Energy nexus最新文献

{"title":"Water-energy nexus and GHG emissions of cropping systems under varying field management practices in arid India","authors":"Vijay Singh Rathore ,&nbsp;Narayan Singh Nathawat ,&nbsp;Seema Bhardwaj ,&nbsp;Bhagirath Mal Yadav ,&nbsp;Mahesh Kumar ,&nbsp;Ravindra Singh Shekhawat ,&nbsp;Dinesh Kumar ,&nbsp;Banwari Lal ,&nbsp;Priyanka Gautam","doi":"10.1016/j.nexus.2025.100565","DOIUrl":"10.1016/j.nexus.2025.100565","url":null,"abstract":"<div><div>Agricultural systems involve interdependencies among water, energy, food, and the environment. Understanding these linkages is crucial for developing resource-efficient systems and reducing greenhouse gas (GHG) emissions to achieve sustainability. This study evaluated energy input-output analysis and GHG emissions, and assessed the interconnections among water, energy, and GHG emissions using a nexus approach of three cropping systems [cluster bean–wheat (CB-W), cluster bean–Indian mustard (CB-IM), cluster bean–isabgol (CB-IG)]under different field management practices in arid region of India. Field management practices included two tillage types [conventional (CT), deep tillage (DT)] and three farmyard manure (FYM) application rates (0, 5, 10 Mg ha⁻¹). A cradle-to-farm gate life cycle assessment was used to estimate energy use and GHG emissions. Non-renewable inputs such as electricity, fertilizers, and diesel accounted for over 80% of total energy use, with nitrogen fertilizer, diesel, and electricity being the main sources of GHG emissions. GHG emissions were highly correlated with energy use (r² = 0.93). Diversified systems (CB-IM, CB-IG) reduced groundwater irrigation, energy use, and GHG emissions by 27.9–37.2%, 22.9–37.4%, and 20.0–46.0%, respectively, compared to the traditional CB-W system. Field management practices influenced agro-economic performance, energy efficiency, and GHG emissions. DT and FYM improved water and energy productivities. The water-energy-food-GHG nexus scores were higher for CB-IG (0.773) and CB-IM (0.507) than for CB –W (0.182), with CB-IG under DT and FYM (10 Mg ha⁻¹) achieved the highest score (0.854). These results suggest that integrating suitable field management practices (e.g. deep tillage and FYM application) with diversified cropping system can enhance sustainability by reducing water and energy use and lowering environmental impacts. This approach reduces water and energy consumption while aligning with long-term environmental and economic goals, offering valuable insights for improving agricultural management in other resource-limited regions.</div></div>","PeriodicalId":93548,"journal":{"name":"Energy nexus","volume":"20 ","pages":"Article 100565"},"PeriodicalIF":9.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145363765","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A synergistic framework integrating statistical design and machine learning for enhancing biogas yield","authors":"Yuxuan Li ,&nbsp;Mahuizi Lu ,&nbsp;Luiza C. Campos ,&nbsp;Shikun Cheng ,&nbsp;Zifu Li ,&nbsp;Yukun Hu","doi":"10.1016/j.nexus.2025.100583","DOIUrl":"10.1016/j.nexus.2025.100583","url":null,"abstract":"<div><div>Anaerobic digestion (AD) of waste-activated sludge is hindered by slow hydrolysis and complex sludge structure, which limit biogas recovery and threaten process stability. Although pretreatment methods such as microwave pretreatment (MP) have shown promise, their energy efficiency and underlying nonthermal effects remain poorly understood. In parallel, existing predictive models often neglect pretreatment conditions, restricting their applicability for process optimization. To bridge these gaps, this study proposes a synergistic framework that integrates statistical optimization with advanced machine learning (ML) to enhance biogas production from MP-assisted AD. Response Surface Methodology (RSM) identified optimal pretreatment conditions—holding time, pH, total solids (TS%), and microwave power—predicting a cumulative biogas yield (CBY) of 1020.5 mL/gVS, closely validated by experiments (1013.8 mL/gVS). These optimized datasets were further used to train ensemble ML models (AdaBoost, LightGBM, XGBoost), achieving high predictive accuracy (XGBoost R² = 0.992) with strong external validation. SHapley Additive exPlanations (SHAP) revealed TS% as the dominant factor, contrasting with RSM’s linear emphasis on microwave power, thereby highlighting nonlinear interactions and hidden effects. Complementary fluorescence microscopy and ImageJ analysis confirmed microwave-induced structural disruption of extracellular polymeric substances (EPS) and microbial accessibility, particularly at moderate power (600 W), evidencing distinct nonthermal contributions. By combining RSM’s statistical optimization with ML’s predictive and interpretive capacity, this framework not only refines operational conditions for maximum yield but also elucidates the mechanisms of MP, balancing energy input and performance. These insights support the design of more energy-efficient, scalable, and sustainable AD systems.