{"title":"Making Waves: Conductive Materials in Anaerobic Digestion: A Sustainable Pathway or a Hidden Carbon Burden?","authors":"Yifeng Feng, Yi Han, Liezhong Fan, Xiejuan Lu, Xiaohui Wu, Guanghao Chen, Feixiang Zan","doi":"10.1016/j.watres.2025.124718","DOIUrl":null,"url":null,"abstract":"Conductive material-mediated anaerobic digestion (AD) systems offer a promising solution to enhance methane production, yet its sustainability and economic viability require holistic evaluation. In this study, we systematically assess the typical conductive materials, namely, biochar, iron-based material, and biochar-iron composites, through integrated life cycle and cost-benefit analyses of 219 experimental cases. Biochar-iron composites achieved the highest methane yield improvement (36%), while iron-based materials posed significant carbon burdens (contributing up to 44% of system emissions). Crucially, material recycling (five cycles) reduced iron's carbon footprint by 72%, and digestate valorization into biochar further lowered net emissions by 113.8-184.9%. Economically, iron-based materials outperformed biochar in profitability (220 USD/ton volatile solids (VS)), and combining material recovery with digestate valorization boosted net profits by 191.8-264.8%. The findings demonstrate that prioritizing biochar-iron composites for performance and iron-based materials with recovery for cost-effectiveness, alongside closed-loop design, can reconcile environmental and economic goals. This work provides actionable pathways to optimize conductive material-enhanced AD systems for scalable, sustainable waste-to-energy conversion.","PeriodicalId":443,"journal":{"name":"Water Research","volume":"5 1","pages":""},"PeriodicalIF":12.4000,"publicationDate":"2025-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Water Research","FirstCategoryId":"93","ListUrlMain":"https://doi.org/10.1016/j.watres.2025.124718","RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENGINEERING, ENVIRONMENTAL","Score":null,"Total":0}
引用次数: 0
Abstract
Conductive material-mediated anaerobic digestion (AD) systems offer a promising solution to enhance methane production, yet its sustainability and economic viability require holistic evaluation. In this study, we systematically assess the typical conductive materials, namely, biochar, iron-based material, and biochar-iron composites, through integrated life cycle and cost-benefit analyses of 219 experimental cases. Biochar-iron composites achieved the highest methane yield improvement (36%), while iron-based materials posed significant carbon burdens (contributing up to 44% of system emissions). Crucially, material recycling (five cycles) reduced iron's carbon footprint by 72%, and digestate valorization into biochar further lowered net emissions by 113.8-184.9%. Economically, iron-based materials outperformed biochar in profitability (220 USD/ton volatile solids (VS)), and combining material recovery with digestate valorization boosted net profits by 191.8-264.8%. The findings demonstrate that prioritizing biochar-iron composites for performance and iron-based materials with recovery for cost-effectiveness, alongside closed-loop design, can reconcile environmental and economic goals. This work provides actionable pathways to optimize conductive material-enhanced AD systems for scalable, sustainable waste-to-energy conversion.
期刊介绍:
Water Research, along with its open access companion journal Water Research X, serves as a platform for publishing original research papers covering various aspects of the science and technology related to the anthropogenic water cycle, water quality, and its management worldwide. The audience targeted by the journal comprises biologists, chemical engineers, chemists, civil engineers, environmental engineers, limnologists, and microbiologists. The scope of the journal include:
•Treatment processes for water and wastewaters (municipal, agricultural, industrial, and on-site treatment), including resource recovery and residuals management;
•Urban hydrology including sewer systems, stormwater management, and green infrastructure;
•Drinking water treatment and distribution;
•Potable and non-potable water reuse;
•Sanitation, public health, and risk assessment;
•Anaerobic digestion, solid and hazardous waste management, including source characterization and the effects and control of leachates and gaseous emissions;
•Contaminants (chemical, microbial, anthropogenic particles such as nanoparticles or microplastics) and related water quality sensing, monitoring, fate, and assessment;
•Anthropogenic impacts on inland, tidal, coastal and urban waters, focusing on surface and ground waters, and point and non-point sources of pollution;
•Environmental restoration, linked to surface water, groundwater and groundwater remediation;
•Analysis of the interfaces between sediments and water, and between water and atmosphere, focusing specifically on anthropogenic impacts;
•Mathematical modelling, systems analysis, machine learning, and beneficial use of big data related to the anthropogenic water cycle;
•Socio-economic, policy, and regulations studies.