Ione Loots, Jeffrey Colin Smithers, Thomas Rodding Kjeldsen
{"title":"Quantifying urban land cover imperviousness as input for flood simulation using machine learning: South African case study.","authors":"Ione Loots, Jeffrey Colin Smithers, Thomas Rodding Kjeldsen","doi":"10.2166/wst.2025.067","DOIUrl":"https://doi.org/10.2166/wst.2025.067","url":null,"abstract":"<p><p>The imperviousness of urban surfaces is an important parameter in simulating urban hydrological responses, but quantifying imperviousness can be challenging and time-consuming. In response, this study presents a new framework to efficiently estimate the imperviousness of urban surfaces, using satellite images with Red, Green and Blue bands and a land cover dataset with multiple built-up urban classes through remote sensing, machine learning and field verification. The methodology is adaptable to other regions with similar datasets. For a case study in Pretoria, South Africa, major differences in median total impervious area percentages (mTIA%) were identified when compared between land cover groups: residential areas had a lower imperviousness median (mTIA% = 38%) than commercial (mTIA% = 81%) and industrial (mTIA% = 89%) land cover. The mTIA% also varies between 17 and 61% for a range of different formally developed residential classes and between 14 and 43% for a range of different informally developed residential classes. These mTIA% are recommended for any urban area within the South African National Land Cover dataset. These values can be incorporated into hydraulic and hydrological models, which improve the efficiency of parameter estimation for modelling. The methodology successfully quantified temporal imperviousness changes in the study area.</p>","PeriodicalId":23653,"journal":{"name":"Water Science and Technology","volume":"91 10","pages":"1141-1156"},"PeriodicalIF":2.5,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144192308","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":"The refinement of the N<sub>2</sub>O emission factor originating from treated sewage water in rivers with different water qualities.","authors":"Hayato Kakishima, Ayaka Kagamu, Yoshitaka Ebie, Hiroshi Yamazaki","doi":"10.2166/wst.2025.055","DOIUrl":"https://doi.org/10.2166/wst.2025.055","url":null,"abstract":"<p><p>Treated sewage water flowing into rivers contains nitrogen (N) compounds, producing nitrous oxide (N<sub>2</sub>O) through nitrification and denitrification reactions. In Japan, environmental reference values have been set for water quality for various locations within waterways, and these are classified into six different categories based on the level of water quality. This study aimed to refine the N<sub>2</sub>O emission factor originating from treated sewage water by conducting year-round research on the production of dissolved N<sub>2</sub>O in rivers with varying concentrations of organic matter, N, and dissolved oxygen. There were differences in the N<sub>2</sub>O emission factor derived from the nitrification reaction of ammonium (NH<sub>4</sub>)-N due to the impact of N pollution load caused by the inflow of treated sewage water into rivers with different water qualities. The calculated N<sub>2</sub>O emission factor for rivers with relatively high water quality concentrations was 0.0028 kgN<sub>2</sub>O-N kgNH<sub>4</sub>-N<sup>-1</sup>, and the calculated average N<sub>2</sub>O emission factor originating from treated sewage water in rivers was 0.0026 kgN<sub>2</sub>O-N kgNH<sub>4</sub>-N<sup>-1</sup>.</p>","PeriodicalId":23653,"journal":{"name":"Water Science and Technology","volume":"91 9","pages":"1022-1031"},"PeriodicalIF":2.5,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144080776","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}
Carlos Montes, Sofia Guerrero, Maria Moreno, Laura Henao
{"title":"Tracing antibiotics in sewers: Concentrations, measurement techniques, and mathematical approaches.","authors":"Carlos Montes, Sofia Guerrero, Maria Moreno, Laura Henao","doi":"10.2166/wst.2025.053","DOIUrl":"https://doi.org/10.2166/wst.2025.053","url":null,"abstract":"<p><p>Antibiotic contamination in sewer networks has significant environmental and health concerns worldwide, primarily due to its role in promoting bacterial resistance. In this literature review, antibiotic concentrations reported in urban sewers and hospital effluents, techniques for antimicrobial compound detection and quantification, and current modeling strategies are analyzed and discussed based on 91 papers published between 2014 and 2024. One-hundred and nine antibiotic compounds were reported across 80 studies, with sulfonamides, fluoroquinolones, and macrolides being the most frequently detected classes, while amphenicols and aminocyclitols were the least monitored. Advanced analytical techniques such as liquid chromatography and mass spectrometry are the most common approaches used for antibiotic quantification. Modeling efforts remain limited, with kinetic models, Risk Quotient (RQ) assessments, and Wastewater-Based Epidemiology (WBE) representing the main approaches identified. This review compiles 992 reports into a comprehensive dataset intended to support future research, especially for global monitoring, the development of predictive models, and the formulation of regulatory frameworks for managing antibiotic pollution in sewer systems.