石灰性污染土壤中重金属镉、铅的活化研究

为了探讨石灰性污染土壤中重金属的活化方法，选择四种试剂（氯化钠、盐酸、EDDS和柠檬酸）和受镉污染和镉、铅复合污染两种土壤（XX土壤，全镉6.77 mg kg?1，< 0.01 mm颗粒含量9.8%；JY土壤全镉5.72 mg kg?1、全铅312 mg kg?1，< 0.01 mm颗粒含量29.8%）进行室内培养试验。结果表明:对于XX土壤，氯化钠、盐酸、EDDS和柠檬酸对镉均有活化作用，活化效率分别达到71.87%、74.87%、43.27%和22.86%；对于JY土壤，氯化钠、盐酸和EDDS对镉的活化效率分别达到53.44%、48.44%和42.4%，柠檬酸的活化作用不明显，氯化钠、盐酸、EDDS和柠檬酸对JY土壤铅的活化效率分别达到26.49%、25.56%、55.21%和14.81%。土壤质地可能是影响两种土壤中不同试剂重金属活化效率的主要因素。

Activation of Heavy Metals Cd and Pb in Contaminated Calcareous Soils

In order to explore the activation methods of heavy metals in calcareous soils, four chemicals (NaCl, HCl, EDDS and citric acid) were added to two soils (XX soil, total Cd: 6.77 mg kg?1, < 0.01 mm particle: 9.8%; JY soil, total Cd: 5.72 mg kg?1, total Pb: 312 mg kg?1, < 0.01 mm particle: 29.8%) and then cultivated. The results showed that the activation efficiency of NaCl, HCl, EDDS and citric acid on Cd were 71.87%, 74.87%, 43.27% and 22.86% in the XX soil, respectively. The activation efficiency of NaCl, HCl and EDDS on Cd were 53.44%, 48.44% and 42.4% in the JY soil, respectively, while the activation effect of citric acid on Cd was negligible. The activation efficiency of NaCl, HCl, EDDS and citric acid on Pb were 26.49%, 25.56%, 55.21% and 14.81% in the JY soil, respectively. Our study indicated that soil texture may play an important role on the activation efficiency of heavy metal in these two soils.