吸附态砷的氧化还原转化与释放机理

地下水体系中吸附态砷的价态转化及脱附释放过程与机制是砷生物地球化学研究中的关键科学问题。本项目将围绕吸附态砷的氧化还原转化为中心，以针铁矿、氧化钛、土壤沉积物为环境介质，发展以同步辐射为主的多种谱学技术原位研究固液微界面上砷的氧化还原反应动态过程；阐明吸附态砷在氧化还原转化及脱附释放中的关键过程及主控因子；重点研究微生物,尤其是砷、铁、硫还原菌群，在此过程中的作用与调控机制，探讨电子梭在砷还原菌参与下对吸附态砷的价态转化及释放的影响。有望在吸附态砷的还原脱附分子机制及基于微界面的微生物诱导调控原理等基础理论研究方面取得突破，为全面深入阐述砷的生物地球化学循环提供理论基础。

Redox transformation and release of the adsorbed arsenic into aquifer is the key scientific issue in arsenic biogeochemistry. This research will study the arsenic adsorbed on goethite, titanium oxide, and sediments. The research will develop multiple complementary characterization techniques including synchrotron-based methods to explore the redox reaction processes. The project will elucidate the key steps and controlling parameters during the arsenic redox reaction and release. The effects of microorganism, especially arsenic-, iron-, and sulfate-reducing bacteria, will be highlighted. The impact of electron shuttle in the presence of arsenic-reducing bacteria will be investigated. The research should shed light on the molecular-level mechanisms on the redox reactions and release of adsorbed arsenic. The results should provide the theoretical basis for further understanding of arsenic biogeochemical cycling.