{"title":"Independent component analysis in wastewater treatment plants: Unlocking process understanding and performance optimization","authors":"Zikang Chen, Xinyuan Wang, Hongbin Liu","doi":"10.1016/j.jwpe.2025.108647","DOIUrl":"10.1016/j.jwpe.2025.108647","url":null,"abstract":"<div><div>Independent component analysis (ICA) has emerged as a powerful tool for extracting statistically independent and non-Gaussian features from complex, multivariate process data, offering distinct advantages for data-driven wastewater treatment under challenging operating conditions. Wastewater treatment plants often face abrupt hydraulic and organic load fluctuations, sensor fouling and drift, and strongly nonlinear, nonstationary microbial dynamics—factors that degrade the performance of conventional linear methods. This review provides a comprehensive synthesis of ICA's theoretical foundations and key algorithmic variants, including FastICA, Kernel ICA, Dynamic ICA, Sparse ICA, and Online ICA, with emphasis on their respective strengths, limitations, and suitability for different operational scenarios. Practical applications are critically evaluated across four core domains: process monitoring, fault diagnosis, soft sensing, and parameter control. ICA has demonstrated strong potential for isolating latent signals, improving process interpretability, enabling early anomaly detection, and enhancing the estimation of unmeasured variables in wastewater systems. Persistent challenges—including kernel sensitivity, computational demands, and vulnerability to streaming noise—remain barriers to large-scale and real-time deployment. Addressing these gaps, emerging research is exploring hybrid ICA–deep learning frameworks, adaptive kernel learning, reinforcement learning–based control, and self-tuning dynamic ICA for online environments. By linking algorithmic innovation to the specific engineering challenges of wastewater treatment, this review offers an integrated perspective on ICA's current capabilities and outlines promising pathways toward intelligent, resilient, and sustainable plant operation<strong>.</strong></div></div>","PeriodicalId":17528,"journal":{"name":"Journal of water process engineering","volume":"78 ","pages":"Article 108647"},"PeriodicalIF":6.7,"publicationDate":"2025-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144997817","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mohd Azam Mohd Adnan , Mohd Fadhil Majnis , Mohd Arif Mat Norman , Mohd Darnalis A. Rahman , Mohd Rafie Johan , Nurhidayatullaili Muhd Julkapli
{"title":"Visible-light-activated TiO2/ZnO-chitosan catalyst for photodegradation of methylene blue dye: An experimental and predictive modelling using artificial neural networks","authors":"Mohd Azam Mohd Adnan , Mohd Fadhil Majnis , Mohd Arif Mat Norman , Mohd Darnalis A. Rahman , Mohd Rafie Johan , Nurhidayatullaili Muhd Julkapli","doi":"10.1016/j.jwpe.2025.108423","DOIUrl":"10.1016/j.jwpe.2025.108423","url":null,"abstract":"<div><div>The aim of this study was to address the limitations of titanium dioxide (TiO<sub>2</sub>) nanoparticles as photocatalysts, specifically their ultra violet light responsiveness, wide bandgap, and rapid electron/hole recombination. To overcome these challenges, the acidic mixing method has been employed to develop a hybrid titanium dioxide and zinc oxide (ZnO) photocatalyst supported by chitosan (CS). The resulting TiO<sub>2</sub>/ZnO/CS composite exhibited synergistic effects on its crystalline properties and textured surface, resulting in a reduced bandgap of 2.63 eV. The synergistic interactions between –OH, –NH<sub>2</sub>, TiO<sub>2</sub>, and ZnO groups were confirmed. Addition of ZnO to the TiO<sub>2</sub> matrix reduces photoluminescence, showing better charge separation and less electron-hole recombination due to efficient charge transfer between them. Under visible light, the 1: 2:1 ratio of TiO<sub>2</sub>, ZnO, and CS achieved nearly complete dye degradation within 90 min. The TiO<sub>2</sub>/ZnO/CS catalyst maintained high efficiency over four usage cycles, reaching 89 % efficiency in the fourth cycle. Simulated using an Artificial Neural Network Model, this photocatalyst shows promise for sustainable, low-cost degradation of synthetic dyes.</div></div>","PeriodicalId":17528,"journal":{"name":"Journal of water process engineering","volume":"77 ","pages":"Article 108423"},"PeriodicalIF":6.7,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144750046","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xiang Gong , Suqi Li , Xiulan Guo , Jiaqiao Yuan , Hongyu Lu , Shuming Wen , Pan Yu , Shaojun Bai , Dandan Wu
