{"title":"Enhanced biomethane production via hydrodynamic cavitation pretreatment and co-digestion of brown and DAF sludge.","authors":"Md Saiful Islam, Vivek Vinayak Ranade","doi":"10.2166/wst.2025.056","DOIUrl":"https://doi.org/10.2166/wst.2025.056","url":null,"abstract":"<p><p>This study introduces a co-digestion and vortex-based hydrodynamic cavitation (HC) pretreatment of brown and dissolved air flotation (DAF) sludge derived from dairy processing waste streams to enhance biomethane potential (BMP). Co-digestion experiments were carried out for varying ratios of brown-to-DAF sludge (1:1, 2%; 3:1, 4%). The BMP tests, conducted at 39 °C using a 15-reactor system with a 400 mL reaction volume and overhead stirrers, demonstrated that HC treatment elevated soluble chemical oxygen demand (sCOD) of brown and DAF sludges by over 34% after 80 passes through HC device. Combining DAF with brown sludge improved methane yields and reduced the time to reach peak BMP. Loading 2% volatile solids (VS) with a 1:1 ratio resulted in methane production exceeding 90% of theoretical BMP, surpassing individual brown and DAF sludge BMPs (73 and 84%, respectively). Maximum VS removal surpassed 85%, achieving a peak methane yield of over 717 mL/g-VS. These findings offer insights into addressing effluent treatment challenges and highlight the potential of co-digestion for enhanced waste valorisation.</p>","PeriodicalId":23653,"journal":{"name":"Water Science and Technology","volume":"91 9","pages":"1032-1043"},"PeriodicalIF":2.5,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144080769","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Beatriz Cruz Amback, A P Veról, M M Sousa, L E S Saraiva, M G Miguez
{"title":"A framework for urban planning structured by sustainable urban drainage: the proposal of a priority matrix for site selection.","authors":"Beatriz Cruz Amback, A P Veról, M M Sousa, L E S Saraiva, M G Miguez","doi":"10.2166/wst.2025.061","DOIUrl":"https://doi.org/10.2166/wst.2025.061","url":null,"abstract":"<p><p>Urbanization transforms landscapes, increasing urban flooding risk due to changes in the water cycle. Urban planning should incorporate blue and green infrastructure (BGI) to integrate flood mitigation strategies within the landscape under a multifunctional approach. This work aims to develop, apply, and evaluate supportive tools to guide urban planning actions focused on effective urban drainage choices in a sustainable and resilient manner. An original multicriteria tool, named the Priority Matrix, combines gravity, urgency, and tendency assessments to define focal areas for drainage interventions. The index is applied to a selected watershed, leading to a critical analysis that generates guidelines for urban projects and identifies focal points for urban design. A multifunctional urban design intervention combining grey, blue, and green infrastructure was proposed for the site to achieve flood mitigation. The project was evaluated using a hydrological-hydrodynamic simulation tool, confirming the index's purpose and efficiency in selecting critical sites and informing discussions about local challenges. The evaluation demonstrated success in flood mitigation, illustrating the potential for creating multifunctional landscapes that incorporate social and ecological functions into effective urban drainage projects.</p>","PeriodicalId":23653,"journal":{"name":"Water Science and Technology","volume":"91 10","pages":"1185-1202"},"PeriodicalIF":2.5,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144192304","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Bongseok Jeong, Hyunjoo Shin, Jihoon Shin, YoonKyung Cha
{"title":"The analysis of spatiotemporal effects of environmental factors on harmful algal blooms in a bloom-prone river using partial least squares structural equation modeling.","authors":"Bongseok Jeong, Hyunjoo Shin, Jihoon Shin, YoonKyung Cha","doi":"10.2166/wst.2025.066","DOIUrl":"https://doi.org/10.2166/wst.2025.066","url":null,"abstract":"<p><p>Since rivers are adversely affected by harmful algal blooms (HABs), it is necessary to develop countermeasures through analyzing the relationship between environmental variables and HABs. This study focused on analyzing the connections between HABs and environmental variables in the middle reaches of the Nakdong River in South Korea. Partial least squares structural equation modeling (PLS-SEM) was used to identify those relationships. The study developed three different PLS-SEM models to investigate various aspects, including lagged effects of environmental factors, influences from upstream and tributaries, and interactions between genera of HABs. The results of the study revealed that the magnitude of HABs had the strongest relationships with nutrient concentrations, particularly 1 week prior to HABs measurement. Additionally, the magnitude of HABs showed stronger relationships with upstream nutrient concentrations compared with tributaries' nutrient concentrations. Furthermore, the dominant genus of HABs in the study area, <i>Microcystis</i>, showed significant relationships with temperature and nutrient concentrations. However, the study did not find significant relationships between <i>Microcystis</i> and other harmful cyanobacteria genera. The methodological framework provides valuable insight into the management of HABs. It allows for the analysis of multiple aspects of the relationships between environmental factors and HABs, which is crucial for effective water resource management.