Roles of different active metal-reducing bacteria in arsenic release from arsenic-contaminated paddy soil amended with biochar

JOURNAL OF HAZARDOUS MATERIALS

卷:344

Article

Qiao, Jiang-tao^1,2,3  Li, Xiao-min²  Li, Fang-bai² 

[1] Chinese Acad Sci, Guangzhou Inst Geochem, Guangzhou 510640, Guangdong, Peoples R China

[2] Guangdong Inst Ecoenvironm Sci & Technol, Guangdong Key Lab Integrated Agroenvironm Pollut, Guangzhou 510650, Guangdong, Peoples R China

[3] Univ Chinese Acad Sci, Beijing 100049, Peoples R China

关键词: Biochar;    Arsenic reduction;    Metal-reducing bacteria;    Transcriptional activity;    Paddy soil;   

DOI  :  10.1016/j.jhazmat.2017.11.025

来源: Elsevier

【 摘 要 】

Although biochar has great potential for heavy metal removal from sediments or soils, its impact on arsenic biogeochemistry in contaminated paddy fields remains poorly characterized. In this study, anaerobic microcosms were established with arsenic-contaminated paddy soil to investigate arsenic transformation as well as the potentially active microbial community and their transcriptional activities in the presence of biochar. The results demonstrated that biochar can simultaneously stimulate microbial reduction of As(V) and Fe(III), releasing high levels of As(III) into the soil solution relative to the control. Total RNAs were extracted to profile the potentially active microbial communities, which suggested that biochar increased the abundance of arsenic- and iron-related bacteria, such as Geobacter, Anaeromyxobacter and Clostridium compared to the control. Reverse transcription, quantitative PCR (RT-qPCR) showed that the abundance of Geobacter transcripts were significantly stimulated by biochar throughout the incubation. Furthermore, significant positive correlations were observed between the abundance of Geobacter transcripts and As(V) concentrations, and between that of Clostridium transcripts and Fe(III) concentrations in biochar-amended microcosms. Our findings suggest that biochar can stimulate the activity of metal-reducing bacteria to promote arsenic mobility. The Geobacter may contribute to As(V) reduction in the presence of biochar, while Clostridium has a role in Fe(III) reduction. (C) 2017 Elsevier B.V. All rights reserved.

【 授权许可】

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