Iron redox cycling drives enhanced methanogenesis in magnetic biochar-mediated anaerobic digestion of waste-activated sludgeOA
Anaerobic digestion provides an essential pathway for reducing organic waste while simultaneously recovering bioenergy.To enhance this process,magnetic biochars are frequently employed as conductive additives to promote direct interspecies electron transfer(DIET)among syntrophic microorganisms.However,the fundamental mechanisms regarding how iron species leached from these materials influenceiron transformation and electron fluxremain poorly understood.Here we show that the leaching of iron species from magnetic biochar establishes a stable Fe(III)/Fe(II)redox cycle that accelerates the hydrolysis,acidogenesis,and methanogenesis of waste-activated sludge.We findthat cumulative methane production increases by 17%as leached Fe(III)facilitates dissimilatory iron reduction,followed by secondary mineralization into high-crystalline iron species.This process selectively enriches electroactive taxa,including Geobacter and Methanothrix,and transitioned the dominant electron transfer mechanism from cytochrome c-dependent pathways to a Fe(III)/Fe(II)redox-driven DIET.These mechanisms advance our understanding of conductive material-mediated AD,offering strategies to optimize energy recovery from waste-activated sludge and support sustainable sludge management in wastewater treatment.
Qing-Bin Meng;Zhang-Wei He;Zhi-Hua Li;Cong-Cong Tang;Ai-Juan Zhou;Bin Liang;Wenzong Liu;Yong-Xiang Ren;Aijie Wang
Key Laboratory of Northwest Water Resource,Environment and Ecology,Ministry of Education,School of Environmental and Municipal Engineering,Xi''an University of Architecture and Technology,Xi''an,710055,China Shaanxi Key Laboratory of Environmental Engineering,Xi''an University of Architecture and Technology,Xi''an,710055,ChinaKey Laboratory of Northwest Water Resource,Environment and Ecology,Ministry of Education,School of Environmental and Municipal Engineering,Xi''an University of Architecture and Technology,Xi''an,710055,China Shaanxi Key Laboratory of Environmental Engineering,Xi''an University of Architecture and Technology,Xi''an,710055,ChinaKey Laboratory of Northwest Water Resource,Environment and Ecology,Ministry of Education,School of Environmental and Municipal Engineering,Xi''an University of Architecture and Technology,Xi''an,710055,China Shaanxi Key Laboratory of Environmental Engineering,Xi''an University of Architecture and Technology,Xi''an,710055,ChinaKey Laboratory of Northwest Water Resource,Environment and Ecology,Ministry of Education,School of Environmental and Municipal Engineering,Xi''an University of Architecture and Technology,Xi''an,710055,China Shaanxi Key Laboratory of Environmental Engineering,Xi''an University of Architecture and Technology,Xi''an,710055,ChinaDepartment of Water Supply and Drainage,Taiyuan University of Technology,Taiyuan,030024,ChinaState Key Laboratory of Urban-rural Water Resource and Environment,School of Eco-Environment,Harbin Institute of Technology,Shenzhen,518055,ChinaState Key Laboratory of Urban-rural Water Resource and Environment,School of Eco-Environment,Harbin Institute of Technology,Shenzhen,518055,ChinaKey Laboratory of Northwest Water Resource,Environment and Ecology,Ministry of Education,School of Environmental and Municipal Engineering,Xi''an University of Architecture and Technology,Xi''an,710055,China Shaanxi Key Laboratory of Environmental Engineering,Xi''an University of Architecture and Technology,Xi''an,710055,ChinaState Key Laboratory of Urban-rural Water Resource and Environment,School of Eco-Environment,Harbin Institute of Technology,Shenzhen,518055,China
资源环境
Anaerobic digestionWaste-activated sludgeMagnetic biocharIron species leaching behaviorFe(III)/Fe(II)redox cycle
《Environmental Science and Ecotechnology》 2026 (1)
P.82-96,15
supported by the National Natural Science Foundation of China(No.52270139)the State Key Laboratory of Urban-rural Water Resource and Environment(Grant No.HC202459).
评论