</p>","PeriodicalId":23653,"journal":{"name":"Water Science and Technology","volume":"91 10","pages":"1128-1140"},"PeriodicalIF":2.5,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144192310","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Jumanne Mayige Shimba, Oscar Ezekiel Njau, Juma Selemani, Karoli Nicholaus Njau
{"title":"Brine recovery from reverse osmosis effluents using an automatic temperature control system: salt crystallization.","authors":"Jumanne Mayige Shimba, Oscar Ezekiel Njau, Juma Selemani, Karoli Nicholaus Njau","doi":"10.2166/wst.2025.047","DOIUrl":"https://doi.org/10.2166/wst.2025.047","url":null,"abstract":"<p><p>The improper brine effluent disposal from the reverse osmosis (RO) process of the industry and mining sites poses various environmental problems including impaired soil ability to produce crops, difficulties for breeding and migrating birds. Various treatment methods reported to provide a short-term solution in which separation of the mixed salt byproducts remains a great challenge. The present study aimed at assessing the performance of locally available automatic temperature control (ATC) system to recover brine from RO effluents through salt crystallization. Laboratory trials via batch experiment containing individual and mixed samples of NaCl·2H<sub>2</sub>O, Na<sub>2</sub>SO<sub>4</sub>·10H<sub>2</sub>O, and Na<sub>2</sub>CO<sub>3</sub>·10H<sub>2</sub>O were conducted to evaluate the influence of freezing temperature, concentration, and contact time. The maximum recovery efficiencies of 85.3% (NaCl·2H<sub>2</sub>O), 93.3% (Na<sub>2</sub>SO<sub>4</sub>·10H<sub>2</sub>O), and 32.0% (Na<sub>2</sub>CO<sub>3</sub>·10H<sub>2</sub>O) of the individual samples were achieved at 72 h (-26 °C), 96 h (-10 °C), and 2 h (-2 °C), respectively. For mixed samples at -10 °C and 3 h in 50 mL, 29.37 g (65.27%) were recovered with ionic constituents such as Na<sup>+</sup> (34.1%), Cl<sup>-</sup> (1.6%), SO<sub>4</sub><sup>2-</sup> (11.3%), CO<sub>3</sub><sup>2-</sup> (32.4%), and impurities (20.57%). The findings of this study suggested that ATC could be used as an alternative technology for brine recovery from RO process of industry and mining operation sites.</p>","PeriodicalId":23653,"journal":{"name":"Water Science and Technology","volume":"91 8","pages":"946-959"},"PeriodicalIF":2.5,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144048970","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"Sewage treatment plants as a potential source of microplastics in the environment: A preliminary study in Central India.","authors":"Surya Singh, Bablu Alawa, Sankar Chakma, Madhanraj Kalyanasundaram, Vishal Diwan","doi":"10.2166/wst.2025.041","DOIUrl":"https://doi.org/10.2166/wst.2025.041","url":null,"abstract":"<p><p>The presence of microplastics in various environmental matrices is a reality. Besides, sewage treatment plants (STPs) play a crucial role in further adding to the microplastic pool of the environment, especially in water and soil resources. As conventional STPs are not primarily meant to remove microplastics, treated effluent and sludge contain a significant amount of microplastic items which are ultimately discharged into the surface water/soil. The present study investigated the role of selected STPs of Central India in contributing microplastics to the environment. Inlet, outlet, and sludge samples were collected from seven STPs and analyzed for the presence of microplastics. Microplastics were found in all samples with higher amounts in the inlet samples (3-35.5 items/L) compared to the outlet samples (2-13.5 items/L). Nevertheless, sludge samples showed the highest amount of microplastics (16-389 items/kg) for all the STPs under study. Size, shape, color, and chemical composition of microplastics was varied with considerable presence of polyethylene, polypropylene, polyethylene-terephthalate, polyvinylchloride, polystyrene, polyamide, polyacrylamide, polyester, and polyurethane. Discharge of these microplastic items in the surface water and terrestrial ecosystems may result in serious consequences for ecology and human health. Therefore, advanced technological development for effective microplastics' removal in STPs is inevitable.</p>","PeriodicalId":23653,"journal":{"name":"Water Science and Technology","volume":"91 7","pages":"783-796"},"PeriodicalIF":2.5,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144052428","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Salini Pottekkatt, Jennipher George, Riya Zakkariya, Christo P N, Gouri Nair, Madhu Gopal, Renu Pawels
