Applied Water Science最新文献

{"title":"Evaluating the contamination susceptibility of groundwater resources through anthropogenic activities in Islamabad, Pakistan: a GIS-based DRASTIC approach","authors":"Fayaz Ullah Shinwari,&nbsp;Mumtaz Ali Khan,&nbsp;Syed Mamoon Siyar,&nbsp;Urooj Liaquat,&nbsp;George Kontakiotis,&nbsp;Mohamed Zhran,&nbsp;Muhammad Shahab,&nbsp;Fahad Alshehri","doi":"10.1007/s13201-025-02374-9","DOIUrl":"10.1007/s13201-025-02374-9","url":null,"abstract":"<div><p>The problem of access to clean water has been highlighted by the United Nation’s Sustainable Development Goals, and in areas such as Islamabad, Pakistan, water pollution is more of an immediate concern. The impact of excessive use of fertilizers coupled with improper waste management has harmed aquifers. This necessitates the need for tools to map out regions of concern and assist with clean-up strategies. This paper uses an amalgamation of the DRASTIC model and GIS capabilities to evaluate the contamination threat to aquifers in Islamabad. The model involves seven components: depth to water, recharge, aquifer media, soil media, topography, impact of the vadose zone, and hydraulic conductivity, and formulates an index of susceptibility within the range of 275–900. The areas were classified into five categories according to their level of susceptibility: very low (275–400; 22 km², 2%), low (400–525; 306 km², 28%), moderate (525–650; 500 km², 47%), high (650–775; 221 km², 21%), and very high (775–900; 26 km², 2%). Twenty-eight of the samples had nitrate concentrations ranging from − 0.72 ppm to 2.8 ppm which helped calibrate the model and did not show a high correlation with the DRASTIC index. This suggests that the contamination was limited and did not originate from widespread sources. The results highlight the importance of focusing measures on high-risk areas, such as Rawal Lake and the National Agricultural Research Center, where risks of contamination are severe. The baseline that the present study has developed is useful in terms of safe groundwater extraction and also offers a workable methodology for urban groundwater management practices in the world. Its usefulness is enhancing policies aimed at protecting clean water resources and reducing the risk of environmental degradation in sensitive areas worldwide.</p></div>","PeriodicalId":8374,"journal":{"name":"Applied Water Science","volume":"15 4","pages":""},"PeriodicalIF":5.7,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s13201-025-02374-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143645468","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":"Urban flood hazard assessment using FLA-optimized boost algorithms in Ankara, Türkiye","authors":"Enes Gul","doi":"10.1007/s13201-025-02424-2","DOIUrl":"10.1007/s13201-025-02424-2","url":null,"abstract":"<div><p>This study presents a comprehensive analysis of flood hazard mapping in Ankara, the capital of Türkiye, highlighting the critical vulnerability of this major urban center to climate-related disasters. By applying advanced boosting algorithms—specifically, XGBoost, GradientBoost, and CatBoost—along with hyperparameter optimization through the Fick’s law algorithm (FLA), this research introduces an innovative methodology aimed at improving the reliability and accuracy of flood hazard assessments in Ankara’s urban landscape. The analysis utilizes an extensive dataset that integrates topographic, meteorological, hydrological, and anthropogenic variables to provide critical insights into the dynamics of urban flooding with a focus on Ankara’s vulnerability. This approach is novel in that it incorporates FLA for hyperparameter optimization, marking a significant advancement in flood hazard modeling and achieving higher model accuracy and generalizability. Notably, among the various determinants of flood hazard identified, elevation emerges as the most influential factor affecting flood risk in Ankara. This finding underscores the complex relationship between urban geography and flood hazards, and highlights the need for targeted urban planning and infrastructure development strategies to effectively mitigate flood risk. The implications of this research extend beyond the local setting, contributing valuable insights to the global discourse on climate change adaptation and urban resilience. By combining cutting-edge machine learning techniques with in-depth geographic analysis, this study offers a scalable and innovative model for flood hazard assessment and management, providing a critical tool for cities around the world facing similar challenges.