School of Water Resources and Environment, Key Laboratory of Groundwater Circulation and Environmental Evolution (China University of Geosciences Beijing), Ministry of Education, Beijing 100083, China.
School of Water Resources and Environment, Key Laboratory of Groundwater Circulation and Environmental Evolution (China University of Geosciences Beijing), Ministry of Education, Beijing 100083, China.
Sci Total Environ. 2021 May 10;768:145331. doi: 10.1016/j.scitotenv.2021.145331. Epub 2021 Jan 22.
Selenate [Se(VI)] with higher content in groundwater will be harmful for human beings. Hence, effective treatment for Se(VI) in aquifer should be conducted reasonably. Microbial reduction of Se(VI) to elemental selenium with weak movability and toxicity has attracted significant attention due to its high efficiency and no secondary contamination. However, hydrodynamic and hydrochemical influences with corresponding mechanisms during Se(VI) bioreduction are still not clear. In this study, influences of flow rate, initial Se(VI) and organic concentrations, coexisting nitrate were evaluated. Se(VI) removal efficiency and capacity reached 96.42 ± 6.82% and 41.28 ± 3.41 (g/m·d) with flow rate of 0.56 mL/min, initial Se(VI) and chemical organic demand concentrations of 10 mg/L and 400 mg/L. Dechloromonas and Pseudomonas were presumably contributed to Se(VI) reduction, with upregulated serA and tatC genes. Solid Se was identified as the final product from Se(VI) reduction. These results will be beneficial for the further comprehending of Se(VI) remediation in aquifer.
地下水中硒酸盐（Se(VI)）含量过高会对人类健康造成危害。因此，需要合理地对含水层中的 Se(VI)进行有效处理。微生物将 Se(VI)还原为元素硒，其迁移性和毒性较弱，具有高效、无二次污染等优点，因此受到了广泛关注。然而，其在 Se(VI)生物还原过程中的水动力和水化学影响及其相应机制仍不清楚。本研究评估了流速、初始 Se(VI)和有机浓度、共存硝酸盐的影响。当流速为 0.56mL/min、初始 Se(VI)和化学需氧量浓度分别为 10mg/L 和 400mg/L 时，Se(VI)去除效率和容量分别达到 96.42±6.82%和 41.28±3.41 (g/m·d)。推测 Dechloromonas 和 Pseudomonas 参与了 Se(VI)的还原，serA 和 tatC 基因被上调。从 Se(VI)还原中鉴定出最终产物为固态硒。这些结果有助于进一步了解含水层中 Se(VI)的修复。
