in cyclic mode. The proposed system offers a sustainable and economically feasible solution to fluorine recovery from low-concentration wastewater, representing a significant step toward the sustainable utilization of non-renewable fluorite resources.</div></div>","PeriodicalId":443,"journal":{"name":"Water Research","volume":"275 ","pages":"Article 123228"},"PeriodicalIF":11.4,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143071690","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":"Evaluating the impact of underwater skimming on slow sand filter performance and operation","authors":"Tolulope Elemo ,&nbsp;Michael Chipps ,&nbsp;Nigel Graham ,&nbsp;Andrew Turner ,&nbsp;Sophie Bretagne ,&nbsp;Bruce Jefferson ,&nbsp;Francis Hassard","doi":"10.1016/j.watres.2025.123234","DOIUrl":"10.1016/j.watres.2025.123234","url":null,"abstract":"<div><div>Conventional cleaning of slow sand filters (SSFs) requires the beds to be drained before a layer of media and the <em>Schmutzdecke</em> are removed, called ‘dry skimming’ (DS), which can result in significant downtime. An alternative is proposed whereby the filter is skimmed whilst still submerged, called ‘underwater skimming’ (UWS). Previous attempts to avoid draining the bed have led to concerns about the risks of UWS in terms of headloss development, particle penetration, and microbial water quality. In this study, pilot scale SSFs, cleaned by either DS or UWS, were operated concurrently, to compare and assess the potential risks of UWS in terms of filtrate quality, microbial removal, and recovery following skimming. While all filters exhibited effective turbidity removal (0.04–0.9 NTU turbidity from outlet), UWS filters had improved performance immediately after cleaning compared to DS in terms of recovery of filtrate microbial water quality. Specifically, total coliforms in the UWS filter outlets, in the first seven days post-skimming, ranged from 1 to 109 most probable number (MPN)/mL, compared to 1 to 1414 MPN/mL for DS filters. Both methods yielded satisfactory headloss recovery, indicative of limited particle penetration at depth, and effective cleaning. Exploring different sweetening flow rates during UWS revealed no observable differences in headloss, turbidity reduction, or microbial quality between the flow rates tested. <em>Schmutzdecke</em> microbial community was similar irrespective of cleaning method and was governed instead by seasonal changes and the ripening process. The improved microbial removal afforded by UWS provides a means of significantly improving water productivity and enabling options for much better utilisation of SSFs.</div></div>","PeriodicalId":443,"journal":{"name":"Water Research","volume":"276 ","pages":"Article 123234"},"PeriodicalIF":11.4,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143071486","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Patterns and controls of rare earth element (REE) dynamics across a boreal stream network","authors":"Martin Škerlep ,&nbsp;Hjalmar Laudon ,&nbsp;Fredrik Lidman ,&nbsp;Emma Engström ,&nbsp;Ilia Rodushkin ,&nbsp;Ryan A. Sponseller","doi":"10.1016/j.watres.2025.123237","DOIUrl":"10.1016/j.watres.2025.123237","url":null,"abstract":"<div><div>Increased demand for rare earth elements (REE) has resulted in their increased exploitation and the need to better understand their cycling in aquatic environments. Thus far much of the research in boreal areas focused on REE cycling in larger rivers, while relatively little is known regarding their mobilization in smaller headwater streams. Here we used the Krycklan Catchment Study in northern boreal Sweden to investigate how REE are mobilized from diverse boreal headwaters and how their catchment exports are influenced by processes such as weathering, hydrology, and complexation with other solutes. We found that wetland dominated headwaters were source limited and prone to dilution during high discharge, while forested headwaters had considerably higher total REE concentrations and were less affected by discharge fluctuations. Larger downstream catchments showed clear discharge driven seasonal patterns, with high concentrations during spring flood and low concentrations during base flow. While the proportion of mineral soils and water travel time in the catchment were important predictors of REE mobilization, complexation with organic matter appears to play a greater role in higher-order streams with higher pH and a larger contribution from deeper groundwater sources. Overall, we highlight the stark differences between REE cycling in the headwaters and in higher order streams, which can provide important information on the processes that mobilize REE from catchments.</div></div>","PeriodicalId":443,"journal":{"name":"Water Research","volume":"276 ","pages":"Article 123237"},"PeriodicalIF":11.4,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143071487","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Recent advances and challenges in mechanistic modelling of photosynthetic processes for wastewater treatment","authors":"S. Rossi, G Capson-Tojo, A. Sànchez-Zurano, D. Carecci, D.J. Batstone, G. Acìén-Fernandez, E. Ficara","doi":"10.1016/j.watres.2025.123216","DOIUrl":"https://doi.org/10.1016/j.watres.2025.123216","url":null,"abstract":"Phototrophy-based wastewater treatment has the potential to reduce wastewater bioremediation costs, improving environmental impacts and allowing for enhanced resource recovery. Microbial interactions occurring in phototrophic-chemotrophic consortia treating wastewater are particularly complex, and with varying impact on each clade by different chemical, biological and physical, including light—related factors. For this reason, mechanistic mathematical modelling of these systems is challenging, and the resulting models are especially complex. In this work, we focus particularly on the extension of microalgae-focused models to simulation of phototrophic-chemotrophic systems, especially as for (i) microalgae-bacteria and (ii) purple bacteria-enriched communities. The review identifies model structures and typical modelling choices, as well as the potential applications and limitations of available experimental protocols for model calibration, identifying relevant research needs and requirements. Simplified models have been proposed, which allows assessment of dominating mechanisms, but may not represent more complex behaviour, including nutrient removal and response to light cycling, and have been largely applied to simple (oxygen and carbon dioxide) exchange between algae and aerobic heterotrophs. More comprehensive models including all relevant microbial clades have been recently published, which consider nutrient cycling, competitive uptake, and other features, including temperature, pH, and gas transfer. These models have comparable structures but can be difficult to compare in a quantitative manner, often due to different fundamental stoichiometry (e.g., in the assumed algae composition), or in differing approaches to storage compounds. Particularly for models with a high complexity, it is often difficult to properly estimate biokinetic species-specific parameters for the different phototrophic and chemotrophic populations involved. Several methods have been proposed for model calibration, among which photo-respirometry has shown high potential. Photo-respirometric methods do not follow a standardised approach, which has limited their application and comparability between studies. Finally, the validation of models on long term data sets, demonstrating the impact of seasonality, as well as long term population adaptation is rare.","PeriodicalId":443,"journal":{"name":"Water Research","volume":"11 1","pages":""},"PeriodicalIF":12.8,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143071691","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}