{"title":"Integrated biological and UV-Fenton processes for the treatment of automobile service station wastewater.","authors":"Salini Pottekkatt, Jennipher George, Riya Zakkariya, Christo P N, Gouri Nair, Madhu Gopal, Renu Pawels","doi":"10.2166/wst.2025.054","DOIUrl":"https://doi.org/10.2166/wst.2025.054","url":null,"abstract":"<p><p>Automobile service stations are a significant contributor to environmental issues due to the release of harmful wastewater containing various pollutants like oils, grease, detergents, and organic and inorganic substances. Our study focused on treating this wastewater through both biological and UV-Fenton methods to target the removal of chemical oxygen demand (COD), turbidity, and oil and grease for potential reuse. In the biological approach, we isolated diverse microorganisms from the wastewater, and the predominant microorganism identified through 16S rRNA sequencing was <i>Pseudomonas aeruginosa</i>. Key parameters, including pH (6.2) and incubation time (45.6 h), were optimized using response surface methodology (RSM) to enhance pollutant degradation. The microorganisms were immobilized on biofilm carriers, achieving significant reductions: 83% COD, 93% turbidity, and 67% oil and grease. For the second method, we employed a UV-Fenton-based advanced oxidation process, optimizing Fe<sup>2+</sup> dosage (42.4 mg/L) and H<sub>2</sub>O<sub>2</sub> concentration (412.1 mg/L). This process demonstrated substantial reductions: 89% COD, 95% turbidity, and 72% oil and grease. Combining both biological and UV-Fenton treatments in series yielded even better outcomes with reductions of 89% COD, 96% turbidity, and 78% oil and grease. This integrated approach proved highly effective in meeting wastewater quality standards, demonstrating significant pollutant reduction within acceptable limits.</p>","PeriodicalId":23653,"journal":{"name":"Water Science and Technology","volume":"91 8","pages":"977-992"},"PeriodicalIF":2.5,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144039057","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Michal Šereš, Tereza Černá, Tereza Hnátková, Miloš Rozkošný, Alena Grasserová, Jaroslav Semerád, Kateřina Němcová, Tomáš Cajthaml
{"title":"Environmental aspects of wastewater recycling from the point of view of emergent pollutant removal.","authors":"Michal Šereš, Tereza Černá, Tereza Hnátková, Miloš Rozkošný, Alena Grasserová, Jaroslav Semerád, Kateřina Němcová, Tomáš Cajthaml","doi":"10.2166/wst.2025.042","DOIUrl":"https://doi.org/10.2166/wst.2025.042","url":null,"abstract":"<p><p>This study evaluates the removal efficiency of 15 estrogenic endocrine-disrupting compounds in two operational constructed wetlands with different designs: a hybrid system (constructed wetland A) and a horizontal system (constructed wetland B). The assessment involved analyzing composite water samples obtained from passive samplers through liquid chromatography-mass spectrometry coupled with yeast assays. Additionally, grab samples of sludge and sediment were examined to determine the endocrine-disrupting compound's adsorption efficacy. The application of the full logistic model enabled the discernment and ranking of the chemicals contributing to mixture toxicity. The findings revealed constructed wetland A's superior efficacy in the removal of individual endocrine-disrupting compounds (with an average efficiency of 94%) compared to constructed wetland B (60%). Furthermore, constructed wetland A displayed a higher estimated estrogenic activity removal efficiency (83%) relative to constructed wetland B (52%). Estrogenic activity was adequately accounted for (58-120%) in half of the analyzed samples, highlighting estrone as the primary estrogenic agent. The investigation underscores constructed wetlands' effectiveness in purging endocrine-disrupting compounds, suggesting that their integration as secondary or tertiary treatment systems for such pollutants removal merits further exploration.</p>","PeriodicalId":23653,"journal":{"name":"Water Science and Technology","volume":"91 7","pages":"876-892"},"PeriodicalIF":2.5,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144000126","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Manting Shang, Jiaao Huang, Peigui Liu, Jingjing Gao, Jiaxuan Li
{"title":"Coupled exponential smoothing and gray model for water quality prediction in the Guo River, China.","authors":"Manting Shang, Jiaao Huang, Peigui Liu, Jingjing Gao, Jiaxuan Li","doi":"10.2166/wst.2025.051","DOIUrl":"https://doi.org/10.2166/wst.2025.051","url":null,"abstract":"<p><p>To address the issue of poor prediction accuracy and performance caused by the influence of the original data sequence on the first-order single-variable gray model (GM(1,1)), this study proposes an exponential smoothing gray model (ESGM(1,1)). Taking the Anliu Station situated at the border between Henan and Anhui provinces as an example, ammonia nitrogen and the permanganate index were selected for water quality prediction using the GM(1,1) and ESGM(1,1) models from 2010 to 2021. The fitting accuracy of these models