</div></div>","PeriodicalId":93548,"journal":{"name":"Energy nexus","volume":"20 ","pages":"Article 100583"},"PeriodicalIF":9.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145571405","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhancing the sustainability of the Water-Food-Energy Nexus within an optimization framework: A case study of Ningxia, Northwest China","authors":"Jingyu Lyu ,&nbsp;Shuhong Mo ,&nbsp;Won-Ho Nam ,&nbsp;Lan Zhang ,&nbsp;Hui Sun ,&nbsp;Siyu Yan","doi":"10.1016/j.nexus.2025.100591","DOIUrl":"10.1016/j.nexus.2025.100591","url":null,"abstract":"<div><div>Water, food, and energy are essential resources for human survival and socio-economic development. The complex interconnections have positioned the Water-Food-Energy Nexus (WFEN) as a critical framework for achieving integrated and effective resource allocation, while maintaining the stable operation of coupled systems. This study, for the first time, proposes a novel WFEN-based multi-objective optimization framework that integrating system dynamics (SD) modeling, the non-dominated sorting genetic algorithm III (NSGA-III), and the weighted technique for order preference by similarity to ideal solution (TOPSIS) approach. This integrated framework enables dynamic, year-by-year optimization and comprehensive performance assessment across multiple scenarios, thereby facilitating rational resource allocation and enhancing overall system sustainability. The framework quantifies the impacts of key decision variables such as crop planting areas, irrigation quotas, and energy quotas on the system mechanisms, thereby revealing the complex coupling between feedback loops and policy regulation. A regional case study in Ningxia, northwest China, was conducted to implement and validate the proposed method. The SD model demonstrated high reliability, with simulation relative errors consistently below 10 % during the study period, indicating its suitability for representing the real-world conditions in the study area. The solution sets obtained from the multi-objective optimization exhibited substantial diversity and convergence, underscoring the effectiveness of the proposed integrated method. Under the top1 ranked solution selected by the weighted TOPSIS method, from 2011 to 2022, regional security indicators improved significantly: the Water Security Indicator (WSI) increased from 1.31 to 1.76, the Food Security Indicator (FSI) increased from 0.31 to 0.80, the Energy Security Indicator (ESI) increased from 0.51 to 1.05, and the Water-Food-Energy Security Indicator (WFESI) increased from 0.59 to 1.14. Incorporating integrated management principles into policymaking enables this study to break away from conventional single-sector policy frameworks. Moreover, by adjusting key variables that link across sectors, the proposed framework offers a promising pathway toward win-win synergies and sustainable prosperity in the regional water, agriculture, and energy systems.</div></div>","PeriodicalId":93548,"journal":{"name":"Energy nexus","volume":"20 ","pages":"Article 100591"},"PeriodicalIF":9.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145618270","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of biogas as sustainable heating alternative for poultry houses: Effects on production performance and energy efficiency","authors":"Soliman Gad ,&nbsp;Mahmoud A. El-Shazly ,&nbsp;Ayman H.A. Eissa ,&nbsp;Kamal I. Wasfy ,&nbsp;Mohammad M.H. Khan ,&nbsp;Mohammed Al-Shehri ,&nbsp;Mahmoud Moustafa ,&nbsp;Mohamed E. Abd El-Hack ,&nbsp;Alaa Awny","doi":"10.1016/j.nexus.2025.100587","DOIUrl":"10.1016/j.nexus.2025.100587","url":null,"abstract":"<div><div>This study employed an integrated methodology to evaluate the sustainability performance of a biogas-based heating system within a commercial-scale broiler house under real winter conditions in Egypt. A naturally ventilated 24 m² broiler house was equipped with a completely integrated environmental control system (ventilation, lighting, evaporative cooling, and dual heating modes). Poultry litter and farm residues were co-digested in optimized proportions with different concentrations of rumen starters to achieve maximum biogas production. The optimal combination (75% poultry litter + 25% residues + 50% starter) was then employed to substitute electric heating in the poultry house with two ventilation time intervals (3 and 5 min). The combined system resolved waste management, renewable energy production, and environmental regulation in parallel. Maximum daily biogas yield was 25.6 L/day with up to 85.6% methane content providing thermal efficiencies of 850 MJ/day. Biogas heating provided thermal