</p></div>","PeriodicalId":8374,"journal":{"name":"Applied Water Science","volume":"15 4","pages":""},"PeriodicalIF":5.7,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s13201-025-02424-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143645467","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":"Short-term salinity prediction for coastal areas of the Vietnamese Mekong Delta using various machine learning algorithms: a case study in Soc Trang Province","authors":"Le Thi Thanh Dang,&nbsp;Hiroshi Ishidaira,&nbsp;Ky Phung Nguyen,&nbsp;Kazuyoshi Souma,&nbsp;Jun Magome","doi":"10.1007/s13201-025-02419-z","DOIUrl":"10.1007/s13201-025-02419-z","url":null,"abstract":"<div><p>Saltwater intrusion has significant and diverse impacts on agriculture, freshwater resources, and the well-being of coastal communities. To effectively address this issue, precise models for predicting saltwater intrusion must be developed, as well as timely information for reaction planning. In this study, a spectrum of machine learning (ML) methodologies, specifically Random Forest Regression (RFR), Support Vector Regression (SVR), Long Short-Term Memory (LSTM), Artificial Neural Network (ANN), Extreme Gradient Boosting (XGBoost), and Ridge Regression (RR), was systematically employed to predict salinity levels within the coastal environs of the Mekong Delta, Vietnam. The input dataset comprised hourly salinity measurements from Tran De, Long Phu, Dai Ngai, and Soc Trang stations and hourly water-level data from Tran De station and hourly discharge data from the Can Tho hydrological station. The dataset was partitioned into two distinct sets for the purpose of model development and evaluation, employing a division ratio of 75% for training (constituting 8469 observations) and 25% for testing (comprising 2822 observations). The results indicate that ML models are suitable for short-term salinity prediction, with a forecasting time of up to 16 h in this area. These research findings highlight the potential of machine learning in addressing saltwater intrusion and provide valuable insights for developing appropriate response policies. By leveraging the strengths of these models and considering the optimal forecasting time, policymakers can make informed decisions and implement effective measures to mitigate the impacts of saltwater intrusion in the Mekong Delta.</p></div>","PeriodicalId":8374,"journal":{"name":"Applied Water Science","volume":"15 4","pages":""},"PeriodicalIF":5.7,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s13201-025-02419-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143645466","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":"Identifying the factors controlling surface water and groundwater chemical characteristics and suitability in the East Nile Delta Region, Egypt","authors":"Alaa Ahmed,&nbsp;Dalal Alshamsi,&nbsp;Hasan Arman,&nbsp;Abdulaziz M. Abdulaziz","doi":"10.1007/s13201-025-02412-6","DOIUrl":"10.1007/s13201-025-02412-6","url":null,"abstract":"<div><p>In the East Nile Delta Region, Egypt, water scarcity is a major concern, as the shallow Quaternary aquifer has been observed to experience a persistent decline in groundwater levels alongside a deterioration in groundwater quality. The present study was carried out to identify the processes that control water quality mainly in relation to salinity sources and the suitability for drinking and irrigation purposes in the study area. To achieve this aim, 19 surface water and 110 groundwater samples were analyzed for physical parameters (TDS, pH, temperature, and EC), major ions (Na, Ca, K, Mg, Cl, SO₄, and HCO₃) along with spatial and multivariate statistical analysis. The geospatial distribution of the total dissolved solids (TDS) and majority of the major chemical ions show an evident increase toward the north and northeast parts of the study area. Graphical methods using Gibbs plot and Piper diagram showed that water chemistry was mainly affected by weathering and water rock interaction while the geochemical evolution results revealed the dissolution and precipitation of carbonates and silicates, ion exchange processes, dissolved evaporite minerals, and anthropogenic activities. Still, the geochemical processes of surface water and groundwater were different. Additionally, the chemical data were analyzed using factor analysis to identify the most important factors influencing the variation in water quality. In the present study, three main factors explaining 92.47 and 80.95% of the total variance were identified as responsible for the surface water and groundwater chemistry variations from which the first factor (53.79% and 54.08% for surface water and groundwater, respectively), represented a natural weathering and salt accumulations, the second factor (28.60 and 13.52% for both waters) constituted agricultural activities, and the third factor (10.9 and 13.89% for the two types of water) is a contribution from dissolution processes. The results also indicated that 66.3% of the samples fell into the excellent category, 16.4% were considered good, 11.8% were doubtful, and 5.5% were unsuitable. In terms of surface water, 89.5% were classified as excellent, with 10.5% rated as good for irrigation, because of their high sodium levels and salinity. The study results provide a basis for the sustainable utilization of regional water resources.