is evaluated by comparing the computed values with the actual monitored water quality index values. The results reveal that the average relative percentage error in the simulation period decreased by 3.01% compared with GM(1,1) and further decreased by 27.41% during the verification period. The mean square error ratio <i>C</i> of GM(1,1) was 0.79, which failed the fitting accuracy test. The <i>C</i> value of ESGM(1,1) was 0.59, which successfully passed the test. The predicted results were consistent with the monitoring data from 2010 to 2021. It is concluded that ESGM(1,1) shows superior accuracy for short-term water quality prediction. This model mitigates the impact of the initial sequence on prediction accuracy and can be utilized for local water pollution control and environmental protection.</p>","PeriodicalId":23653,"journal":{"name":"Water Science and Technology","volume":"91 8","pages":"960-976"},"PeriodicalIF":2.5,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144034908","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"Cultivation of anammox bacteria from a tropical lake in Indonesia using a novel filter bioreactor to enhance nitrogen removal efficiency.","authors":"Zulkarnaini Zulkarnaini, Puti Sri Komala, Randi Permana Putra, Muhammad Ali, Norihisa Matsuura, Kazuyoshi Koike, Jinsong Wang, Panji Cahya Mawarda, Ryoko Yamamoto-Ikemoto","doi":"10.2166/wst.2025.050","DOIUrl":"https://doi.org/10.2166/wst.2025.050","url":null,"abstract":"<p><p>This study presents a novel strategy for cultivating anammox bacteria from tropical environments using a filter bioreactor (FtBR). Two bioreactors were inoculated with sediment sludge from an Indonesian lake and operated at different temperatures: tropical ambient (22-28 °C) in Reactor 1 and 35 °C in Reactor 2. After 106 days, Reactor 1 developed a red carmine anammox biofilm, while Reactor 2 remained similar to its initial state. Reactor 1 achieved a higher and more stable nitrogen removal rate (0.27 kg-N/m<sup>3</sup>·d) compared with Reactor 2 (0.21 kg-N/m<sup>3</sup>·d), indicating a 28.6% greater efficiency. The operational temperature significantly influenced the diversity and abundance of anammox bacteria. <i>Candidatus Brocadia caroliensis</i> (6.20%) was detected in Reactor 1, whereas <i>Candidatus Anammoxoglobus propionicus</i> (7.64%) and <i>Candidatus Brocadia sinica</i> (1.77%) were found only in Reactor 2. Additionally, <i>Candidatus Brocadia fulgida</i> was more abundant in Reactor 1 (20.04%) than in Reactor 2 (6.84%). These findings demonstrate that temperature plays a crucial role in starting the anammox process in FtBRs with a resident inoculum from tropical environments, significantly affecting bacterial growth and nitrogen removal efficiency.</p>","PeriodicalId":23653,"journal":{"name":"Water Science and Technology","volume":"91 7","pages":"811-826"},"PeriodicalIF":2.5,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144012571","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Wei Liu, Jun Chen, Haotian Li, Shuguang Zhu, Zheng Duan
{"title":"Assessing carbon emission impacts of sponge city development: insights from runoff reduction analysis.","authors":"Wei Liu, Jun Chen, Haotian Li, Shuguang Zhu, Zheng Duan","doi":"10.2166/wst.2025.046","DOIUrl":"https://doi.org/10.2166/wst.2025.046","url":null,"abstract":"<p><p>This study aimed to quantify the impact of sponge city facilities on both runoff reduction and carbon emission mitigation, providing valuable insights for sustainable urban development. Using the Storm Water Management Model (SWMM) 5.2 in conjunction with carbon emission factor calculations, we comparatively evaluated the annual runoff reduction and carbon emission abatement potential of traditional drainage systems versus those incorporating sponge city facilities. Our results showed that the implementation of sponge city facilities resulted in a substantial decrease in runoff volume (100,840 m<sup>3</sup>), and a corresponding reduction in carbon emissions (7,089.85 kg CO<sub>2</sub> eq) compared to the pre-renovation conditions. Additionally, this work assessed five sponge city facilities: green roofs, permeable pavements, sunken green spaces, rain gardens, and overflow storage ponds. Among these, overflow storage ponds demonstrated the highest efficiency in both runoff reduction (35,879 m<sup>3</sup>) and carbon emission mitigation (2,522.57 kg CO<sub>2</sub> eq). Rain gardens showed the second-best performance, while sunken green spaces had the least impact. Our study provides a novel technical framework for quantifying and evaluating carbon emissions in urban drainage systems. Our findings offer reliable data support for urban planners and policymakers, contributing to evidence-based decision-making in the design and implementation of sponge city projects.</p>","PeriodicalId":23653,"journal":{"name":"Water Science and Technology","volume":"91 8","pages":"923-945"},"PeriodicalIF":2.5,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144042569","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}