Environmental Science: Processes & Impacts最新文献

{"title":"Characterization of the binding process between gallic acid and trivalent chromium in tannery wastewater: a spectroscopic perspective†","authors":"Situ Mu, Qi Yang, Chenxu Yan, Tong Xu, Jing Zhang, Junjun Ma and Chun Liu","doi":"10.1039/D4EM00621F","DOIUrl":"10.1039/D4EM00621F","url":null,"abstract":"<p >Trivalent chromium (Cr<small>³⁺</small>) is a heavy metal widely present in tannery wastewater, and organic ligands represented by gallic acid (GA) have significant effects on the environmental behavior of Cr<small>³⁺</small>. This study explored the binding process of Cr<small>³⁺</small> with GA through the integration of ultraviolet-visible (UV-vis), Fourier transform infrared (FTIR), and fluorescence spectroscopy coupled with two-dimensional correlation analyses (2DCOS). UV-vis results showed that the average molecular weight of the solutions gradually increased with the addition of Cr<small>³⁺</small> ions. The vibration of FTIR characteristic peaks indicated that the hydroxyl and carboxyl functional groups of GA were complexed with Cr<small>³⁺</small> ions. On the basis of the fluorescence quenching of GA after the addition of Cr<small>³⁺</small> ions, the complexation coefficient was calculated as 4 × 10<small>⁴</small>. 2DCOS and nuclear magnetic resonance (NMR) spectra demonstrated the binding sequence of GA with Cr<small>³⁺</small> as <em>meta</em>-hydroxyl groups → carboxyl groups → <em>para</em>-hydroxyl groups, and heterospectral 2DCOS showed that the intensity change in UV-vis absorption bands occurred before that in IR absorption bands. Density functional theory (DFT) was used to quantify the binding energy of GA with Cr<small>³⁺</small> at different binding sites, and it was shown that the binding energy of the <em>meta</em>-hydroxyl group was the lowest. Overall, this study provides a new approach to the analysis of the molecular structure of complexes and the binding process between organic ligands and metal ions in wastewater.</p>","PeriodicalId":74,"journal":{"name":"Environmental Science: Processes & Impacts","volume":" 2","pages":" 453-462"},"PeriodicalIF":4.3,"publicationDate":"2025-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142996505","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Optical properties and photobleaching of wildfire ashes aqueous extracts†","authors":"Frank Leresche, Sarah J. Fischer, Shelby Buckley and Fernando L. Rosario-Ortiz","doi":"10.1039/D4EM00626G","DOIUrl":"10.1039/D4EM00626G","url":null,"abstract":"<p >Wildfires can severely degrade soils and watersheds. Post-fire rain events can leach ashes and altered dissolved organic matter (DOM) into streams, impacting water quality and carbon biogeochemistry. The photochemical properties and persistence of DOM from wildfire ash leachates are not well understood. To establish a range of properties, wildfire DOM leachates were generated from (i) surficial [grey and black] wildfire ashes, (ii) mineral soils below ash, and (iii) unimpacted soils from two Colorado wildfire scars. Subsequently, the leachates were studied under simulated sunlight. Photochemical properties of absorbance, fluorescence and <small>¹</small>O<small>₂</small> quantum yield (<em>Φ</em><small>_F</small> and <em>Φ</em><small>_{<small>¹</small>O<small>₂</small>}</small>) were determined for thirteen wildfire leachates. <em>Φ</em><small>_{<small>¹</small>O<small>₂</small>}</small> of ash leachates was greatest (7.6 ± 3.4%), followed by underlying mineralized soil leachates (4.6 ± 0.7%), and control soil leachates (Φ<small>_{<small>¹</small>O<small>₂</small>}</small> = 3.9 ± 1%). Correlations between increasing <em>E</em><small>₂</small> : <em>E</em><small>₃</small>, <em>Φ</em><small>_F</small>, <em>Φ</em><small>_{<small>¹</small>O<small>₂</small>}</small> suggest that surface ash leachates with elevated molar absorptivity may play an important role in <small>¹</small>O<small>₂</small> production that is not well documented. Interestingly, photobleaching experiments comparing ash DOM to unimpacted soil DOM revealed ash leachates lost fluorescence, absorbance, while producing CO<small>₂</small> at rates ∼3 fold greater than soils. This suggests that aromatic features of ashes may cause degradation of wildfire DOM faster than unimpacted DOM in the environment.</p>","PeriodicalId":74,"journal":{"name":"Environmental Science: Processes & Impacts","volume":" 2","pages":" 473-485"},"PeriodicalIF":4.3,"publicationDate":"2025-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/em/d4em00626g?