Insights into selenate removal mechanism of hydrogen-based membrane biofilm reactor for nitrate-polluted groundwater treatment based on anaerobic biofilm analysis
Insights into selenate removal mechanism of hydrogen-based membrane biofilm reactor for nitrate-polluted groundwater treatment based on anaerobic biofilm analysis
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基于厌氧生物膜分析探讨氢基膜生物膜反应器处理硝酸盐污染地下水硒酸盐去除机理
DOI：
10.1016/j.ecoenv.2019.04.005
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发表时间：
2019
影响因子：
6.8
通讯作者：
Zhou Lijie
中科院分区：
文献类型：
--
作者：
Xia Siqing;Xu Xiaoyin;Zhou Lijie
基于厌氧生物膜分析，研究了氢基膜生物膜反应器（MBfR）处理硝酸盐污染地下水的硒酸盐去除机理。实验室规模的 MBfR 运行了 60 多天，包括电子平衡、结构分析和细菌群落鉴定。结果表明，厌氧生物膜对硒酸盐（95%）和硝酸盐（100%）具有出色的去除效果。氢气还原硒酸盐→亚硒酸盐→Se0是厌氧生物膜去除硒酸盐的主要途径，无定形Se0沉淀在生物膜中积累。观察到元素硒沿着横截面薄生物膜均匀分布。部分硒酸盐（3%）也被异养细菌还原成甲基硒化物。此外，β-变形菌门中的噬氢菌能够同时去除硝酸盐和硒酸盐，是生物膜中的优势菌种（超过85%），有助于稳定去除硝酸盐和硒酸盐。随着硒酸盐的输入，厌氧生物膜群落中也产生了具有去除硒酸盐和硝酸盐能力的细菌。
The selenate removal mechanism of hydrogen-based membrane biofilm reactor (MBfR) for nitrate-polluted groundwater treatment was studied based on anaerobic biofilm analysis. A laboratory-scale MBfR was operated for over 60 days with electron balance, structural analysis, and bacterial community identification. Results showed that anaerobic biofilm had an excellent removal of both selenate (95%) and nitrate (100%). Reduction of Selenate → Selenite → Se0with hydrogen was the main pathway of anaerobic biofilm for selenate removal with amorphous Se0precipitate accumulating in the biofilm. The element selenium was observed to be evenly distributed along the cross-sectional thin biofilm. A part of selenate (3%) was also reduced into methyl-selenide by heterotrophic bacteria. Additionally,Hydrogenophagabacteria ofβ-Proteobacteria, capable of both nitrate and selenate removal, worked as the dominant species (over 85%) in the biofilm and contributed to the stable removal of both nitrate and selenate. With the selenate input, bacteria with a capacity for both selenate and nitrate removal were also developed in the anaerobic biofilm community.