摘要
以某含1,2-二氯乙烷等10种有机物污染土壤回填项目为例,介绍了2种方法(三相平衡耦合地下水稀释模型和Sesoil耦合地下水稀释模型)在评估土壤污染对地下水影响中的具体应用并进行了比较.结果表明,采用US EPA(美国国家环境保护局)推荐的三相平衡耦合地下水稀释模型预测的地下水中目标污染物浓度高于新泽西州推荐的Sesoil耦合地下水稀释模型的3~10倍,污染物亨利常数及碳水分配系数越高,二者的差异越明显,达到1个数量级.对于多环芳烃类的强疏水性有机污染物,2种方法的评估结论无本质差异.出于保守性及调查成本的考虑,在制订国家或区域范围基于保护地下水的土壤通用筛选值时,建议采用所需参数相对较少的三相平衡耦合地下水稀释模型的方法,以节约调查成本.对于具体评估项目,当污染物浓度超过通用筛选值时,建议进一步对场地水文地质条件进行调查,采用Sesoil耦合地下水稀释模型重新评估并计算该特定场地的筛选值,以节约修复成本.
Two assessment methods, three-phase equilibrium in combination with groundwater dilution model recommended by US EPA and Sesoil in combination with groundwater dilution model recommended by New Jersey, were compared for evaluating impacts on groundwater through backfilling soil contaminated by 1,2-dichloroethane and other 9 organic pollutants. The results showed that the concentrations of the 10 contaminants in groundwater predicted by the US EPA method were 3-10 times of those predicted by the New Jersey method. The difference was much more obvious by an order of magnitude, when the Henry' s law constants and the carbon-water adsorption factors of the contaminants were high. However, the difference was not significant regarding to strong hydrophobic contaminants such as PAHs. Generally, the method recommended by US EPA was conservative and needs less parameter inputs, which would be a cost saving tool. Moreover, this method could be applied to drive general soil screening levels at the national level or regional scale to protect groundwater. In a case that concentrations of contaminants in soil were higher than the corresponding general screening values, further intensive hydro-geological investigation and sophisticated Sesoil with groundwater dilution model is recommended for further evaluation or calculation of the site-specific screening to save the remediation costs.
出处
《环境科学研究》
EI
CAS
CSCD
北大核心
2013年第7期793-799,共7页
Research of Environmental Sciences
基金
北京市科学技术委员会重大项目(D08040000360000)
中意污染场地管理国际合作项目
关键词
土壤污染
地下水水质影响
三相平衡模型
Sesoil模型
地下水稀释模型
soil contamination, impact to groundwater quality
three-phase equilibrium model
Sesoil model
groundwater dilution model