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143044964","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Microcontaminants and microplastics in water from the textile sector: a review and a database of physicochemical properties, use in the textile process, and ecotoxicity data for detected chemicals†","authors":"Isabella Gambino, Elisa Terzaghi, Enrica Baldini, Giovanni Bergna, Giovanni Palmisano and Antonio Di Guardo","doi":"10.1039/D4EM00639A","DOIUrl":"10.1039/D4EM00639A","url":null,"abstract":"<p >Microcontaminants (MCs) and microplastics (MPs) originating from the textile sector are today receiving a great deal of attention due to potential environmental concerns. Environmental pressures and impacts related to the textile system include not only the use of resources (<em>e.g.</em>, water) but also the release of a wide variety of pollutants. This review's main objective is to highlight the presence of textile MCs and MPs in water, in their full path from textile factories (from raw materials to the final product) to wastewater treatment plants (WWTPs), and finally to the receiving surface waters. Their environmental fate and ecotoxicity were also addressed. Overall, more than 500 compounds were found, many of which are so called “contaminants of environmental concern” such as per- and polyfluoroalkyl substances (PFAS) and alkylphenol compounds. A database of physicochemical properties, ecotoxicity, and place of detection (specific textile process, WWTP, surface water or sediment) (classification by several international agencies) was compiled for the chemical detected. Preliminary risk assessment was conducted for those MCs for which the reported environmental concentrations exceeded the Predicted No Effect Concentration (PNEC). These chemicals were some nonylphenols, nonylphenol ethoxylates and organophosphate esters. Among MPs, polyester and nylon fibres were the most abundant. The highest concentration of MPs was reported in sludge (about 1.4 × 10<small>⁶</small> MPs per kg) compared to wastewater and surface water which showed MP concentrations at least two orders of magnitude lower. The role of transboundary contamination due to the release of chemicals from imported textile products was also assessed.</p>","PeriodicalId":74,"journal":{"name":"Environmental Science: Processes & Impacts","volume":" 2","pages":" 297-319"},"PeriodicalIF":4.3,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/em/d4em00639a?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142996508","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Fine particulate matter from burning oil and gas and associated neurological symptoms among Deepwater Horizon oil spill cleanup workers†","authors":"Christina L. Norris, Dale P. Sandler, Gregory C. Pratt, Mark R. Stenzel, Patricia A. Stewart, W. Braxton Jackson, Kate E. Christenbury, Emily J. Werder, Caroline P. Groth, Sudipto Banerjee, Kaitlyn G. Lawrence and Lawrence S. Engel","doi":"10.1039/D4EM00469H","DOIUrl":"10.1039/D4EM00469H","url":null,"abstract":"<p >Burning and flaring of oil and gas following the 2010 Deepwater Horizon (DWH) oil spill generated high airborne concentrations of fine particulate matter (PM<small>_2.5</small>). Neurological effects of PM<small>_2.5</small> have been previously reported, but this relationship has received limited attention in the context of oil spills. We evaluated associations between burning-related PM<small>_2.5</small> and prevalence of self-reported neurological symptoms during, and 1–3 years after, the DWH disaster cleanup. For 9914 DWH disaster responders in the Gulf Long-term Follow-up Study who worked on the water, we examined aggregate outcomes (central nervous system [CNS; dizziness, sweating, palpitations, nausea, or migraine/severe headache] and peripheral nervous system [PNS; tingling/numbness in extremities, blurred vision, or stumbling] symptoms) and individual symptoms (CNS and PNS symptoms, plus insomnia, vomiting, seizures, and fatigue). We estimated PM<small>_2.5</small> concentrations <em>via</em> Gaussian plume dispersion models and linked these to detailed DWH cleanup work histories. We used log-binomial regression to estimate adjusted prevalence ratios (PR) and 95% confidence intervals, accounting for age, race, ethnicity, and sex, and DWH disaster-related co-exposures to benzene, toluene, ethylbenzene, xylene, and <em>n</em>-hexane (BTEX-H). We examined effect measure modification by age, race, smoking, and BTEX-H exposure. During the disaster, 34% of participants experienced at least one symptom (23% CNS, 12% PNS); 1–3 years later, 30% did (19% CNS, 17% PNS). Evidence of associations with PM<small>_2.5</small> was most consistent for CNS symptoms (PR range: 1.17 to 1.51), although we did not observe exposure-response trends. For PNS, PR ranged from 0.96 to 1.84. Associations with PM were more apparent among those with lower BTEX-H exposure and among older workers. We found some evidence of an association between burning-related PM<small>_2.5</small> and prevalence of neurologic symptoms during the DWH disaster response and 1–3 years later. Understanding these relationships can inform responses to future disasters to better protect human health.