</p>","PeriodicalId":23653,"journal":{"name":"Water Science and Technology","volume":"91 9","pages":"993-1009"},"PeriodicalIF":2.5,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144080778","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}
Pauline Ncube, Setumo Victor Motloung, Lehlohonolo Fortune Koao, Tshwafo Elias Motaung
{"title":"Remediation strategies of antiretroviral drugs in the aquatic environment: current trend and future perspectives.","authors":"Pauline Ncube, Setumo Victor Motloung, Lehlohonolo Fortune Koao, Tshwafo Elias Motaung","doi":"10.2166/wst.2025.064","DOIUrl":"https://doi.org/10.2166/wst.2025.064","url":null,"abstract":"<p><p>The presence of antiretroviral drugs (ARVs) in the aquatic environment highlights the inadequacy of traditional wastewater treatment plants in their remediation. Moreover, the fate and associated human and ecotoxicological impact of those compounds are not well established. In fact, research focusing on effective alternative treatment solutions still seems lacking. However, a growing interest in remediation techniques for pharmaceutical residues, including ARVs in wastewater, has been noticed recently. The main objective of this review is to share updated information and literature on the recent advances in wastewater treatment strategies to eliminate traces of ARVs from wastewater. Research gaps and possible ways forward for further research in the development of effective alternative treatments are well narrated in the current review. Furthermore, useful information can be derived from the highlighted biodegradation mechanisms to better understand the environmental fate of these compounds. An overview of different treatment methods is given, with particular emphasis on the removal efficiencies, reaction kinetics, degradation mechanisms, and process limitations. A summary of the environmental occurrence of ARVs is provided, as well as the status of the global HIV prevalence and antiretroviral therapy.</p>","PeriodicalId":23653,"journal":{"name":"Water Science and Technology","volume":"91 10","pages":"1077-1106"},"PeriodicalIF":2.5,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144192309","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}
German Dimitriv Jojoa-Unigarro, Simón González-Martínez, Yovany Cuetero-Martínez, Daniel de-Los-Cobos-Vasconcelos
{"title":"Fermentation of the organic fraction of municipal solid waste under different pH values and composition of microbial communities.","authors":"German Dimitriv Jojoa-Unigarro, Simón González-Martínez, Yovany Cuetero-Martínez, Daniel de-Los-Cobos-Vasconcelos","doi":"10.2166/wst.2025.059","DOIUrl":"https://doi.org/10.2166/wst.2025.059","url":null,"abstract":"<p><p>The organic fraction of municipal solid waste (OFMSW) must be stored for hours or days before being fed to the anaerobic digestion reactors. This storage leads to spontaneous lactic acid fermentation, and volatile fatty acids (VFAs) and ethanol are produced by naturally occurring microorganisms. This research deals with fermentation and hydrolysis by controlling the OFMSW storage (silage) conditions. Using only naturally occurring microorganisms as inoculum, OFMSW fermentation in a semi-continuous reactor at pH values of 4, 5, and 6 was performed. During 6 days, samples were collected and analyzed daily for VFAs, ethanol, and lactic acid. At pH 4, the main products were ethanol, lactic acid, and acetic acid; at pH 5, lactic acid predominated, decreasing after day 4; at pH 6, acetic acid formed rapidly and after day 1, the concentration remained constant. At pH 6, butyric acid reached the highest concentration of all VFAs. The microbial diversity increased with pH. Metataxonomic analysis supports the possibility that the fungus of the <i>Pichia</i> genus is responsible for ethanol production and that various bacteria are responsible for VFAs, lactic acid production, and acetogenesis. Acetogenesis was the main pathway for the decrease in lactic acid and ethanol over time.