Bioreduction of hexavalent chromium:Effect of compost-derived humic acids and hematite  

作　　者：Chao Yang Ming-Xia Zheng Yuan Zhang Bei-Dou Xi Zai-Feng Tian Xiao-Song He 

机构地区：[1]School of Environmental Science and Engineering,Tianjin University,Tianjin 300350,China [2]State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution,Chinese Research Academy of Environmental Sciences,Beijing 100012,China [3]State Key Laboratory of Environmental Criteria and Risk Assessment,Chinese Research Academy of Environmental Sciences,Beijing 100012,China [4]Hebei Engineering Research Center for Geographic Information Application,Institute of Geographical Sciences,Hebei Academy of Sciences,Shijiazhuang 050030,China [5]Hebei Provincial Academy of Ecological and Environmental Science,Shijiazhuang 050037,China

出　　处：《Chinese Chemical Letters》2020年第10期2693-2697,共5页中国化学快报（英文版）

基　　金：the National Key Research and Development Program of China(No.2018YFC1800703);the National Water Pollution Control and Management Technology Major Project of China(No.2018ZX07110006)。

摘　　要：Composting can enhance the nutrie nt ele ments cycling and reduce carbon dioxide production.However,little information is available regarding the application of compost for the remediation of the contaminated soil.In this study,we assess the response of the redox capacities(electron accepting capacities(EAC)and electron donating capacities(EDC))of compost-derived humic acids(HAs)to the bioreduction of hexavalent chromium(Cr(Ⅵ)),especially in presence of hematite.The result showed that the compost-derived HAs played an important role in the bioreduction of Cr(Ⅵ)in presence and absence of hematite under the anoxic,neutral(pH 7)and motionless conditions.Based on the pseudo-first order kinetic model,the rate constants of Cr(Ⅵ)reduction increased by 1.36-2.0 times when compost-derived HAs was added.The redox capacity originating from the polysaccharide structure of compost-derived HAs made them effective in the direct Cr(Ⅵ)reduction(without MR-1)at pH 7.Meanwhile,the reduction rates were inversely proportional to the composting treatment time.When iron mineral(Fe_(2)O_(3))and compost-derived HAs were both present,the rate constants of Cr(Ⅵ)reduction increased by 2.35-5.09,which were higher than the rate of Cr(Ⅵ)reduction in HA-only systems,indicating that the hematite played a crucial role in the bioreduction process of Cr(Ⅵ).EAC and quinonoid structures played a major role in enhancing the bioreduction of Cr(Ⅵ)when iron mineral and compost-derived HAs coexisted in the system.The results can extend the application fields of compost and will provide a new insight for the remediation of Cr(Ⅵ)-contaminated soil.

关 键 词：BIOREDUCTION Hexavalent chromium COMPOSTING Humic acids HEMATITE 

分 类 号：X53[环境科学与工程—环境工程]