stability and reduced temperature–humidity index scores compared to electric heating, especially with 5-min ventilation, enhancing bird welfare. Broilers reached 10% higher final body weight (2.4 kg) and 25% improved feed conversion ratio (1.2) compared to electric heating. Total and specific energy utilization decreased to 1.4 kWh and 0.6 kWh/kg, respectively, while production cost decreased by up to 30% and the net profit increased to 0.80 USD/kg. By on-site valorization of waste, renewable energy supply, and climate optimization, this study demonstrates a novel, field-scale strategy to sustainable poultry production. The findings affirm that biogas technology could consistently counteract dependence on fossil fuels, lower the expense, and increase productivity, presenting an expandable pathway toward circular and climate-resilient livestock farming.</div></div>","PeriodicalId":93548,"journal":{"name":"Energy nexus","volume":"20 ","pages":"Article 100587"},"PeriodicalIF":9.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145618267","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modeling and operation of water-energy microgrids considering resilience assessment","authors":"Hasan Masrur ,&nbsp;Ali T. Al-Awami ,&nbsp;Yasser Almoghathawi","doi":"10.1016/j.nexus.2025.100590","DOIUrl":"10.1016/j.nexus.2025.100590","url":null,"abstract":"<div><div>The increasing global water scarcity and energy supply disruptions pose substantial challenges to water-energy infrastructure resilience. While most previous studies addressed either the economic operation or resilience of water-energy systems separately, this work uniquely integrates reverse osmosis (RO) desalination, renewable-rich microgrid optimization, and quantitative resilience assessment within a unified Mixed-Integer Linear Programming (MILP) and Kaplan–Meier (KM) survival analysis framework. This integration fills a critical research gap in modeling how High-Impact Low- Probability (HILP) events jointly affect both water and power subsystems. The proposed model minimizes lifecycle costs while evaluating system survivability under extreme disruptions, incorporating photovoltaic (PV) generation, combined heat and power (CHP) units, battery storage, and grid interactions. Simulation results for a hospital-scale case study show an approximately 13 % reduction in total operating cost and a 22 % improvement in the resilience index relative to a baseline without desalination integration. The findings demonstrate that coupling desalination with renewable-rich microgrids significantly enhances both economic efficiency and system resilience under HILP scenarios, offering a robust framework for sustainable, resilient water-energy systems.</div></div>","PeriodicalId":93548,"journal":{"name":"Energy nexus","volume":"20 ","pages":"Article 100590"},"PeriodicalIF":9.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145618265","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluating the energy-water-food nexus in Qatar: Balancing crop imports and local production","authors":"Sa’d Shannak ,&nbsp;Raka Jovanovic ,&nbsp;Antonio Sanfilippo ,&nbsp;Sarah Namany ,&nbsp;Abdellah Kafi ,&nbsp;Tareq Al-Ansari","doi":"10.1016/j.nexus.2025.100568","DOIUrl":"10.1016/j.nexus.2025.100568","url":null,"abstract":"<div><div>Agriculture accounts for approximately 70 % of the global water demand and 30 % of the global energy demand. Finding an optimal balance in the provi- sion of food through imports or local production is therefore crucial in secur- ing energy and water sustainability. The literature on this subject has mostly focused on either local production or import strategies, and there is a need to integrate these elements into a unified framework. We address this need by developing a novel mathematical model that performs a nuanced analysis of self-sufficiency rates, price differentials, and import patterns through the integration of economic, environmental, and policy constraints. The ensu- ing analysis offers an evaluation of energy and water sustainability in the light of trade-offs between food imports vs. local production. Considering factors such as the energy required for water pumping in local crop produc- tion and the water footprint in the importing countries, the model elucidates the water and energy demands associated food imports and local production evaluating trade-offs between local production and imports. Results reveal that in scenarios with three import partners, the optimal distributions are consistently 40 %, 30 %, and 30 % when minimizing cost based on 2022 prices. However, with more import partners, distribution becomes price-dependent, indicating a need for enhanced government coordination and a more holistic approach to balancing local production and imports that accounts for energy and water resource constraints.