</p>","PeriodicalId":74,"journal":{"name":"Environmental Science: Processes & Impacts","volume":" 2","pages":" 423-436"},"PeriodicalIF":4.3,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142996506","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Identification of dissipation pathways for pharmaceuticals in soils – a modelling approach†","authors":"Matthias Boeckmann, Jan Siemens, Benjamin Justus Heyde and Christiane Zarfl","doi":"10.1039/D4EM00777H","DOIUrl":"10.1039/D4EM00777H","url":null,"abstract":"<p >Concentrations of pollutants like pharmaceuticals in soils typically decrease over time, though it often remains unclear whether this dissipation is caused by the transformation of the pollutant or a decreasing extractability. We developed a mathematical model that (1) explores the plausibility of different dissipation pathways, and (2) allows the quantification of concentration differences between aqueous soil extracts and soil solution. The model considers soil particles as uniform spheres, kinetic sorption towards an equilibrium (Freundlich model), and two dissipation pathways, <em>i.e.</em> irreversible transformation and mineralization (following 1<small>^st</small> order kinetics) as well as the formation of non-extractable residues <em>via</em> intraparticle diffusion. Applying the model to 19 published datasets (eight pharmaceuticals, three soils) showed that intraparticle diffusion accounts for approximately two thirds of all simulated mass fluxes. Reversible formation of non-extractable residues could play a major role for dissipation, while irreversible transformation and mineralization cannot be excluded either based on the available datasets. The difference between concentrations in aqueous extracts and soil solution quantified by the model is below typical model and measurement uncertainties for most of the investigated pharmaceuticals. Larger differences might be linked to a positive ionic charge of the pollutant. The model helps in disentangling different dissipation pathways in soils and optimizing experiments elucidating the long-term fate of pollutants in soils.</p>","PeriodicalId":74,"journal":{"name":"Environmental Science: Processes & Impacts","volume":" 3","pages":" 649-660"},"PeriodicalIF":4.3,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/em/d4em00777h?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142996507","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Correction: Responses of CO2 and CH4 in the alpine wetlands of the Tibetan Plateau to warming and nitrogen and phosphorus additions","authors":"Wenbao Zhang, Huijuan Xin, Zongxing Li, Qiao Cui, Bin Xu, Biao Tang, Yaning Wang, Chong Xu and Jian Xue","doi":"10.1039/D5EM90001H","DOIUrl":"10.1039/D5EM90001H","url":null,"abstract":"<p >Correction for ‘Responses of CO<small>₂</small> and CH<small>₄</small> in the alpine wetlands of the Tibetan Plateau to warming and nitrogen and phosphorus additions’ by Wenbao Zhang <em>et al.</em>,<em>Environ. Sci.: Processes Impacts</em>, 2024, <strong>26</strong>, 1516–1525, https://doi.org/10.1039/D4EM00174E.</p>","PeriodicalId":74,"journal":{"name":"Environmental Science: Processes & Impacts","volume":" 2","pages":" 513-513"},"PeriodicalIF":4.3,"publicationDate":"2025-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/em/d5em90001h?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142976911","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"The INGENIOUS project: towards understanding air pollution in homes†","authors":"Nicola Carslaw, Jennifer Aghaji, Sri Hapsari Budisulistiorini, David C. Carslaw, Lia Chatzidiakou, Rachael W. Cheung, Terry J. Dillon, Pete Edwards, Denisa Genes, Chiara Giorio, Jacqueline F. Hamilton, Erika Ikeda, Roderic L. Jones, James Lee, Alastair C. Lewis, Ashish Kumar, Rosemary McEachan, Gordon McFiggans, Tim Murrels, Nicholas Pleace, Athina Ruangkanit, Yunqi Shao, Simon P. O'Meara, David R. Shaw, Marvin Shaw, Dagmar Waiblinger, Tom Warburton, Sarah West, Chantelle Wood and Tiffany Yang","doi":"10.1039/D4EM00634H","DOIUrl":"10.1039/D4EM00634H","url":null,"abstract":"<p >This paper provides an overview of the INGENIOUS (UnderstandING the sourcEs, traNsformations and fates of IndOor air pollUtantS) project, aiming to better understand air pollution in homes. Although our homes are the microenvironment in which we spend most of our time, we know relatively little about the sources, transformation processes and fates of indoor air pollutants, or our exposure to them. INGENIOUS aims to address this knowledge gap by delivering: an indoor emissions inventory for UK homes; comprehensive air pollutant measurements in 310 homes in Bradford using a combination of low cost-sensors and more advanced air quality instrumentation; an analysis of the impact of indoor air pollution on outdoor air quality and <em>vice versa</em> using mobile measurements; insight