某农药厂场地土壤地下水污染修复指导值探讨

摘要

To calculate remediation objectives for 1,2-dichloroethane and 1,2-dichloropropane in soil and groundwater near a insecticide factory, procedures Tier 1 and Tier 2 were chosen from the Canadian Alberta SGRG tiered approach model.By using parameters suitable for our country, the generic Tier 1 guidelines were developed.The guidelines of the seepage sink soil are 6.2 μg/kg for 1,2-dichloroethane and 67 μg/kg for 1, 2-dichloro-propane.The groundwater guidelines are 5 μg/L for both 1, 2-dichloroethane and 1, 2dichloropropane.Tier 2 can adjust the Tier 1 guidelines based on a critical on-site survey.The seepage sink soil final remediation objectives are 11 μg/kg for 1,2-dichloroethane and 45 μg/kg for 1,2-dichloropropane.The groundwater final objectives are still 5 μg/L for both 1,2-dichloroethane and 1,2-dichloropropane.The adjustment of the guidelines was in accordance with the tiered approach theory.Note that the value of 1,2dichloroethane in protecting of DUA pathway became restrictive due to site-specific characteristics.%参考加拿大Alberta SGRG层次性分析模式,选择其中Tier 1、Tier 2两层次进行分析,结合适合我国的参数计算出了某农药厂土壤地下水中的有机污染物1,2-二氯乙烷、1,2-二氯丙烷修复值,得到了通用的Tier 1修复指导值分别为:渗坑土壤中1,2-二氯乙烷6.2μg/kg,1,2-二氯丙烷67μg/kg;场地地下水中1,2-二氯乙烷、1,2-二氯丙烷均为5μg/L.在此基础上,结合实地调查获取场地参数,利用Tier 2评价对指导值进行修正,确定了场地最终修复目标值:渗坑土壤中1,2-二氯乙烷为11μg/kg,1,2-二氯丙烷为45μg/kg;地下水中1,2-二氯乙烷、1,2-二氯丙烷仍为5μg/L.各途径修复值的改变较符合层次性评价的理论,即Tier 2修复值较Tier 1宽松;但1,2-二氯丙烷的保护DUA途径修复值较Tier 1更加严格,这是由于场地特定条件造成的.