{"title":"Efficiency removal and mechanism of xanthate from flotation tailings wastewater via simulated acid mine drainage (AMD) activate H2O2 oxidization","authors":"Xiang Gong , Suqi Li , Xiulan Guo , Jiaqiao Yuan , Hongyu Lu , Shuming Wen , Pan Yu , Shaojun Bai , Dandan Wu","doi":"10.1016/j.jwpe.2025.108431","DOIUrl":"10.1016/j.jwpe.2025.108431","url":null,"abstract":"<div><div>This work investigates the efficiency removal and mechanism of xanthate from flotation tailings wastewater through a coagulation-Fenton oxidation process by introducing Fe<sup>2+</sup> and Mn<sup>2+</sup> to activate H<sub>2</sub>O<sub>2</sub>. Under the conditions of initial 60 mg/L SBX concentration, 50 mg/L H<sub>2</sub>O<sub>2</sub> concentration, 25 mg/L Fe<sup>2+</sup> concentration, 25 mg/L Mn<sup>2+</sup> concentration, 3.5 initial pH, and 60 min reaction time, the degradation rate of xanthate was more than 98 %. The H<sub>2</sub>O<sub>2</sub> + Fe<sup>2+</sup>+Mn<sup>2+</sup> system exhibits markedly superior degradation efficiency for SBX. The results demonstrate that the Fe<sup>2+</sup>+Mn<sup>2+</sup> bimetallic system in simulated AMD facilitates the activation of H<sub>2</sub>O<sub>2</sub> to generate a greater abundance of hydroxyl radicals (•OH). Through characterization of degradation products and analysis of intermediates, two potential degradation pathways of SBX are proposed. In the first pathway, SBX initially undergoes conversion to BPX, which subsequently degrades into small molecular compounds including CO<sub>2</sub>, H<sub>2</sub>O, and SO<sub>4</sub><sup>2−</sup> under sustained •OH radical attack. The secondary pathway involves the formation of precipitates composed of xanthates metal (Fe/Mn), iron oxides, and manganese oxides. This work presents a new strategy for efficiently degrading xanthate contaminants in mineral flotation wastewater. It also valorizes AMD by exploiting its intrinsic properties, thereby mitigating AMD's environmental hazards at the source.</div></div>","PeriodicalId":17528,"journal":{"name":"Journal of water process engineering","volume":"77 ","pages":"Article 108431"},"PeriodicalIF":6.7,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144749859","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Sulfite-synergized VUV photolytic decomposition of metformin: A combined experimental and theoretical study","authors":"Yurong Gu , Zijun Dong , Qi Han , Liao Ouyang , Yihua Chen","doi":"10.1016/j.jwpe.2025.108443","DOIUrl":"10.1016/j.jwpe.2025.108443","url":null,"abstract":"<div><div>Metformin (MET), widely used in the treatment of type П diabetes, may pose a threat to environmental security when extensively used and improperly disposed of. This study aimed to provide a comprehensive and deeper understanding of MET decomposition under UV<sub>185</sub> (vacuum ultraviolet, VUV) photolytic treatment in the presence of sulfite (SO<sub>3</sub><sup>2−</sup>). A noticeable MET decomposition efficiency of 98.3 % was observed at pH 9, accompanied by a fast pseudo-first-order rate constant of 0.0459 min<sup>−1</sup> in the VUV/SO<sub>3</sub><sup>2−</sup> treatment system. Radical scavenging experiments and electron paramagnetic resonance analysis confirmed that MET decomposition was primarily initiated by the attack of hydrated electron (e<sub>aq</sub><sup>−</sup>) generated from SO<sub>3</sub><sup>2−</sup> under VUV irradiation. Time-of-flight mass spectrometry results, supported by density functional theory and wave function analysis, indicated four parallel pathways for the reductive decomposition of MET in the VUV/SO<sub>3</sub><sup>2−</sup> treatment system. Demethylation and scission of C<img>N bonds within the guanidine moiety were identified as the primary mechanisms underlying MET decomposition in this system. A substantial reduction in MET biotoxicity was observed following treatment using the VUV/SO<sub>3</sub><sup>2−</sup> reduction system. The effects of treatment parameters and common water matrix components were meticulously investigated.