into future indoor air quality using detailed air pollution models; identification of indoor air pollutants that warrant further toxicological study; and better understanding of the barriers and facilitators for behaviour that drives improved indoor air quality. Median daily PM<small>_2.5</small> and CO<small>₂</small> concentrations varied from 7.8 μg m<small>⁻³</small> and 666 ppm in the summer, to 16.4 μg m<small>⁻³</small> and 857 ppm in the winter respectively in our sampled homes. Peak daily PM<small>_2.5</small> concentrations above 150 μg m<small>⁻³</small> were frequently observed across all seasons, and were driven by cooking. Cooking activities also generated high concentrations of volatile organic compounds during emissions measurements, such as harmful aldehydes (up to ∼50 ppb), and alcohols (up to ∼600 ppb) from a chicken stir-fry. Our sampled homes displayed a wide variation in indoor pollutant concentrations, with a strong link to behaviour, including frequency and type of cooking activities, and use of ventilation.</p>","PeriodicalId":74,"journal":{"name":"Environmental Science: Processes & Impacts","volume":" 2","pages":" 355-372"},"PeriodicalIF":4.3,"publicationDate":"2025-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/em/d4em00634h?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143031679","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Key role of persistent free radicals in soil for persulfate activation: impacts on benzo[a]pyrene degradation†","authors":"Yiwen Ou, Xintong Li, Shixu Feng and Hongxia Zhao","doi":"10.1039/D4EM00437J","DOIUrl":"10.1039/D4EM00437J","url":null,"abstract":"<p >Environmentally persistent free radicals (EPFRs) have been widely detected in polycyclic aromatic hydrocarbon (PAH)-contaminated soils, but the activation of persulfate by inherent EPFRs in PAH-contaminated soil for the transformation of PAHs remains unclear. In the present study, benzo[<em>a</em>]pyrene (B[<em>a</em>]P) was selected as a representative PAH and its transformation in a persulfate/B[<em>a</em>]P-contaminated soil system was studied without the addition of any other activator. Results indicated that EPFRs in the soil activated persulfate to produce reactive oxygen species (ROS) and degraded B[<em>a</em>]P. It was found that the decomposition of persulfate was accompanied with the decay of EPFRs in the soil, which was quantified using electron paramagnetic resonance (EPR) technique. Correspondingly, combined with EPR and quenching experiments, it was confirmed that sulfate radicals (SO<small>₄</small>˙<small>⁻</small>), hydroxyl radicals (˙OH), superoxide radicals (˙O<small>₂</small><small>⁻</small>) and singlet oxygen (<small>¹</small>O<small>₂</small>) coexist in the reaction system, and ˙O<small>₂</small><small>⁻</small> and <small>¹</small>O<small>₂</small> play major roles in the degradation of B[<em>a</em>]P. Primary intermediates were identified <em>via</em> gas chromatography-mass spectrometry (GC-MS), and the transformation pathway underlying B[<em>a</em>]P degradation was proposed. Furthermore, the acute and chronic toxicities of seven intermediates to aquatic organisms were predicted using Ecological Structure Activity Relationships (ECOSAR) software, and the corresponding results showed that the seven intermediates detected were very toxic to the environment. This study provides new insights into the activation of persulfate by EPFRs in the degradation of refractory pollutants.</p>","PeriodicalId":74,"journal":{"name":"Environmental Science: Processes & Impacts","volume":" 2","pages":" 390-400"},"PeriodicalIF":4.3,"publicationDate":"2025-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142968700","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Preliminary insight into the intracellular behaviour of rare earths and other technology-critical elements (TCEs) in northern pike liver: study of TCE-binding biomolecules via size-exclusion HPLC-ICP-MS†","authors":"Zrinka Dragun, Zoran Kiralj, Željka Fiket and Dušica Ivanković","doi":"10.1039/D4EM00674G","DOIUrl":"10.1039/D4EM00674G","url":null,"abstract":"<p >Technology-critical elements (TCEs) refer to the elements that play an important role in many emerging technologies and the production of advanced materials, and these include lanthanides, tungsten and vanadium. Actinides, Tl, and Pb, which also belong to TCEs, are abundantly used in power generation, industrial applications, and modern agricultural practices. The information on the influence of these elements on the aquatic environment and biota is still rather scarce. Thus, the distributions of the above-mentioned metals among cytosolic biomolecules of different molecular masses in the liver of the northern pike (<em>Esox lucius</em>) from the Mrežnica River (Croatia) were studied to obtain an insight into their intracellular behaviour and potential for toxicity. The