</p></div>","PeriodicalId":8374,"journal":{"name":"Applied Water Science","volume":"15 4","pages":""},"PeriodicalIF":5.7,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s13201-025-02412-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143612091","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":"A comprehensive evaluation framework for green ecological urban underground space using factor analysis and AHP","authors":"Chao Jiang,&nbsp;Ting Jiang,&nbsp;Bin Zhu,&nbsp;Wen LIU,&nbsp;Abbas Abd Ali Abbood,&nbsp;M. Mehdi Shafieezadeh","doi":"10.1007/s13201-025-02421-5","DOIUrl":"10.1007/s13201-025-02421-5","url":null,"abstract":"<div><p>Urban underground space (UUS) provides innovative solutions to urban challenges such as overpopulation, resource scarcity, and environmental issues. However, UUS's lack of comprehensive evaluation standards hinders its sustainable development. This study systematically introduces a novel framework for evaluating green ecological UUS, integrating methodologies such as factor analysis, the analytic hierarchy process (AHP), and the Delphi method. The framework assesses UUS projects across their lifecycle, focusing on energy efficiency, resource conservation, and environmental protection. Validation through real-world projects, including Chengdu's Tianfu Square and East Railway Station, demonstrated its practical utility, classifying both projects as two-star ecological grades. Real-world projects, such as Chengdu's Tianfu Square and East Railway Station, validated the framework, classifying them into two-star ecological grades based on the proposed standards. This research provides a valuable theoretical and practical tool for establishing a robust evaluation standard for sustainable UUS development, contributing to global urban sustainability efforts.</p></div>","PeriodicalId":8374,"journal":{"name":"Applied Water Science","volume":"15 4","pages":""},"PeriodicalIF":5.7,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s13201-025-02421-5.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143612141","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":"Investigating adsorption of aqueous heavy metals through isotherms and kinetics with Zn-Co-Fe/LDH for remarkable removal efficiency","authors":"Saher A. Aita,&nbsp;Rehab Mahmoud,&nbsp;Sarah. H. M. Hafez,&nbsp;Amal Zaher","doi":"10.1007/s13201-025-02390-9","DOIUrl":"10.1007/s13201-025-02390-9","url":null,"abstract":"<div><p>Heavy metals can be extracted from aqueous solutions by using the Zn-Co-Fe/LDH adsorbent (2:2:1 M), which was made by coprecipitation. Many of analytical methods, inclusive the scanning electron microscope (SEM), X-ray diffraction (XRD), and infrared spectroscopy (FTIR), were applied to evaluate the produced adsorbent. The impact of adsorption factors consisting adsorbent dosage, time, initially adsorbate concentration, and solution pH was estimated. The Zn-Co-Fe/LDH material’s crystal structure is verified by X-ray diffraction investigation of the sample. As³⁺, Pb²⁺, and Hg²⁺ ions were successfully removed from the watery solution using the Zn-Co-Fe/LDH adsorbent. At pH range from 3 to 9, the maximal removal of As³⁺ ions reached 74%, whereas that of Pb²⁺ and Hg²⁺ ions reached 100%. The maximum adsorption capacity of LDH was determined by utilizing five model isotherms, the best model was Langmuir–Freundlich model and the maximum adsorption capacity was 529.63 mg/g, 2741.5 mg/g, and 1852.9 mg/g, respectively. The temperature experiments were conducted at 25, 35, 45, and 55 °C to investigate the thermodynamic parameters <span>(Delta)</span> <i>H</i>^o, <span>(Delta)</span> <i>S</i>^o, and <span>(Delta)</span> <i>G</i>^o. The calculated values show exothermic and non-spontaneous adsorption processes. The results revealed that heavy metals removal mechanisms involved physical and chemical adsorption. The reuse of adsorbent study was performed and discussed. In regard to this study, Zn-Co-Fe/LDH is a material that shows promise for treating industrial wastewater by effectively removing heavy metals from aqueous solutions.