摘要
硫酸盐还原菌是厌氧环境中参与砷形态转化的重要微生物种群,其介导的生物地球化学循环过程对铁氧化物表面吸附态砷迁移转化的影响亟待深入研究.选取江汉平原典型高砷含水层原位沉积物分离纯化出一株严格厌氧硫酸盐还原菌Desulfovibrio JH-S1,对其进行砷和铁还原能力鉴定,并通过模拟培养实验探究硫酸盐还原菌参与下的铁矿物相转化对吸附态砷迁移的影响.Desulfovibrio JH-S1具有Fe(Ⅲ)还原能力,无硫和有硫体系中Fe(Ⅲ)均能被还原,但在硫酸盐充足条件下铁还原量显著增加;该菌株不具备As(Ⅴ)还原能力,但添加硫酸盐的培养体系中As(Ⅴ)去除率可达96%以上.Desulfovibrio JH-S1能够还原硫酸盐从而促进载砷的水铁矿还原转化为纤铁矿,并导致吸附的砷释放.江汉平原高砷含水层土著硫酸盐还原菌兼具硫酸盐/铁还原功能,参与了高砷含水层系统中砷-铁-硫耦合循环,对高砷地下水的形成具有重要作用.
Sulfate reducing bacteria(SRB)are important anaerobic microorganisms,which are actively involved in arsenic transformation.However,the effect of the biogeochemical cycle mediated by sulfate reducing bacteria on the migration and transformation of arsenic adsorbed on the surface of iron oxide is urgently needed to be further studied.In this study,a sulfate reducing bacterium,strain Desulfovibrio JH-1 was isolated from the aquifer sediments in typical arsenic affected region of Jianghan Plain.Its sulfate,arsenate and ferric iron reduction capacity was identified,and furtherly a microcosm experiment was carried out to determine its role on the mineral-phase transformation of As-bearing ferrihydrite and As mobilization.Results indicate that it possesses the capacity of iron reduction,Fe(Ⅲ)can be reduced regardless of the presence of sulfate in the system,the amount of iron reduction increases significantly under the sufficient sulfate environment.However,it doesn’t possess the capacity of arsenate reduction,the removal rate of As(Ⅴ)in the culture system with added sulfate could reach up to 96%.In addition,JH-S1 can promote the reduction and release of iron and arsenic from the As-bearing ferrihydrite by bacterially generated HS-,and promote the transformation of ferrihydrite to lepidocrocite.The present results provide new insights for the important role of indigenous sulfate reducing bacteria in the coupled Fe-S-As cycling in shallow aquifer system of the Jianghan Plain.
作者
徐雨潇
郑天亮
高杰
邓娅敏
蒋宏忱
Xu Yuxiao;Zheng Tianliang;Gao Jie;Deng Yamin;Jiang Hongchen(School of Environmental Studies,China University of Geosciences,Wuhan 430078,China;Geological Survey Institute,China University of Geosciences,Wuhan 430074,China;State Key Laboratory of Biogeology and Environmental Geology,China University of Geosciences,Wuhan 430078,China)
出处
《地球科学》
EI
CAS
CSCD
北大核心
2021年第2期652-660,共9页
Earth Science
基金
国家自然科学基金面上项目(Nos.41572226,41977174)
生物地质与环境地质国家重点实验室优先资助开放课题(No.128-GBL21711)。
关键词
硫酸盐还原菌
铁还原
砷
地下水
江汉平原
水文地质
sulfate reducing bacteria
iron reduction
arsenic
groundwater
Jianghan Plain
hydrogeology