</p>","PeriodicalId":23653,"journal":{"name":"Water Science and Technology","volume":"91 9","pages":"1044-1057"},"PeriodicalIF":2.5,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144080770","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":"Quantifying sediment deposition in sewers through hydraulic performance analysis.","authors":"Zhi Yang, Biao Huang, David Z Zhu","doi":"10.2166/wst.2025.057","DOIUrl":"https://doi.org/10.2166/wst.2025.057","url":null,"abstract":"<p><p>This study investigates the effects of fixed sediment deposition on the hydraulic characteristics of sewer flow to support the diagnosis of sewer blockage. Sediment beds extending over the entire pipe (i.e., continuous deposition) and localized deposits were examined under different flow rates and outlet control conditions. Continuous deposition changes the cross-sectional area of the sewer pipe, while localized deposits act similarly to short bottom obstructions. The energy losses induced by a localized deposit at various locations were found to be nearly identical, particularly in cases with backwater effects. To illustrate the relationships between the flow rate, water level, and deposit characteristics, hydraulic performance curves can be developed. The inverse problem, which involves estimating parameters characterizing sediment deposition using observed flow rates and upstream and downstream water levels, can be solved by matching hydraulic performance curves with numerous scatter points from actual monitoring data to obtain the best fit. As there is a wide range of sediment deposition patterns that result in the same overall energy loss, the concept of equivalent sediment bed height is introduced to be applied in real-world scenarios.</p>","PeriodicalId":23653,"journal":{"name":"Water Science and Technology","volume":"91 9","pages":"1058-1076"},"PeriodicalIF":2.5,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144080772","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}
Ahmet Musluoğlu, Recep Kaan Dereli, Osman Atilla Arıkan, Serra Selin Övez
{"title":"Comprehensive experiences on the operation of a full-scale continuous dry anaerobic digestion plant treating mechanically sorted OFMSW.","authors":"Ahmet Musluoğlu, Recep Kaan Dereli, Osman Atilla Arıkan, Serra Selin Övez","doi":"10.2166/wst.2025.062","DOIUrl":"https://doi.org/10.2166/wst.2025.062","url":null,"abstract":"<p><p>Anaerobic digestion (AD) of the organic fraction of municipal solid waste (OFMSW) is a crucial waste management method for the diversion of organics from landfills to decrease greenhouse gas emissions while enabling energy recovery. A number of dry AD systems treating OFMSW have notably increased over the last two decades. In this study, mono-digestion of mechanically sorted OFMSW and co-digestion of OFMSW, chicken manure and WWTP sludge were evaluated using triplicate full-scale digesters. Results demonstrated that 5-6.6 m<sup>3</sup><sub>biogas</sub>/m<sup>3</sup><sub>reactor</sub>.day biogas could be produced at an organic loading rate (OLR) of 10.5-12 kg TVS/m<sup>3</sup>.day, with an HRT of 16-18 days. Beyond this threshold, further increases in OLR resulted in reduced gas production due to ammonia inhibition as a result of broiler chicken manure overload. Biogas yield decline started when the chicken manure content of the feed was increased to 10% (w/w) and accompanied with the VFA/TA ratio rising above 0.8. Process instability and a sharp drop in biogas productivity were observed when the feed contained more than 20% (w/w) chicken manure, where VFA/TA ratio exceeded 1.0. Results underline the importance of balancing different properties (e.g., degradability, carbon to nitrogen (C/N) ratio) of co-substrates to optimize the biogas yield and to ensure process stability.</p>","PeriodicalId":23653,"journal":{"name":"Water Science and Technology","volume":"91 10","pages":"1157-1171"},"PeriodicalIF":2.5,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144192306","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":"Novel approach for AI-based N<sub>2</sub>O emission reduction in biological wastewater treatment relying on genetic algorithms and neural networks.","authors":"Arne Freyschmidt, Stephan Köster","doi":"10.2166/wst.2025.060","DOIUrl":"https://doi.org/10.2166/wst.2025.060","url":null,"abstract":"<p><p>The potential of measurement-based control strategies for achieving lower N<sub>2</sub>O emissions in biological wastewater treatment is limited due to strong temporal variations in N<sub>2</sub>O emissions and a lack of measurement data regarding influencing parameters. To address this issue, a novel artificial intelligence (AI)-based process optimization method for minimizing N<sub>2</sub>O emissions was developed, relying on a genetic algorithm to automatically determine the control settings associated with minimum N<sub>2</sub>O emissions for an individual operating situation. The genetic algorithm employs a validated prediction model to evaluate the effect of individual control parameter sets on N<sub>2</sub>O emissions and other operating targets. For this purpose, neural networks were trained using data generated with a mechanistic model. This approach is beneficial in practical applications as prediction networks could be successfully trained even if only limited data is available. The developed method also includes a classification algorithm to check the reliability of the AI-suggested control strategy. Two modeling studies confirm that the practical application of the developed methodology holds the potential for a considerable reduction in emissions (43% or 1,588 t CO<sub>2</sub>e/a) while still achieving the required effluent quality. Operational settings are identified in less than 2 minutes so that the approach can be applied on a large scale.