</p></div>","PeriodicalId":8374,"journal":{"name":"Applied Water Science","volume":"15 4","pages":""},"PeriodicalIF":5.7,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s13201-025-02390-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143612147","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":"Numerical modeling of optimal location of drainage and cutoff wall under small concrete dams","authors":"Abbas Parsaie,&nbsp;Fatemeh Avazpour,&nbsp;Ehsan Afaridegan","doi":"10.1007/s13201-025-02422-4","DOIUrl":"10.1007/s13201-025-02422-4","url":null,"abstract":"<div><p>This study presents a rigorous investigation into determining the optimal placement of a drainage well and cutoff wall to effectively mitigate the uplift force and seepage discharge in small concrete dams. A sophisticated numerical model based on the two-dimensional Laplace equation was developed for this purpose. The Laplace equation was discretized using the finite difference method with a second-order central schema, and the resulting system of equations was efficiently solved using the Gauss–Seidel method with an over-relaxation factor of 1.95. The Neumann boundary conditions were applied to the dam body and cutoff wall, while Dirichlet boundary conditions were imposed on the drainage well, as well as the upstream and downstream sections of the dam. The results exhibited an excellent agreement between the numerical simulations and the observed data, with a mean absolute percentage error of 3.54%. The findings from the numerical simulations revealed that the optimal location for the drainage well is at a distance of 0.2<i>L</i> from the upstream face of the dam, where <i>L</i> represents the dam length. This location resulted in a notable reduction of approximately 38% in the uplift force. Additionally, utilizing a cutoff wall at the upstream portion of the dam led to a reduction of about 15% in the uplift force. Remarkably, when both a cutoff wall and a drainage well were employed at their respective optimal locations, the uplift force decreased by an impressive 53%.</p></div>","PeriodicalId":8374,"journal":{"name":"Applied Water Science","volume":"15 4","pages":""},"PeriodicalIF":5.7,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s13201-025-02422-4.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143612142","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":"Prediction of cavitation damage using SVM model based on air–water two-phase flow over dam spillway","authors":"Saghi Bagherzadeh,&nbsp;Mahnaz Ghaeini-Hessaroeyeh,&nbsp;Ehsan Fadaei-Kermani","doi":"10.1007/s13201-025-02406-4","DOIUrl":"10.1007/s13201-025-02406-4","url":null,"abstract":"<div><p>Cavitation is one of the primary causes of breakdown and failure on chute spillways, causing surface damage and structural destruction. In this research, a three-dimensional two-phase flow over an ogee spillway was modeled using the FLOW-3D model for the Gelevard-Neka spillway and validated with the available field data. After analyzing the hydrodynamic parameters of flow, a method was presented to predict the intensity and location of cavitation damage on the spillway surface based on the support vector machine (SVM) model. The hydraulic parameters, including flow velocity, pressure, and cavitation index, were introduced to the SVM model, and the cavitation damage level, from no damage to major damage, was predicted along the spillway structure. The validation flow results agreed well with the field data, and the normalized root-mean-square error value of 0.0196 was obtained. In the prediction of cavitation damage using the SVM model, the MAE, R, and RMSE for the training stage were, respectively, 0.32, 0.882, and 0.127, and for the testing stage were 0.024, 0.857, and 0.133. The results show reasonable performance of the SVM model in the prediction of cavitation damage. According to the results, the spillway is susceptible to cavitation damage with the most significant damage anticipated to occur in the distance range of 70–190 m from the spillway origin. Based on the importance of the aerators in protecting the spillway from cavitation damage, it is recommended to investigate the various effects of aerators on mitigating cavitation damage.</p></div>","PeriodicalId":8374,"journal":{"name":"Applied Water Science","volume":"15 4","pages":""},"PeriodicalIF":5.7,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s13201-025-02406-4.