酒石酸淋洗过程中土壤重金属解吸动力学特征

采用批处理淋洗的方法,研究了酒石酸淋洗修复张士污灌区土壤过程中镉、铅、铜、锌4种重金属离子解吸动力学特征。结果表明,酒石酸在12h条件下,达到对污染土壤中镉离子的最大去除率,铅、铜、锌3种重金属离子达到最大去除率则需要24h。4种重金属离子的解吸动力学过程可以用Elovich方程很好的描述,说明酒石酸去除重金属离子的过程是一种非均相扩散过程。此外,解吸速率曲线显示,反应初期相同时刻上酒石酸对铅离子的解吸速率最快,其次是铜和锌,最后是镉离子;反应后期同一时刻上铜和锌的解吸速率大于铅和镉。

Kinetics Characteristics of Heavy Metals Desorption from Contaminated Soil during Tartaric Acid Leaching

The kinetics characteristics of four heavy metals,namely Cd,Pb,Cu,Zn,desorption from contaminated soil during tartaric acid leaching to restore Zhangshi sewage irrigation area were studied by batch experiments.The results showed that the maximum removal of Cd was within 12h,while the maximum removal of Cu,Pb and Zn were within 24h.Desorption behaviors of four heavy metals were described by Elovich model well.This meant desorption process belonged to heterogeneous diffusion.In addition,desorption rate curve indicated that the order of desorption rate was PbCu=ZnCd in the beginning of reaction,while the rates of Cu and Zn were faster than that of Pb and Cd at the end of reaction.