</p>","PeriodicalId":23653,"journal":{"name":"Water Science and Technology","volume":"91 10","pages":"1172-1184"},"PeriodicalIF":2.5,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144192307","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":"Recovery of coagulants via acid treatment in potabilization sludges and their reuse in raw and urban wastewaters.","authors":"Cristian Danilo Vargas-Velez, Iván Andrés Sánchez Ortiz, Tsunao Masumoto","doi":"10.2166/wst.2025.058","DOIUrl":"https://doi.org/10.2166/wst.2025.058","url":null,"abstract":"<p><p>Conventional water treatment plants have used aluminum-based coagulant solutions to remove colloidal substances and other suspended particles from raw water. During this process, a byproduct known as water treatment sludge (WTS) is generated that is typically discharged without prior treatment, causing serious environmental problems for surface waters and nearby ecosystems. Studies have been conducted to evaluate its potential reuse in various processes such as agriculture, construction material manufacturing, pollutant absorption, and its reuse as a coagulant. This study evaluated the recovery of aluminum via acid treatment in WTS from a drinking water treatment plant (DWTP) that supplies water for a population of 413,484 inhabitants, using different pH levels and mixing speeds. The efficiency of the recovered coagulants was evaluated for the removal of color and turbidity in raw and wastewater. The main results showed a maximum aluminum recovery at a pH of 1.5 with values up to 810.5 mg Al/L, with pH being the most influential factor in the process. The removal of color and turbidity of 95.84 and 97.06% were achieved in wastewater and 69.78 and 69.73% in raw water, respectively. The recovered coagulant could be used in DWTPs and in chemically enhanced primary treatment for sewage treatment.</p>","PeriodicalId":23653,"journal":{"name":"Water Science and Technology","volume":"91 9","pages":"1010-1021"},"PeriodicalIF":2.5,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144080775","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":"Comparative study of various reference evapotranspiration models under different agroclimatic zones.","authors":"Diksha Chaudhary, Abhishek Sharma, Vijay Shankar","doi":"10.2166/wst.2025.065","DOIUrl":"https://doi.org/10.2166/wst.2025.065","url":null,"abstract":"<p><p>Reference evapotranspiration (ET<sub>o</sub>) study is important for climatically diverse Himachal Pradesh to ensure sustainable water resource management. The present study aims to establish the best alternative ET<sub>o</sub> method among the combination-, radiation-, and temperature-based methods. The study area consists of four agroclimatic zones (zone I: subtropical, zone II: humid, zone III: wet temperate, zone IV: dry temperate) of Himachal Pradesh, state of India. The statistical performance indicators, i.e., root mean square error (RMSE), coefficient of determination (<i>R</i><sup>2</sup>), percentage error (PE), and scatter index (SI), were used to evaluate model performance in each agroclimatic zone over the period of 2012-2021. In combination methods, corrected Penman (CPEN), and modified Penman (MPEN) performed well; however, the results of CPEN were found to be significantly closer to 56PM for all agroclimatic zones. Among the radiation methods, the Priestly-Taylor (P-T) model was found to be a better predictor than the other three methods, i.e., 24-radiation (24RAD), Turc (T-C), and Makkink (MAK) for agroclimatic zone I and zone II. For zones III and IV, the T-C method outperformed all other radiation methods, followed by MAK. The results of the study established that H-S (RMSE = 0.87, <i>R</i><sup>2</sup> = 0.98, PE = 2.63, SI = 0.13) as a temperature method, outperformed other methods in the study area, followed by P-T and T-C methods.</p>","PeriodicalId":23653,"journal":{"name":"Water Science and Technology","volume":"91 10","pages":"1107-1127"},"PeriodicalIF":2.5,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144192305","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}