State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, School of Resource and Environmental Engineering, East China University of Science and Technology, Shanghai, 200237, China.
State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, School of Resource and Environmental Engineering, East China University of Science and Technology, Shanghai, 200237, China; Ningbo Yonghuanyuan Environmental Engineering and Technology Co., Ltd, China.
Chemosphere. 2023 Nov;341:140008. doi: 10.1016/j.chemosphere.2023.140008. Epub 2023 Sep 2.
Nickel (Ni), as one of the essential micronutrients, exists widely in nature, but high concentration of Ni in soil can pose certain biological toxicity. Nano zero-valent iron (nZVI) and rhamnolipid modified nZVI (RL@nZVI) can effectively stabilize Ni in soil. In this study, the stabilization effect of nZVI and RL@nZVI on the Ni-polluted soil under simulated acid rain and the microbial community response during the soil remediation under different Ni levels (200, 600, and 1800 mg/kg) were investigated. The results show that the addition of nZVI and RL@nZVI increased the pH of leachate to neutral and decreased the amount of Ni in leachate (23.33%-47.06% by nZVI and 50.01%-70.47% by RL@nZVI), indicating that nZVI and RL@nZVI could reduce the potential radial migration risk of Ni in soil under simulated acid rain. The addition of RL@nZVI was beneficial to recover the soil bacterial community diversity, which was inhibited by Ni pollution, and rhamnolipid coating could reduce the toxicity of nZVI. The dominant bacteria in RL@nZVI-treated soil with low, medium, and high Ni pollution were Firmicutes, Proteobacteria and Actinobacteria, respectively. Soil potential, total organic carbon, and pH were the main driving factors affecting the bacterial community structure, while Ni stress only caused changes in the relative abundance of some tolerant bacteria.
镍（Ni）作为一种必需的微量元素，广泛存在于自然界中，但土壤中高浓度的镍可能具有一定的生物毒性。纳米零价铁（nZVI）和鼠李糖脂修饰的 nZVI（RL@nZVI）可以有效地稳定土壤中的镍。本研究考察了 nZVI 和 RL@nZVI 对模拟酸雨条件下镍污染土壤的稳定效果，以及在不同镍水平（200、600 和 1800mg/kg）下土壤修复过程中微生物群落的响应。结果表明，nZVI 和 RL@nZVI 的添加将浸出液的 pH 值提高至中性，并降低了浸出液中的镍含量（nZVI 降低了 23.33%-47.06%，RL@nZVI 降低了 50.01%-70.47%），表明 nZVI 和 RL@nZVI 可以降低模拟酸雨条件下土壤中镍的潜在径向迁移风险。RL@nZVI 的添加有利于恢复因镍污染而受到抑制的土壤细菌群落多样性，并且鼠李糖脂的涂层可以降低 nZVI 的毒性。在低、中、高镍污染的 RL@nZVI 处理土壤中，优势细菌分别为厚壁菌门、变形菌门和放线菌门。土壤潜在性、总有机碳和 pH 是影响细菌群落结构的主要驱动因素，而镍胁迫仅导致一些耐受细菌的相对丰度发生变化。