</div></div>","PeriodicalId":17528,"journal":{"name":"Journal of water process engineering","volume":"77 ","pages":"Article 108443"},"PeriodicalIF":6.7,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144750047","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Investigating log removals of bacteria and viruses at a full-scale enhanced coagulation contact filtration drinking water treatment plant","authors":"Paula Pellikainen , Bjørnar Eikebrokk , Mette Myrmel , Elin Lavonen","doi":"10.1016/j.jwpe.2025.108393","DOIUrl":"10.1016/j.jwpe.2025.108393","url":null,"abstract":"<div><div>The effectiveness of pathogen removal from drinking water by conventional treatment has been evaluated in numerous studies. However, the reported log removals show a significant variation, depending on the source water quality, type of microorganism being studied, scale of experiments (laboratory, pilot, or full-scale), treatment operation conditions, and differences in treatment technology and process design. Additionally, data on the removal of bacteria and viruses using full-scale enhanced coagulation-contact filtration processes are very limited, and there is no available information on log removal rates under stressed conditions. In this study, the removal of spiked <em>Enterococcus faecium</em> (<em>E. faecium</em>) (ATCC® 8459™) and MS2 was investigated at a full-scale enhanced coagulation-contact filtration water treatment plant during optimal and stressed operational conditions. The log removals achieved under optimal coagulation conditions were ≥4.6 for <em>E. faecium</em>, ≥2.1 for infectious MS2 (PFU), and, on average, >2.3 for total MS2 (RT-qPCR), with variation ranging from 1 to >3.5 logs. The removal of naturally occurring coliforms was >3.4 logs. During suboptimal coagulation conditions, the concentration of <em>E. faecium</em> and total MS2 increased in the filter effluent. The removal for <em>E. faecium</em> was ≥4.1 logs, and the average total MS2 decreased by >1.8. Operational stress, such as increased filtration rates, reduced virus removal by over 2 logs. Compared to conventional treatment, the results suggest that enhanced coagulation-contact filtration is less sensitive to short-term stress and suboptimal operational conditions. The results of this study highlight the importance of optimizing operational conditions to ensure effective treatment barriers and safe drinking water.</div></div>","PeriodicalId":17528,"journal":{"name":"Journal of water process engineering","volume":"77 ","pages":"Article 108393"},"PeriodicalIF":6.7,"publicationDate":"2025-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144750041","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Low-energy light-activated Sn2+-SnO2/TiO2 photocatalyst for water pollutant removal","authors":"Haroki Madani , Saepurahman","doi":"10.1016/j.jwpe.2025.108425","DOIUrl":"10.1016/j.jwpe.2025.108425","url":null,"abstract":"<div><div>A combination of doping and constructing a heterostructure is believed to be an effective strategy to decrease the band gap and enhance the charge separation efficiency of the SnO<sub>2</sub> photocatalyst to make it suitable for pollution treatment under solar irradiation. In this study, Sn<sup>2+</sup>-SnO<sub>2</sub> was combined with TiO<sub>2</sub> to create a Sn<sup>2+</sup>-SnO<sub>2</sub>/TiO<sub>2</sub> heterostructure using a sol-hydrothermal method. XRD, SEM, TEM, Raman, XPS, and DRS characterization showed that Sn(II) doped SnO<sub>2</sub> with a particle size of 3.85 ± 0.85 nm formed a heterostructure with amorphous TiO<sub>2</sub>, narrowing the band gap down to 2.35 eV. Sn<sup>2+</sup>-SnO<sub>2</sub>/TiO<sub>2</sub> exhibits better performance than Sn<sup>2+</sup>-SnO<sub>2</sub>, with kinetic constants 3.8 times higher for MO degradation and 2.2 times higher for Cr(VI) ion removal, respectively. Complete degradation of methyl orange (MO) was achieved within 20 min, while hexavalent chromium (Cr(VI)) was entirely reduced to trivalent chromium (Cr(III)) within 60 min under simulated solar light irradiation (λ ≥ 450 nm). The photocatalysis mechanism and the involved ROS were also investigated.</div></div>","PeriodicalId":17528,"journal":{"name":"Journal of water process engineering","volume":"77 ","pages":"Article 108425"},"PeriodicalIF":6.7,"publicationDate":"2025-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144750042","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Bayan Khojah , Salima Sadeghi , Lubos Polerecky , Jack J. Middelburg , Dick van Oevelen , Marcel T.J. van der Meer , Thilo Behrends
