Jiang Jianguo, Yang Meng, Gao Yuchen, Wang Jiaming, Li Dean, Li Tianran
School of Environment, Tsinghua University, Beijing, 100084, China; Key Laboratory of Solid Waste Management and Environment Safety (Tsinghua University), Ministry of Education, Tsinghua University, Beijing, 100084, China; Collaborative Innovation Center for Regional Environmental Quality, Tsinghua University, Beijing, 100084, China.
School of Environment, Tsinghua University, Beijing, 100084, China; Graduate School at Shenzhen, Tsinghua University, Shenzhen, 518055, China.
Chemosphere. 2017 Aug;180:295-301. doi: 10.1016/j.chemosphere.2017.03.116. Epub 2017 Mar 31.
Vanadium (V) contamination in soils is an increasing worldwide concern facing human health and environmental conservation. The fractionation of a metal influences its mobility and biological toxicity. We analyzed the fractionations of V and several other metals using the BCR three-step sequential extraction procedure. Among methods for removing metal contamination, soil washing is an effective permanent treatment. We conducted experiments to select the proper reagents and to optimize extraction conditions. Citric acid, tartaric acid, oxalic acid, and NaEDTA all exhibited high removal rates of the extractable state of V. With a liquid-to-solid ratio of 10, washing with 0.4 mol/L citric acid, 0.4 mol/L tartaric acid, 0.4 mol/L oxalic acid, and 0.12 mol/L NaEDTA led to removal rates of 91%, 88%, 88%, and 61%, respectively. The effect of multiple washing on removal rate was also explored. According to the changes observed in metal fractionations, differences in removal rates among reagents is likely associated with their pK value, pH in solution, and chemical structure. We concluded that treating with appropriate washing reagents under optimal conditions can greatly enhance the remediation of vanadium-contaminated soils.
土壤中的钒（V）污染是全球范围内日益受到关注的人类健康和环境保护问题。金属的形态会影响其迁移性和生物毒性。我们使用BCR三步连续提取法分析了钒和其他几种金属的形态。在去除金属污染的方法中，土壤淋洗是一种有效的永久性处理方法。我们进行了实验以选择合适的试剂并优化提取条件。柠檬酸、酒石酸、草酸和NaEDTA对可提取态钒均表现出较高的去除率。在液固比为10的情况下，用0.4 mol/L柠檬酸、0.4 mol/L酒石酸、0.4 mol/L草酸和0.12 mol/L NaEDTA淋洗，去除率分别为91%、88%、88%和61%。还探讨了多次淋洗对去除率的影响。根据金属形态的变化观察，试剂之间去除率的差异可能与其pK值、溶液pH值和化学结构有关。我们得出结论，在最佳条件下用合适的淋洗试剂处理可以大大提高钒污染土壤的修复效果。