</div></div>","PeriodicalId":93548,"journal":{"name":"Energy nexus","volume":"20 ","pages":"Article 100568"},"PeriodicalIF":9.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145417706","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Coupling coordination and driving factors of the water-energy-food nexus in China: A sustainable development perspective","authors":"Zhili Lu,&nbsp;Shipeng Yang,&nbsp;Weiwei Chen,&nbsp;Lei Lu,&nbsp;Yunjiao Fan,&nbsp;Chaoyang Yue,&nbsp;Yan Shi","doi":"10.1016/j.nexus.2025.100545","DOIUrl":"10.1016/j.nexus.2025.100545","url":null,"abstract":"<div><div>Water, energy, and food (WEF) are crucial for human survival, making studying the WEF nexus in China vital for sustainable development. This work proposes an evaluation indicator system and analyzes the comprehensive evaluation level, coupling coordination degree (CCD), and spatiotemporal evolution using the comprehensive evaluation model and CCD model. A spatial autocorrelation model is used to examine the CCD across 30 regions of China. Additionally, the geographic spatio-temporal weighted model (GTWR) and geographical detector model are used to pinpoint the driving factors affecting the CCD of the WEF nexus. The results reveal a steady improvement in WEF nexus coordination nationwide, accompanied by significant regional disparities. While eastern provinces exhibit higher and earlier coordination levels, central regions show accelerated progress, and western provinces remain constrained by resource endowments. Moreover, the driving factors of CCD demonstrate pronounced spatial–temporal heterogeneity, with expenditure on R&amp;D funding, disposable income per capita, and GDP growth rate exerting varying influences across provinces and over time. Based on these results, recommendations are made to strengthen food production, promote clean energy development, and optimize water resource structures to enhance the WEF nexus across provinces in China.</div></div>","PeriodicalId":93548,"journal":{"name":"Energy nexus","volume":"20 ","pages":"Article 100545"},"PeriodicalIF":9.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145160153","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tracer solubility, stability, and reactivity in ultramafic rocks: Enhancing CCS and mineralization monitoring efficiency","authors":"Hammad Tariq Janjuhah ,&nbsp;Sulaiman Al Mani ,&nbsp;Juerg M Matter","doi":"10.1016/j.nexus.2025.100539","DOIUrl":"10.1016/j.nexus.2025.100539","url":null,"abstract":"<div><div>Artificial tracers have been widely used in hydrogeology to identify groundwater flow pathways and to quantify mixing, and chemical and biological reaction processes. De- pending on the specific environment, tracers behave differently and can be subject to chemical interaction. This research investigated the adsorption characteristics of two common artificial tracers, fluorescein (FL) and Na-Naphthenate-Methylene Blue (Na-Napth-MB), dissolved in different types of water and on serpentinized peridotite rock under ambient conditions with emphasis on applications in carbon capture and storage (CCS) and CO₂ mineralization. Using the prepared 1 ppm fluorescein and 5 ppm Na- Naphthenate -MB solutions, investigations were carried out for their reactivity and stability in freshwater, sea- water, soda water, and serpentinized peridotite rock. The data indicate that lower concentration of FL promoted higher adsorption than in higher concentrations; this effect declined with higher concentration/dosage. Whereas Na-Napth-MB showed much higher adsorption even in high dosage concentrations. In addition, contrary to the assumption that such tracers would remain non-reactive with other rock types, it was observed that ultramafic rocks (e.g. serpentinized peridotite) were significantly adsorbing. When the adsorption of an in-situ condition is considered, it is rather assumed that the adsorption potential will be very high and might get even 10 times higher than the values determined in the laboratory. This indicates that there is a need for careful selection of appropriate artificial tracers, their concentrations, and their effective monitoring in subsurface applications such as CCS. This makes it necessary to consider alternative conservative tracers such as e.g. noble gases, perfluorocarbons or nanoparticles for CCS projects. The outcomes are important to im- prove the tracer-based monitoring techniques for ultramafic rocks to accomplish long-term tracking of CO₂ and mineralization.</div></div>","PeriodicalId":93548,"journal":{"name":"Energy nexus","volume":"20 ","pages":"Article 100539"},"PeriodicalIF":9.