模拟酸雨对土壤修复中重金属淋溶特征及土壤持水能力的影响

以磷酸二氢钾（PDP）钝化后的重金属污染土壤为研究对象,通过室内土柱淋溶和土壤吸水实验,考察pH为3.1、4.6和5.1的模拟酸雨对污染土壤修复过程中重金属淋溶特征及土壤持水能力的影响。实验结果表明：PDP处理显著增加了淋出液的pH、电导率、TOC和正磷酸盐态磷（ZP）含量,在淋溶初期显著降低了淋出液的Cu、Cd和Pb含量,但在淋溶后期增大了Pb含量;土壤持水量与电导率、pH、TOC和ZP含量呈现极显著负相关性;土壤修复过程中,有机质的淋失、盐分含量及pH的增大可引起土壤持水能力的减弱。

Effects of simulated acid rain on leaching characteristics of heavy metals and water-retaining capacity of soil in soil remediation

The effects of simulated acid rain （SAR） with pH of 3.1,4.6 and 5.1 on leaching characteristics of heavy metals and water-retaining capacity of contaminated soil passivated with potassium dihydrogen phosphate （PDP） in soil remediation were investigated by a laboratory column leaching experiment and a water absorption experiment. The experimental results show that：The pH,conductivity,TOC and orthophosphate （ZP） contents of the eluate are significantly increased by PDP treatment,and the contents of Cu,Cd and Pb in the eluate are significantly reduced in the initial leaching period,but the Pb content is increased in the later stage;There is a significant negative correlation between water-retaining capacity of soil and conductivity,pH,TOC and ZP content;During the process of soil remediation,the water-retaining capacity of the soil can be reduced due to the leaching of organic matter and the increases of salt content and pH.