本powerpoint演示文稿首先简要概述了砷（AS）和硝酸盐污染的来源。砷去除的可能机制 介绍了还原环境下的反应器系统流程图，以及预期的生物介导的反应器系统流程图 反应，并优化空床接触时间。

This powerpoint presentation begins by providing a brief overview of the sources of arsenic (AS) and nitrate contamination. Possible mechanisms of As removal under reducing environments are presented, along with a flow diagram of the reactor system, expected biologically-mediated reactions, and optimization of empty bed contact time.