Controlling microbial arsenite oxidation and mobilization in arsenite-adsorbed iron minerals: The Influence of pH conditions and mineralogical composition

文献类型： 外文期刊

第一作者： Cai, Xiaolin

作者： Cai, Xiaolin;Zhang, Zhennan;Yin, Naiyi;Du, Huili;Yang, Mei;Cui, Liwei;Cui, Yanshan;Cai, Xiaolin;Zhang, Zhennan;Yin, Naiyi;Du, Huili;Yang, Mei;Cui, Liwei;Cui, Yanshan;Lu, Wenyi;Chen, Shibao

作者机构：

关键词： Arsenic biogeochemical cycling; As(III)-oxidizing bacteria; X-ray absorption spectroscopy; Bacterial adhesion; Soil remediation

期刊名称：JOURNAL OF HAZARDOUS MATERIALS （ 影响因子：14.224； 五年影响因子：12.984 ）

ISSN： 0304-3894

年卷期： 2022 年 433 卷

页码：

收录情况： SCI

摘要： The oxidation of aqueous arsenite (As(III)) by As(III)-oxidizing bacteria is known to attenuate the mobilization and toxicity of arsenic, and is regarded as potential method for As(III)-pollution remediation. However, during the interactions between As(III)-oxidizing bacteria and different As(III)-adsorbed soil Fe-minerals, the oxidation and partitioning of solid-phase As(III), as well as the controlling mechanisms, remain unclear. In this study, we therefore incubated three As(III)-adsorbed Fe-minerals with a typical As(III)-oxidizing bacteria (Pseudomonas sp. HN-1) at different pH conditions. After microbial oxidation, the percentage of arsenate (As(V)) was significantly higher at pH 7 (15-94%) and 9 (12-89%) than at pH 4 (6-50%) in all Fe-minerals. Incubation of As(III)-oxidizing bacteria promoted As-immobilization under acidic-conditions but As-mobilization under alkaline-conditions. Arsenic-X-ray adsorption spectroscopy results showed that solid-phase As(V) fraction in goethite, hematite and magnetite was 27-64%, 5-12% and 50-91%, respectively. Compared with the corner-sharing As(III)-adsorption complexes formed on magnetite, the edge-sharing complexes on hematite were significantly more stable towards microbial-oxidation. Additionally, the strong adhesion between strain HN-1 and hematite probably limit bacterial-activity and mobility, thereby inhibiting microbial As(III)-oxidation. Our findings elucidate the controlling mechanisms of microbial As(III)-oxidation in different As(III)-adsorbed Fe-minerals and demonstrate strain HN-1 is an excellent candidate for As(III)-remediation in soils containing goethite and magnetite.

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