| 砷氧化菌对胡敏酸络合As (Ⅲ)的氧化作用 |
| 摘要点击 1371 全文点击 482 投稿时间：2018-03-04 修订日期：2018-03-27 |
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| 中文关键词 砷 胡敏酸 砷氧化菌 砷氧化 X射线吸收近边结构光谱(XANES) |
| 英文关键词 arsenic humic acid arsenic oxide bacteria oxidation of arsenic X-ray absorption near edge structure (XANES) |
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| 中文摘要 |
| 土壤砷与土壤微生物相互作用是土壤砷形态转化中需要重点关注的内容之一.为了研究砷氧化菌对胡敏酸络合三价砷[HA-As（Ⅲ）]的作用，设置了不同pH值反应体系，研究砷氧化菌HN-2对HA-As（Ⅲ）作用下，砷的形态变化及其在固液两相中的分配.结果表明，在HA与As（Ⅲ）络合过程中，HA可以将一部分游离态As（Ⅲ）氧化为As（Ⅴ）.其中，在pH=7的体系中，As（Ⅲ）被HN-2和HA氧化成As（Ⅴ）的效率最高.在含有砷氧化菌株和不含砷氧化菌株的体系中，0~10 h振荡过程中，HA-As材料均可以释放一部分As（Ⅲ）及As（Ⅴ）进入液相中，同时砷氧化菌可以快速地将As（Ⅲ）氧化为As（Ⅴ），而胡敏酸可以较缓慢地将As（Ⅲ）氧化为As（Ⅴ）；反应10~24 h期间，HN-2砷氧化菌可以将络合态HA-As（Ⅲ）转化为游离态As（Ⅲ）并氧化为As（Ⅴ）；48 h后反应逐渐达到平衡.固相同步辐射结果可以进一步证明HN-2砷氧化菌对络合态As（Ⅲ）的释放及氧化作用. |
| 英文摘要 |
| The interaction between soil arsenic and soil microorganisms has been identified as one of the important parts of the morphological transformation of soil arsenic. In order to investigate the interaction between Humic Acid complexing As(Ⅲ)[HA-As(Ⅲ)] and As(Ⅲ)-oxidizing bacteria (HN-2), the changes in arsenic speciation in the liquid phase and the solid phase, with different pH, were studied. The results indicated there was better As(Ⅲ) oxidation efficiency in the pH 7 reaction system. A part of As(Ⅲ) would be discharged from the HA-As(Ⅲ) solid phase during hours 0-10 in the reaction system, with or without HN-2, and meanwhile it was found that HN-2 oxidized As(Ⅲ) to As(Ⅴ) rapidly, while As(Ⅲ) was oxidized into As(Ⅴ) by HA gradually. As(Ⅲ) complexing HA can be transformed into free-As(Ⅲ), and then oxidized into free-As(Ⅴ) by HN-2 over hours 10-24 of the reaction. The system achieved the equilibrium state after 48 h. The results of the X-ray absorption near edge structure (XANES) further confirmed the conclusions above. |
