某农药厂场地土壤地下水污染修复指导值探讨

A study of contaminant remediation guidelines for soil and groundwater near an insecticide factory

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。

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 Ixg/kg for 1,2-dichloroethane and 67 ~Lg/kg for 1, 2-dichloro-propane. The groundwater guidelines are 5 ~Lg/L for both 1, 2-dichloroethane and 1, 2- dichloropropane. Tier 2 can adjust the Tier 1 guidelines based on a critical on-site survey. The seepage sink soil final remediation objectives are 11 txg/kg for 1,2-dichloroethane and 45 txg/kg for 1,2-dichloropropane. The groundwater final objectives are still 5 ~Lg/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 1,2- dichloroethane in protecting of DUA pathway became restrictive due to site-specific characteristics.