基于用途和风险的重金属污染土壤稳定化修复后评估体系探讨

摘要

系统总结了国内外用于评估重金属污染土壤稳定化修复效果的方法及存在的问题. 目前国内外土壤稳定化效果评估多采用模拟填埋和酸雨情景下的毒性浸出方法,但该评估方法不能完全模拟基于填埋、绿化、路基和河岸护坡等不同用途和去向后污染物向环境中释放的多种情景,也很难表征碳化、冻融等实际复杂多变环境的长期作用下重金属释放的风险. 提出应基于土壤稳定化修复后的不同用途和去向,建立相应的浸出方法,评估不同环境胁迫条件下重金属释放的可能性及浸出量,同时建立稳定化土壤的健康和生态风险评估方法以评价其存在的潜在风险,尝试构建稳定化土壤的浸出和风险评估方法体系.%Domestic and international standard methods were reviewed and the existing problems pointed out on assessment of stabilization effect for heavy metals contaminated soil.At present, the method of toxicity leaching under the simulated scenarios of landfilling and acid rain is mostly adopted for the assessment.However, this assessment method cannot completely simulate the release of pollutants into the surrounding environment for different purposes, such as gardening soil, road construction, embankment, etc.It is also difficult to characterize the release risk of heavy metals under the long-term effects of the actual complex environments such as carbonization and freeze-thaw, etc.The appropriate leaching methods should be established based on different reuse and disposal scenarios of the stabilized soil, to assess the possibility and amount of heavy metals release under different environmental stress conditions.The health and ecological risk assessment methods should be built up to evaluate the potential risk of the stabilized soil.Through these attempts, the framework of leaching and risk assessment methods for the stabilized soil could be formed.