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145223176","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Environmental and damage assessment of electric vehicles compared to internal combustion engine vehicles under various ambient temperature scenarios using the LCA approach","authors":"Mohammadali Allahrabbi Shirazi,&nbsp;Rahim Zahedi,&nbsp;Hossein Yousefi,&nbsp;Alireza Aslani","doi":"10.1016/j.nexus.2025.100606","DOIUrl":"10.1016/j.nexus.2025.100606","url":null,"abstract":"<div><div>This study assesses the environmental impacts of the energy consumption of electric vehicles (EVs) and internal combustion engine vehicles (ICEVs) using a life cycle assessment (LCA) approach considering four temperature scenarios. The aim is to compare the environmental performance of the energy consumption of both vehicle types under different climatic conditions and to identify the most sustainable option. The functional unit for this study was set at 100 km of distance. The results show that temperature significantly affects the environmental impacts of EVs and ICEVs. EVs operating at warmer temperatures (30 °C) showed lower environmental impacts compared to those operating at colder temperatures (-7 °C). The third EV scenario with renewable wind energy at 30 °C produced 90 % less CO₂ emissions than the third ICEV scenario at the same temperature (0.3318 kg CO_2eq per 100 km, compared to 3.3372 kg CO_2eq). In addition, EVs showed lower impacts in key categories such as human health, particulate matter formation and resource depletion. ICEV scenarios, especially at lower temperatures, showed higher greenhouse gas emissions and environmental loads. The findings suggest that electric vehicles, especially when powered by renewable energy sources and operated under optimal temperature conditions, offer significant environmental benefits over ICEVs. This study highlights the importance of considering temperature and energy sources when assessing the environmental performance of vehicles and provides valuable insights for future vehicle design and policymaking aimed at reducing the environmental impacts associated with transportation. Policy recommendations include optimizing charging infrastructure in cold regions and promoting EVs in warmer climates.</div></div>","PeriodicalId":93548,"journal":{"name":"Energy nexus","volume":"20 ","pages":"Article 100606"},"PeriodicalIF":9.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145618272","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimized biohydrogen production from sewage sludge: Advanced pretreatment strategies in dark fermentation and microbial electrolysis cells","authors":"Hikmatullah Ahmadi ,&nbsp;Anam Jalil ,&nbsp;Sohail Khan ,&nbsp;Ndayisenga Fabrice ,&nbsp;Chengyu Zhang ,&nbsp;Zhisheng Yu","doi":"10.1016/j.nexus.2025.100573","DOIUrl":"10.1016/j.nexus.2025.100573","url":null,"abstract":"<div><div>The production of biohydrogen from sewage sludge presents a promising avenue for sustainable energy conversion and pollution control. This study systematically evaluates biohydrogen (bio-H₂) production through dark fermentation (DF) and single-chamber microbial electrolysis cells (MECs), employing diverse substrate pretreatment methods, including acidic, ultrasonic, heat, alkaline, and a novel combined CalciumCarbonate-2Potassiumhydroxide (CCPH) pretreatment. The findings reveal that these pretreatments significantly enhance the accumulation of proteins, carbohydrates, and volatile fatty acids (VFAs), with the DF phase further augmenting the solubilization of these critical components. Notably, 90–95% of carbohydrate and protein accumulation occurs during the pretreatment phase, which concurrently suppresses methanogenesis in sewage sludge, thereby optimizing conditions for bio-H₂ production in subsequent MEC processes. Among the pretreatments, CCPH-P demonstrates exceptional performance, achieving a total volatile fatty acid (TVFAs) concentration of 1,962 ± 124 mg/L post-dark fermentation, representing an 11.4-fold increase compared to untreated sludge. In MEC experiments, CCPH-P sludge attains a maximum current density of 172.5 A/m³ and an average bio-H₂ yield of 133.071 ml/g VS, underscoring its efficiency in electrochemical hydrogen recovery. Acetic and propionic acids, derived from sludge fermentation, emerge as the predominant electron donors, constituting approximately 80% of the total VFAs content across all pretreated substrates. Metagenomic analysis further reveals that Firmicutes exhibit the highest relative abundance, ranging from 60% to 88% in pretreated substrates, compared to merely 10.5% in untreated sewage sludge. These results collectively indicate that CCPH-pre-treatment serves as a viable and efficient method for enhancing biohydrogen recovery from sewage sludge through DF and MEC systems, thereby advancing the potential for waste-to-energy applications.</div></div>","PeriodicalId":93548,"journal":{"name":"Energy nexus","volume":"20 ","pages":"Article 100573"},"PeriodicalIF":9.5,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145363707","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}