微生物铁氧化作用对砷迁移转化的影响  

The effect of microbial iron oxidation on arsenic mobility and transformation

作　　者：王兆苏[1] 王新军[1] 陈学萍[1] 朱永官[1,2] 

机构地区：[1]中国科学院生态环境研究中心区域与城市生态国家重点实验室,北京100085 [2]中国科学院城市环境研究所城市环境与健康重点实验室,厦门361021

出　　处：《环境科学学报》2011年第2期328-333,共6页Acta Scientiae Circumstantiae

基　　金：国家自然科学基金项目(No. 41090282; 41090284)~~

摘　　要：采用厌氧培养的方法,从砷污染的水稻土中富集依赖硝酸盐的铁氧化菌群,通过监测培养体系中Fe和As的形态变化模拟水稻厌氧条件下微生物铁氧化过程对As迁移转化的影响.结果表明,约96%外源添加的Fe(Ⅱ)可在10d内氧化成Fe(Ⅲ),As(Ⅲ)对Fe(Ⅱ)的初期氧化速率具有一定的抑制作用;在微生物铁氧化过程中,As(Ⅲ)被氧化成As(V),并吸附在生成的铁氧化物表面或与其共沉淀.微生物的铁氧化过程可能降低了As的移动性,从而抑制水稻对砷的吸收,降低了砷污染对人体健康的风险.To observe the effect of the Fe（Ⅱ）-oxidizing process on As mobility and transformation,anaerobic nitrate-dependent Fe-oxidizing bacteria were enriched from an arsenic （As） polluted paddy soil. The Fe and As speciation and concentrations were monitored throughout an incubation experiment. The results showed that 96% Fe（Ⅱ） was oxidized in 10 days; and simultaneously,As（Ⅲ） was oxidized to As（V）,which was adsorbed or co-precipitated by the newly formed Fe（Ⅲ） oxide. The oxidizing rate of Fe（Ⅱ） was restrained by As（Ⅲ） at the initial stage. These results indicate that As mobility is potentially limited by microbial iron oxidation in the paddy soil,and subsequently As uptake by rice could be decreased.

关 键 词：硝酸盐 铁氧化菌 砷 水稻土 

分 类 号：X53[环境科学与工程—环境工程]