砷耦合还原的微生物协同机制及其环境效应

Microorganism-mediated arsenic reduction and its environmental effects

摘要:

砷(arsenic, As)是一种常见的有毒污染元素，微生物介导的砷形态转变是砷生物地球化学循环的重要组成部分。在砷的各类微生物代谢过程中，砷的耦合还原对环境影响较大，也是容易被忽视的过程。本文主要从砷的生物地球化学循环出发，介绍了甲烷氧化、厌氧铵氧化、铁(Fe)-硫(S)氧化与砷耦合还原的微生物协同机制，有机质、pH值以及氧化还原电位是影响砷耦合还原的主要因素。砷经耦合还原后，毒性和迁移性大大增加，可能会增加砷污染的风险。因此，进一步明确碳(C)、氮(N)、Fe、S等这些元素在砷耦合过程中的影响以及挖掘出更多的微生物耦合还原过程，在防治砷污染方面具有重要意义。

关键词:砷;生物地球化学循环;耦合还原;微生物

Abstract:

Arsenic (As) is a common toxic pollution element. The microorganism-mediated transformation of arsenic forms is an important part in the biogeochemical cycle of As. In the various microbial metabolic processes involving As, the coupling reduction of As has a great impact on the environment and is a process that is easily overlooked. From the biogeochemical cycle of As, this review introduces the microorganism-mediated methane oxidation, anaerobic ammonium oxidation, and iron (Fe)-sulfur (S) oxidation coupled with As reduction. Organic matter, pH, and redox potential are the main factors affecting the coupling reduction. After the coupling reduction, the toxicity and migration of As are greatly enhanced, which may increase the risk of As pollution. Therefore, it is of great significance to clarify the influences of carbon, nitrogen, Fe, S and other elements on the coupling process and explore more microbial processes coupled with As reduction for the prevention and control of As pollution.

Key words:arsenic;biogeochemical cycle;coupling reduction;microorganism