Fei Yangmei, Zhang Baogang, He Jinxi, Chen Cuibai, Liu Hui
School of Water Resources and Environment, MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences (Beijing), Beijing 100083, PR China.
School of Water Resources and Environment, MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences (Beijing), Beijing 100083, PR China.
J Hazard Mater. 2022 Feb 15;424(Pt C):127608. doi: 10.1016/j.jhazmat.2021.127608. Epub 2021 Oct 27.
Severe vanadium pollution in deep soil through surface infiltration during mining activities has been particularly concerned, but little is known about vanadium migration dynamics in vertical soil profile. Indigenous microorganisms widely exist in soil, however, their functions and suffered impacts during vertical vanadium migration have rarely been investigated. In this study, 100 cm height columns were constructed with undisturbed soil around vanadium tailing reservoir were constructed to describe vertical vanadium transport process and corresponding interactions between vanadium and indigenous microorganisms. 91 d continuous leaching with pentavalent vanadium [V(V)] showed that V(V) gradually downward migrated. Soil microorganisms slowed down vertical V(V) migration rate by transferring V(V) to insoluble tetravalent vanadium. Enriched Gemmatimonadaceae and Actinobacteria were identified to contribute to microbial V(V) transformation. Co-existing nitrate weakened the soil's ability to intercept V(V) via electron competition. Microbial communities were reshaped by vanadium during leaching, while enzyme activities increased slightly due to vanadium stimulation. This work advances the understanding of vertical vanadium migration characteristics in soil, which is essential to risk management and effective remediation of vanadium-polluted sites.
采矿活动期间通过地表渗透造成的深层土壤中严重的钒污染一直备受关注，但关于钒在土壤垂直剖面中的迁移动态却知之甚少。土壤中广泛存在着本土微生物，然而，它们在钒垂直迁移过程中的功能及受到的影响却鲜有研究。在本研究中，利用钒尾矿库周边的原状土构建了100厘米高的土柱，以描述钒的垂直迁移过程以及钒与本土微生物之间的相应相互作用。用五价钒[V(V)]进行91天的连续淋溶试验表明，V(V)逐渐向下迁移。土壤微生物通过将V(V)转化为不溶性的四价钒减缓了V(V)的垂直迁移速率。已鉴定出富集的芽单胞菌科和放线菌科有助于微生物对V(V)的转化。共存的硝酸盐通过电子竞争削弱了土壤截留V(V)的能力。淋溶过程中钒重塑了微生物群落，而酶活性因钒的刺激略有增加。这项工作增进了对土壤中钒垂直迁移特征的理解，这对于钒污染场地的风险管理和有效修复至关重要。
