改良剂对铜镉污染土壤的修复效果及健康风险评估

    Long-Term Remediate Effect of Three Amendments on Polluted Soil Near Guixi Smelter and Health Risk Assessment

    • 摘要: 为了解磷灰石、石灰、木炭对贵溪冶炼厂周边重金属污染土壤的修复效果,通过化学浸出等方法研究了修复后第1年(2010年)和第4年(2013年)土壤中Cu和Cd的可浸出性、有效态(CaCl2)和生物可给性。结果表明,添加磷灰石、石灰和木炭显著增加了土壤pH值,降低土壤交换性酸和交换性铝含量。改良剂的添加降低了土壤中Cu和Cd的可浸出性和有效态,且磷灰石和石灰处理效果优于木炭,但随着时间推移处理效果减弱。磷灰石和石灰处理1 a后土壤的Cu生物可给性较对照分别降低28.6%和23.1%,Cd生物可给性分别降低21.7%和22.8%,第4年Cu和Cd的生物可给性均有上升趋势。另外,改良剂处理后Cu和Cd的风险系数(QH)均小于1,儿童的风险系数均大于成人。总体上,磷灰石处理在降低Cu和Cd可浸出性、有效态和生物可给性方面具有更好的效果。

       

      Abstract: The leachability (toxicity characteristic leaching procedure),availability (CaCl2) and bioaccessibility (simplified bioaccessibility extraction test) of Cu and Cd were evaluated after application of apatite, lime and charcoal for the first year(2010) and fourth year(2013) by chemical extractable methods. Results show that addition of apatite, lime and charcoal increased soil pH and decreased the concentrations of exchangeable acid and aluminum. Moreover, applications of lime and apatite were more effective in reducing the contents of leachable and available Cu and Cd than the charcoal treated soil, but the immobilization effect was reduced over time. Applications of apatite and lime significantly decreased bioaccessibility of Cu by 28.6% and 23.1%, respectively, and bioaccessibility of Cd by 21.7% and 22.8%, respectively, in 2010, but bioaccessibility of Cu and Cd were increased in the 2013 than those in 2010. The health risk coefficient (QH) of Cu and Cd for people were all lower than 1. Nevertheless, it should be noted that QH values for the children were higher than those for adults. Compared to lime and charcoal, apatite was the most effective in decreasing leachability, availability and bioaccessability of Cu and Cd.

       

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