不同活化剂对镉、铅单一及复合污染土壤的修复效果影响

选取柠檬酸(CA)、木醋液(WV)、聚天冬氨酸(PASP)、羟基乙叉二磷酸(HEDP)和FeCl3作为活化剂,以镉、铅单一和复合污染土壤为研究对象,采用振荡淋洗法结合形态分析技术研究活化剂对重金属污染土壤的修复效果。结果表明:(1)重金属单一污染时,5种活化剂对镉、铅均有一定的淋出效果,淋出效率均随活化剂浓度的增大而增大。活化剂通过淋洗实验主要淋出酸溶态和可还原态重金属。(2)重金属复合污染时,金属离子间的竞争作用会不同程度地影响重金属在土壤中的存在形态,进而影响重金属的淋出效率,多数情况下,铅的存在会促进镉的淋出,但镉的存在会抑制土壤铅的释放。

Effect of different activators on the remediation of Cd and Pb single and compound contaminated soils

The oscillating elution method combined with morphological analysis technique was used to investigate the effect of different activators such as citric acid,wood acetic acid,PASP,HEDP and FeCl3 on the activation and remediation of Cd and Pb single and compound contaminated soils.The results showed that:(1)the five activators had a certain leaching effect on Cd and Pb,and the leaching rate increased with the increasing of activator concentration for a single heavy metal-contaminated soil.The acid-soluble and reducible heavy metals was mainly removed by the activator.(2)For complex heavy metal-contaminated soils,in most cases,the leaching rate of cadmium was higher due to the presence of lead,but the release of lead was inhibited by the presence of cadmium,the competition between different metal ions had different effects on the presence of heavy metals,and further influence the leaching effect of heavy metals.