Indigenous Iron-Reducing Bacteria and Their Impacts on Arsenic Release in Arsenic-Affected Aquifer in Jianghan Plain
Gao Jie
Zheng Tianliang
Deng Yamin
Jiang Hongchen
Abstract：Microbial mediated iron-oxide mineral reduction and subsequent arsenic mobilization is the primary cause of arsenicrich groundwater in south and southeastern Asia,however,the role of iron-reducing and arsenic-reducing microbes isolated from aquifer is not clearly understood.In this study,four strains,Citrobacter sp.JH-1,Clostridium sp.JH-6,Exiguobacterium sp.JH-13 and Paenibacillus sp.JH-33,were isolated from the aquifer in Jianghan plain,which is the typical arsenic-rich aquifer in central China.Each of them was used to identify their ability of arsenate (As(Ⅴ)),ferric iron (Fe(Ⅲ)) and ferrihydrite reduction by batch cultural experiment under aerobic and anaerobic condition.The results indicate that all these four strains can reduce both As(Ⅴ) and Fe(Ⅲ) under anaerobic condition.Among them,the Citrobacter sp.JH-1 possessed the strongest reducing ability for As(Ⅴ),which could reduce 2.22μmol/L As(Ⅴ) after 96 h,and it could also reduce amorphous iron oxide minerals (ferrihydrite) under aerobic condition.After the cultivation with the sediment sample collected from in situ aquifer,Citrobacter sp.JH-1 could release 510 mg/kg iron and 1 150 μg/kg arsenic into groundwater.These results could provide direct evidence and insights for the cause of arsenic-rich groundwater in Jianghan plain.
Keywords：Jianghan plainfunction microorganismarsenic reductioniron reductionarsenic releasebiogeochemistryhydrogeology
Publication Date：2017-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：11( 716-726 )