{"title":"Organic carbon uptake and mineralization in slow sand filters and their relation to process variables","authors":"Bayan Khojah , Salima Sadeghi , Lubos Polerecky , Jack J. Middelburg , Dick van Oevelen , Marcel T.J. van der Meer , Thilo Behrends","doi":"10.1016/j.jwpe.2025.108396","DOIUrl":"10.1016/j.jwpe.2025.108396","url":null,"abstract":"<div><div>Slow sand filtration (SSF) is a widely used biofiltration method for drinking water treatment, yet quantitative measures of biological activity, specifically in terms of carbon uptake and mineralization, are not well established. This study assessed biological activity in mature SSF systems operated by three Dutch drinking water companies using carbon concentration measurements, isotopic signature analyses, and <sup>13</sup>C-labeled glucose tracer experiments. Our results revealed measurable differences in carbon concentrations and isotopic signatures between influent and effluent waters. Specifically, DOC concentrations decreased by up to 0.13 mmol L<sup>−1</sup>, while DIC concentrations increased by up to 0.84 mmol L<sup>−1</sup>. Additionally, δ<sup>13</sup>C-DOC and δ<sup>13</sup>C-DIC values exhibited shifts of up to +1.9 ‰ and 2.9 ‰, respectively, indicative of carbon uptake and mineralization. Biological activity varied across filters, as reflected in the time required for complete removal of glucose, which ranged from 5 to over 48 h and correlated with assimilable organic carbon (AOC) removal rates. AOC loading appeared to be the primary driver of bioactivity, with the lowest activity found in a filter fed with dune-infiltrated water and the highest in a filter receiving ozonated influent water. These findings highlight the importance of considering source water characteristics and the preceding treatment chain to understand their potential impact on biological activity in SSF.</div></div>","PeriodicalId":17528,"journal":{"name":"Journal of water process engineering","volume":"77 ","pages":"Article 108396"},"PeriodicalIF":6.7,"publicationDate":"2025-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144749861","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ying Yuan , Quanhong Chen , Yinghui Tang , Qiming Cheng , Gaoju Zou , Xiaoke Lian , Zhen Liu , Hongjun Xiao , Mingyue Liu , Kaifeng Wang , Shixin Zhang , Yao Chen
{"title":"Hybrid machine learning model with SHAP interpretability for optimization of targeted nitrogen and phosphorus removal from bioretention systems","authors":"Ying Yuan , Quanhong Chen , Yinghui Tang , Qiming Cheng , Gaoju Zou , Xiaoke Lian , Zhen Liu , Hongjun Xiao , Mingyue Liu , Kaifeng Wang , Shixin Zhang , Yao Chen","doi":"10.1016/j.jwpe.2025.108417","DOIUrl":"10.1016/j.jwpe.2025.108417","url":null,"abstract":"<div><div>Bioretention systems (BRS), while effective in stormwater management, exhibit inconsistent nutrient removal performance due to complex interactions between design parameters and environmental conditions. To address the lack of predictive tools based on data-driven models, this study compiled a unified dataset from 61 peer-reviewed publications (1052 experimental samples), and systematically evaluated four machine learning algorithms: multiple linear regression (MLR), random forest (RF), gradient boosting (XGB), and hybrid RF-tuned XGB (RF + XGB). These models were trained to predict the effluent concentrations of nutrients using design and environmental variables as inputs. The hybrid RF + XGB model demonstrated superior accuracy, achieving test-phase R<sup>2</sup> value of 0.74–0.85 for nitrogen species (NH<sub>4</sub><sup>+</sup>-N, NO<sub>3</sub><sup>−</sup>-N, TN) and 0.66 for TP. SHapley Additive exPlanation (SHAP), partial dependency plots (PDPs), and SHAP force plots analyses identified critical operational thresholds for nutrient removal. NH<sub>4</sub><sup>+</sup>-N removal was peaked at inflow flux (IF) of 380–400 mm, an antecedent dry weather period (ADWP) of 2–3 days, and a mineral content (MC) of 15 %–25 %. NO<sub>3</sub><sup>−</sup>-N removal was optimal under conditions of ADWP = 3–4 days, with 3 % organic and 60 %–90 % sand content. TN removal depended on synergistic interactions when IF <400 mm, coupled with 2 % organic and 5 % mineral content. TP removal was significantly correlated with high influent concentrations (C<sub>in</sub> > 3 mg/L), an appropriate IF range of 100–400 mm, and enhanced mineral-mediated adsorption. These findings reveal the dominance of media composition (organic/mineral ratios) and hydraulic control in nutrient removal, providing actionable insights for optimizing BRS designs through data-driven strategies.</div></div>","PeriodicalId":17528,"journal":{"name":"Journal of water process engineering","volume":"77 ","pages":"Article 108417"},"PeriodicalIF":6.7,"publicationDate":"2025-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144724427","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ismail Marouani , Ali B.M. Ali , Mona Mohammad Al-Amari , Zaina Algarni , Noura Almadani , Abdelfattah Amari , Hanaa A. Nofal , Alisher Abduvokhidov , Mukhtorjon Karimov