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143612139","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":"Assessment of heavy metal pollution of groundwater at the upper stream of Wadi Ranyah, Saudi Arabia, using multivariate statistical approach","authors":"Ahmed Mohamed,&nbsp;Abdullah Othman,&nbsp;Ahmed Asmaoy,&nbsp;Wael F. Galal,&nbsp;Musaab A. A. Mohammed","doi":"10.1007/s13201-025-02397-2","DOIUrl":"10.1007/s13201-025-02397-2","url":null,"abstract":"<div><p>Seventy-seven groundwater samples from Wadi Ranyah, Saudi Arabia, were analyzed to assess their physical and chemical properties. Initially, the physiochemical parameters were compared to the World Health Organization (WHO) standards and studied with Durov and Chadha diagrams. Multivariate statistical indices, such as the saturation index (SI), chloro-alkaline indices (CAI), Gibbs ratios, heavy metals pollution and evaluation indices (HPI and HEI), and the hierarchical cluster analysis (HCA), were used to identify the sources of water pollution. Durov’s diagram showed that Ca and HCO₃ ions were the dominant, and forward ion exchange was the main hydrochemical reaction. The SI results showed that the water samples were oversaturated with carbonates and in equilibrium with evaporite minerals, except for halite and sylvite. The CAI was positive in 83% of the samples, indicating forward ion exchange and Ca dominance. The Gibbs diagram showed that rock weathering (carbonate dissolution) was the dominant process controlling water chemistry. The levels of Cd, Cr, Pb, As, Hg, Li, and Mo exceeded the WHO limits in all samples, while Ni and Co exceeded the limits in 51% and 65% of the samples, respectively. The HPI and HEI results showed that the water samples were highly contaminated with heavy metals and unsuitable for consumption. The HCA showed that the main factors affecting the water salinity were dissolved carbonates, gypsum, the major ions, and some heavy metals. The HCA also showed that the main variables contributing to water salinity were dissolved carbonates, gypsum, major ions, and heavy metals. The study concluded that the water samples are not suitable for drinking and other domestic uses, and groundwater treatment measures are recommended to protect the population from serious health risks.</p></div>","PeriodicalId":8374,"journal":{"name":"Applied Water Science","volume":"15 4","pages":""},"PeriodicalIF":5.7,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s13201-025-02397-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143612090","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":"New biological treatment method of domestic wastewater with simultaneous nitrification and denitrification based on detached biofilm","authors":"Alexandru Visnevschi,&nbsp;Igor Povar","doi":"10.1007/s13201-025-02408-2","DOIUrl":"10.1007/s13201-025-02408-2","url":null,"abstract":"<div><p>The paper relates to the treatment of municipal wastewater by intensifying simultaneous nitrification and denitrification processes. The obtained results can be applied to the construction of new treatment plants as well as the upgrading of existing facilities to enhance the nitrogen removal efficiency from treated water. The developed method and corresponding installation leverage the potential of floating biofilm within activated sludge systems to initiate and sustain simultaneous nitrification and denitrification processes throughout the entire volume of the biological reactor. The floating biological film is obtained and supplied in the technological flow based on periodic aeration of the submerged biofilter compartment located in the post-aeration zone with a periodicity shorter than the residence time in the biological reactor. Nitrification achieves an efficiency of up to 99.3%. Simultaneously, denitrification occurs with an efficiency ranging from 19.9 to 91.1%, which is fundamentally correlated with the temperatures of the treated wastewater. The presence of microorganism conglomerates in the activated sludge, based on detached biofilm through an innovative method, initiates and enhances the denitrification process during continuous aeration, due to the functioning of the biological film formed by these conglomerates. Denitrification has been observed both in terms of substrate consumption of the available substrate (COD) in the aeration compartment and as a result of substrate consumption within the conglomerates formed by bacterial lysis in the anaerobic interfloccular zone, without an external carbon substrate. The denitrification process has been evaluated by analyzing the consumption of available substrate (COD) in the aeration compartments and the substrate consumption from within cocoons of microorganism conglomerates, which are formed through bacterial lysis in the anaerobic interflocular zone. This process becomes more prominent in compartments where there is a deficiency of carbon sources (COD_Cr) in the wastewater, especially at temperatures of 17.6 °C and 20.4 °C. The developed method and corresponding installation were implemented on a wastewater treatment line at the Causeni city Wastewater Treatment Plant (Republic of Moldova).</p></div>","PeriodicalId":8374,"journal":{"name":"Applied Water Science","volume":"15 4","pages":""},"PeriodicalIF":5.7,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s13201-025-02408-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143612140","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}