Contribution of redox-active properties of compost-derived humic substances in hematite bioreduction  

作　　者：Chao Yang Lin-Xiao Hou Bei-Dou Xi Li-An Hou Xiao-Song He 

机构地区：[1]State Key Laboratory of Environmental Criteria and Risk Assessment,Chinese Research Academy of Environmental Sciences,Beijing 100012,China [2]State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution,Chinese Research Academy of Environmental Sciences,Beijing 100012,China [3]School of Environmental Science and Engineering,Tianjin University,Tianjin 300350,China [4]College of Chemical and Biological Engineering,Zhejiang University,Hangzhou 310027,China [5]High-Tech Institute of Beijing,Beijing 710025,China

出　　处：《Chinese Chemical Letters》2022年第5期2731-2735,共5页中国化学快报（英文版）

基　　金：supported by Central Research Institutes of Basic Research and Public Service Special Operations of Chinese Research Academy of Environmental Sciences(No.2019YSKY-023).

摘　　要：The compost-derived humic substances(HS)can function as electron mediators for promoting hematite bioreduction because of its redox capacity.Humification process can affect redox capacities of compost-derived HS by changing its intrinsic structure.However,the redox properties of compost-derived HS link-ing with hematite bioreduction during composting still remain unclear.Herein,we investigated the redox capacities of compost-derived HS,and assessed the responses of the redox capacities to the hematite bioreduction.The result showed that compost-derived HS(i.e.,humic acids(HA)and fulvic acids(FA))were able to accept electrons from Shewanella oneidensis MR-1,and the electron accepting capacity was increased during composting.Furthermore,it could be functioned as electron mediators for promoting the hematite bioreduction,achieving 1.19-2.15 times compared with the control experience.Not only the aromatic structures(quinone)but also the non-quinone structures such as nitrogen-and sulfur-containing functional moieties were served as the redox-active functional groups of compost-derived HS.Our work proved that the aromatic functional groups and the heteroatom structures(especially N)were important to the hematite bioreduction.This study highlights the redox-active properties of compost-derived HS and its impact on the microbial reduction of iron mineral.Redox capacity of compost-derived HS might mitigate the environmental risk of contaminants when the composting production was added into the contaminated soils as low-cost repair materials.

关 键 词：COMPOSTING Humic substances Reducing capacities Humic acids Hematite bioreduction 

分 类 号：TF55[冶金工程—钢铁冶金]