applied method was a hyphenated system of size-exclusion high-performance liquid chromatography and inductively coupled plasma mass spectrometry. In the samples with lower cytosolic concentrations, the obtained distributions of several TCEs (lanthanides, W, Th, and U) and Pb, among biomolecules of a wide range of molecular masses, which covered the entire column separation range (&lt;10 to &gt;600 kDa), indicated their nonspecific binding to various intracellular components. In the sample with the highest cytosolic concentration, a shift towards the highest molecular masse (&gt;600 kDa) was observed for lanthanides and actinides, which is a sign of their possible binding to protein aggregates. In contrast, W and Pb showed a preference for medium molecular mass biomolecules (30–100 kDa). Moreover, it was hypothesized that prominent elution of U and Pb observed in the low molecular mass region (&lt;10 kDa) possibly indicated their partial detoxification. Potential Pb associations with metallothionein-like proteins were also recorded (∼6–7 kDa). The remaining two elements, V and Tl, exhibited more specific intracellular binding, as they were eluted within one/two narrow peaks in the high molecular mass region (575 kDa/100–400 kDa). The tendency of the studied TCEs and other potentially toxic elements to bind to medium and high molecular mass intracellular proteins necessitates further research of their specific targets.</p>","PeriodicalId":74,"journal":{"name":"Environmental Science: Processes & Impacts","volume":" 1","pages":" 262-276"},"PeriodicalIF":4.3,"publicationDate":"2025-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/em/d4em00674g?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142941679","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Dissolved phosphorous through dry–wet–dry transitions in a small-dammed river basin: integrated understanding on transport patterns, export controls, and fate†","authors":"H. K. M. Mihiranga, Yan Jiang, M. G. S. Sathsarani and Xuyong Li","doi":"10.1039/D4EM00686K","DOIUrl":"10.1039/D4EM00686K","url":null,"abstract":"<p >An integrated understanding of dissolved phosphorous (DP) export mechanism and controls on export over dry and wet periods is crucial for riverine ecological restorations in dammed river basins considering its high bioavailability and retention rates at dams. Riverine DP transport patterns (composition, sources, and transport pathways), export controls, and fate were investigated over the 2020 wet season (5 events) and dry seasons before and after it (2 events: dry<small>_(before)</small> and dry<small>_(after)</small>) in a semi-arid, small-dammed watershed to comprehend the links between terrestrial DP sources and aquatic DP sinks. Close spatiotemporal monitoring of the full range of phosphorous and total suspended solids (TSSs) and subsequent analyses (hysteresis, hierarchical partitioning, and coefficient of variation) provided the basis for the study. Total-DP (TDP) shared 13–39% (25%) of total-P (TP) through storms, dissolved organic-P (DOP) shared 6–21% (12%), and phosphate-P shared (PO<small>₄</small>-P) 7–22% (13%). DP forms displayed strong connections with discharge trends across the wet season, and marked changes in the shares were reported over dry–wet and wet–dry transitions. The DOP fraction of TDP increased from 4% in dry<small>_(before)</small> baseflow to 64% at the end of the wet season. The DOP flux increment in stormflow was 20 folds compared to dry<small>_(before)</small> baseflow, while that of PO<small>₄</small>-P was 2 folds. DOP displayed the least spatial source heterogeneity with minimum anthropogenic pressure on inherent fluxes. DOP originated from overland and near-stream soil sources and was transported <em>via</em> surface runoff and soil water runoff, respectively. Across the wet season, the attrition of overland DOP sources and activation of near-stream soil DOP sources through strengthened hydrological connectivity governed the seasonal DOP trends. Surface and groundwater runoff pathways were important for PO<small>₄</small>-P delivery during stormflow; nonetheless, wastewater treatment plant (WWTP) effluent was the main PO<small>₄</small>-P source under both baseflow and stormflow regimes, followed by near-stream traditional agriculture lands. The interaction patterns of small dam systems with DP inputs through dry–wet periods were explained. The riverine PO<small>₄</small>-P fluxes were profoundly impacted by in-stream biogeochemical and physical processes and small dam systems, while riverine DOP fluxes were relatively less influenced.</p>","PeriodicalId":74,"journal":{"name":"Environmental Science: Processes & Impacts","volume":" 2","pages":" 373-389"},"PeriodicalIF":4.3,"publicationDate":"2025-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143044962","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}