摘要
石门雄黄矿区土壤长期受到砷的严重污染,但当地常住居民仍然利用砷污染土壤种植水稻等农作物,地球化学分析显示该地区尾矿土壤中存在大量硫酸盐和不可溶性砷。为研究硫酸盐对微生物催化的尾矿土壤中砷溶解与释放过程的影响,采集了湖南石门雄黄矿区的尾矿土壤样品进行了模拟试验,利用厌氧操作技术、分子生物技术等探讨了硫酸盐如何影响微生物介导的尾矿土壤中砷的溶解与释放。石门雄黄矿区的尾矿土壤中存在能够利用乳酸盐作为唯一的电子供体,将不可溶性As(Ⅴ)转化为可溶性As(Ⅲ)的具有显著砷酸盐呼吸活性的呼吸性砷还原菌(DARPs);微生物群落结构分析显示,尾矿土壤微生物群落中存在多种DARP,它们在厌氧条件下促进了尾矿土壤中砷和铁的溶解与释放。值得注意的是,当向尾矿土壤中添加硫酸盐时,微生物催化的砷和铁的溶解与释放显著增加,同时乳酸盐和硫酸盐的含量急剧下降。进一步研究发现,硫酸盐显著增强了尾矿土壤中呼吸性砷还原酶基因的丰度,这表明人类活动中硫酸盐的使用会使当地土壤砷污染加剧。
Though the soil in the Shimen Realgar Mine area has been heavily polluted by arsenic for a long time,local residents still use arsenic-contaminated soil to grow crops such as rice.Geochemical analysis shows there are large amounts of sulfate and insoluble arsenic in the soils there.In order to study the effect of sulphate on the microbial-catalyzed dissolution and the release of arsenic in the soil of the mine,this paper collects arsenic-rich soil samples from Shimen Realgar Mine in Hunan Province of China for simulation experiments,and uses anaerobic operation technique,molecular biological technique to discuss the influence of sulfate on the dissolution and release of arsenic in tailings soil catalyzed by microorganism.The results indicate that there are arsenate-respiring prokaryotes(DARPs)in the tailings soils of Shimen Realgar Mine area,which have significant arsenate-respiring activities by using lactate as the sole electron donor to transform the insoluble As(Ⅴ)to soluble As(Ⅲ).Community structure analysis shows that there are diversely dissimilatory DARPs in the indigenous microbial communities of the soils.They efficiently promotes the dissolution and release of arsenic and iron from soils under anaerobic condition.Obviously,when sulfate is amended into the microcosms,the microbial-catalyzed dissolution and release of arsenic and iron are significantly increased,while the contents of lactate and sulphate are drastically decreased.Further study shows that sulfate significantly enhances the arsenate-respiring reductase gene abundances in the soils,which suggests that the use of sulphate in human activities can exacerbate local arsenic contamination.
作者
吴薇薇
陈晓明
曾宪春
WU Weiwei;CHEN Xiaoming;ZENG Xianchun(School of Environmental Studies,China University of Geosciences (Wuhan),Wuhan 430074,China)
出处
《安全与环境工程》
CAS
北大核心
2020年第3期48-53,89,共7页
Safety and Environmental Engineering
基金
国家自然科学基金项目(41272257)。
作者简介
吴薇薇(1993—),女,硕士研究生,主要研究方向为地质微生物学,E-mail:wuweiweicug@163.com。
