硫酸盐还原菌介导的砷/锑-硫耦合氧化还原转化研究

硫酸盐还原菌介导的砷/锑-硫耦合氧化还原转化是砷/锑生物地球化学研究中的前沿基础科学问题。硫代砷/锑酸盐的环境生成与转化是砷/锑生物地球化学循环中关键但易被忽视的环节，主要难点在于缺乏对不稳定的硫代砷/锑酸盐的定性定量检测方法体系。本项目将围绕硫代砷/锑酸盐的生成转化为中心，以溶解态、吸附态、砷/锑矿三种赋存形态的砷/锑为研究对象，发展以同步辐射为主的多种原位谱学技术，研究固液微界面上砷/锑-硫耦合的氧化还原动态反应过程；阐明砷/锑-硫耦合氧化还原反应机制及主控因子；探索厌氧-好氧交替过程中，砷氧化菌和砷还原菌对硫代砷/锑酸盐的迁移转化影响；结合实际环境样品分析结果，建立硫代砷/锑酸盐参与的砷/锑-硫耦合生物地球化学循环网络。有望在砷/锑-硫耦合氧化还原反应机制及硫代砷/锑酸盐在微生物作用下的迁移转化过程等前沿基础研究方面取得突破，为全面深入探索砷、锑的的生物地球化学循环提供理论基础。

The coupled redox transformation of arsenic/antimony-sulfur mediated by sulfate reducing bacterial (SRB) is fundamental in the biogeochemical cycling of arsenic/antimony. The environmental formation and transformation of thioarsenic/thioantimony are central but usually neglected because of the difficulty in identifying and quantifying the unstable thiolated arsenic and antimony species. This research will study the speciation of arsenic and antimony in dissolved and adsorbed phase, as well as arsenic/antimony sulfides. The research will develop multiple in-situ spectroscopic techniques including synchrotron-based methods to explore the redox reaction processes, along with chromatogramphy and mass spectrometry. The project will elucidate the key steps and controlling parameters during the arsenic/antimony-sulfur coupled redox transformation. The effects of arsenic-reducing and -oxidizing bacteria on thioarsenic/thioantimony will be investigated. Integrating the transformation process of arsenic and antimony in the natural environment, the study will establish arsenic/antimony-sulfur coupled biogeochemical cycles. The results should provide the theoretical basis for further understanding of arsenic/antimony biogeochemical cycling.