title: Heterogeneity of the electron exchange capacity of kitchen waste compost-derived humic acids based on fluorescence components.
abstract: Composting is widely used for recycling of kitchen waste to improve soil properties, which is mainly attributed to the nutrient and structural functions of compost-derived humic acids (HAs). However, the redox properties of compost-derived HAs are not fully explored. Here, a unique framework is employed to investigate the electron exchange capacity (EEC) of HAs during kitchen waste composting. Most components of compost-derived HAs hold EEC, but nearly two-thirds of them are found to be easily destroyed by Shewanella oneidensis MR-1 and thus result in an EEC lower than the electron - donating capacity in compost-derived HAs. Fortunately, a refractory component also existed within compost-derived HAs and could serve as a stable and effective electron shuttle to promote the MR-1 involved in Fe(III) reduction, and its EEC was significantly correlated with the aromaticity and the amount of quinones. Nevertheless, with the increase of composting time, the EEC of the refractory component did not show an increasing trend. These results implied that there was an optimal composting time to maximize the production of HAs with more refractory and redox molecules. Recognition of the heterogeneity of EEC of the compost-derived HAs enables an efficient utilization of the composts for a variety of environmental applications. Graphical abstract Microbial reduction of compost-derived HAs.
authors: College of Water Sciences, Beijing Normal University, Beijing, 100875, China.|State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, 8 Dayangfang, Beiyuan Road, Chaoyang District, Beijing, 100012, China.|State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution, Chinese Research Academy of Environmental Sciences, 8 Dayangfang, Beiyuan Road, Chaoyang District, Beijing, 100012, China.
authors: Ying
authors: Y
authors: Yuan
authors: State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, 8 Dayangfang, Beiyuan Road, Chaoyang District, Beijing, 100012, China.|State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution, Chinese Research Academy of Environmental Sciences, 8 Dayangfang, Beiyuan Road, Chaoyang District, Beijing, 100012, China.
authors: Wen-Bing
authors: WB
authors: Tan
authors: State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, 8 Dayangfang, Beiyuan Road, Chaoyang District, Beijing, 100012, China. hexs82@126.com.|State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution, Chinese Research Academy of Environmental Sciences, 8 Dayangfang, Beiyuan Road, Chaoyang District, Beijing, 100012, China. hexs82@126.com.
authors: Xiao-Song
authors: XS
authors: He
authors: College of Water Sciences, Beijing Normal University, Beijing, 100875, China. xibeidou@263.net.|State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, 8 Dayangfang, Beiyuan Road, Chaoyang District, Beijing, 100012, China. xibeidou@263.net.|State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution, Chinese Research Academy of Environmental Sciences, 8 Dayangfang, Beiyuan Road, Chaoyang District, Beijing, 100012, China. xibeidou@263.net.
authors: Bei-Dou
authors: BD
authors: Xi
authors: State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, 8 Dayangfang, Beiyuan Road, Chaoyang District, Beijing, 100012, China.|State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution, Chinese Research Academy of Environmental Sciences, 8 Dayangfang, Beiyuan Road, Chaoyang District, Beijing, 100012, China.
authors: Ru-Tai
authors: RT
authors: Gao
authors: State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, 8 Dayangfang, Beiyuan Road, Chaoyang District, Beijing, 100012, China.|State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution, Chinese Research Academy of Environmental Sciences, 8 Dayangfang, Beiyuan Road, Chaoyang District, Beijing, 100012, China.
authors: Hui
authors: H
authors: Zhang
authors: State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, 8 Dayangfang, Beiyuan Road, Chaoyang District, Beijing, 100012, China.|State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution, Chinese Research Academy of Environmental Sciences, 8 Dayangfang, Beiyuan Road, Chaoyang District, Beijing, 100012, China.
authors: Qiu-Ling
authors: QL
authors: Dang
authors: State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, 8 Dayangfang, Beiyuan Road, Chaoyang District, Beijing, 100012, China.|State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution, Chinese Research Academy of Environmental Sciences, 8 Dayangfang, Beiyuan Road, Chaoyang District, Beijing, 100012, China.
authors: Dan
authors: D
authors: Li
mesh_terms: D001673:Biodegradation, Environmental; D000076282:Composting; D004583:Electrons; D005502:Food; D006801:Humans; D006812:Humic Substances / Q000032:analysis*; D007501:Iron / Q000737:chemistry; D010084:Oxidation-Reduction; D020592:Shewanella / Q000378:metabolism*; D013053:Spectrophotometry / Q000379:methods; D013997:Time Factors; D014866:Waste Products / Q000032:analysis
chemical_list: D006812:Humic Substances; D014866:Waste Products; D007501:Iron
keywords: Composting; Electron exchange capacity; Humic acid; Microbial reduction