{"title":"Dual-functional biomass-derived carbon-supported CoTiO3-ZnO heterojunction for photocatalytic degradation of antibiotic pollutants and H2 production: Analytical characterization and toxicity evaluation","authors":"Ismail Marouani , Ali B.M. Ali , Mona Mohammad Al-Amari , Zaina Algarni , Noura Almadani , Abdelfattah Amari , Hanaa A. Nofal , Alisher Abduvokhidov , Mukhtorjon Karimov","doi":"10.1016/j.jwpe.2025.108430","DOIUrl":"10.1016/j.jwpe.2025.108430","url":null,"abstract":"<div><div>Photocatalysis offers a sustainable route for addressing the dual challenges of environmental pollution and renewable energy production. This study reports synthesizing and optimizing a novel Biochar-supported CoTiO₃-ZnO Z-scheme heterojunction photocatalyst derived from sour cherry stone biomass. Integrating Biochar (BC) enhances surface area, charge separation, and pollutant adsorption, leading to superior photocatalytic activity under visible light. Composites with varying BC content were prepared and systematically optimized via response surface methodology (RSM) using a combined sol-gel and hydrothermal method. The optimized photocatalyst exhibited over 95 % degradation efficiency of the antibiotic ofloxacin (OFL) and simultaneous hydrogen evolution rates up to 750 μmol g<sup>−1</sup> h<sup>−1</sup> under visible light irradiation. Mechanistic investigations confirmed that superoxide radicals and photogenerated holes predominantly mediate OFL degradation, while electrons facilitate proton reduction to hydrogen. LC-MS analysis identified multiple degradation intermediates and toxicity assessments demonstrated significant detoxification of OFL byproducts. Furthermore, the catalyst maintained high stability and reusability across multiple cycles without considerable activity loss. These findings highlight the potential of biomass-derived carbon-supported CoTiO₃-ZnO heterojunctions as efficient, dual-functional photocatalysts for integrated wastewater treatment and green hydrogen production, contributing to sustainable environmental and energy solutions.</div></div>","PeriodicalId":17528,"journal":{"name":"Journal of water process engineering","volume":"77 ","pages":"Article 108430"},"PeriodicalIF":6.7,"publicationDate":"2025-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144749860","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Effect of liquid and solid separation of post-thermochemically treated digested sludge on energy and material balances of sludge anaerobic digestion","authors":"Xiao Xu, Thomas Dockhorn","doi":"10.1016/j.jwpe.2025.108438","DOIUrl":"10.1016/j.jwpe.2025.108438","url":null,"abstract":"<div><div>Anaerobically digested sludge (DS) is usually disposed of after dewatering. Due to the significant amount of organic matters in DS, the thermal alkaline process (TAP) and liquid/solid separation are considered suitable methods to enhance the solubilization of organic matters into the liquid fraction for biogas production and improve also the sludge dewaterability. DSs from 7 wastewater treatment plants (WWTPs) were treated under 160 °C (6 bar) for 30 min with a previous pH adjustment and then centrifuged for liquid and solid separation. The liquid fraction was digested for biogas production and the solid fraction was disposed of. The liquid fraction achieved its maximum biogas production under TAP at pH 9 with 175 ± 17 L/kg COD<sub>total</sub>. The biogas production in the 7 WWTPs could be improved by 251–3233 m<sup>3</sup>/d with liquid fraction digestion, and a net electricity production of 420–5402 kWh<sub>el</sub>/d could be achieved. Besides, the discharged dewatered DS volume decreased by 50–70 %.</div></div>","PeriodicalId":17528,"journal":{"name":"Journal of water process engineering","volume":"77 ","pages":"Article 108438"},"PeriodicalIF":6.7,"publicationDate":"2025-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144749862","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}