School of Water Resources and Environment, MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences (Beijing), Beijing 100083, P. R. China.
School of Water Resources and Environment, MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences (Beijing), Beijing 100083, P. R. China.
Water Res. 2020 Nov 1;186:116354. doi: 10.1016/j.watres.2020.116354. Epub 2020 Aug 28.
Vanadate [V(V)] and phenanthrene (PHE) commonly coexist in groundwater aquifer, posing potential threats to ecological environment and public health. However, little is known about the complicated biogeochemical processes involving microbial V(V) reduction coupled with co-metabolic PHE biodegradation. Herein we demonstrated that synchronous removal of V(V) and PHE could be realized under anaerobic condition. Complete V(V) removal and PHE degradation efficiency of 82.0 ± 0.8% were achieved in 7-d operation in batch experiment. 250-d continuous column experiment implied that hydrochemical condition affected V(V) and PHE removals. V(V) was reduced to insoluble vanadium (IV) and PHE was degraded into small molecule organics (e.g. salicylic acid). Geobacter and Acetobacterium used methanol and intermediates from PHE degradation as electron donors for V(V) reduction. PHE was decomposed by Mycobacterium and Clostridium with methanol as co-metabolic substrate and V(V) as electron acceptor. Genes encoding proteins for V(V) reduction (omcA, omcB and mtrC) and PHE degradation (phnAc) were upregulated. Cytochrome c and nicotinamide adenine dinucleotide promoted electron transfer for V(V) and PHE detoxification. Extracellular polymeric substances could bind V(V) and improve the bioavailability of PHE. Our findings provide a robust strategy for remediation of V(V) and PHE co-contaminated groundwater.
钒酸盐（V(V)）和菲（PHE）通常共存于地下水含水层中，对生态环境和公众健康构成潜在威胁。然而，对于涉及微生物 V(V)还原和共代谢 PHE 生物降解的复杂生物地球化学过程知之甚少。本研究表明，在厌氧条件下可以实现 V(V)和 PHE 的同步去除。在批式实验中，7 天的运行可实现完全去除 V(V)和 82.0±0.8%的 PHE 降解效率。250 天连续柱实验表明，水化学条件会影响 V(V)和 PHE 的去除。V(V)被还原为不溶性的钒（IV），PHE 被降解为小分子有机物（如水杨酸）。地杆菌和乙酸菌使用甲醇和 PHE 降解的中间产物作为 V(V)还原的电子供体。分枝杆菌和梭菌利用甲醇作为共代谢底物和 V(V)作为电子受体分解 PHE。编码 V(V)还原（omcA、omcB 和 mtrC）和 PHE 降解（phnAc）蛋白的基因被上调。细胞色素 c 和烟酰胺腺嘌呤二核苷酸促进了 V(V)和 PHE 解毒的电子转移。细胞外聚合物可以结合 V(V)并提高 PHE 的生物利用度。本研究结果为修复 V(V)和 PHE 共存的地下水提供了一种有效的策略。
