基于精准调查的污染场地模型研究

Research on the Model of a Polluted Site Based on Precise Investigation

以天津某污染场地为对象,开展了污染识别、初步采样及补充分层监测,依次构建了初步场地概念模型、污染表征概念模型、地下水流溶质运移数值模型,更新优化的场地概念模型能够直观地展示污染空间分布与地层结构,明确污染成因。结果表明,该场地以氯代烃类污染为主,污染物以独立污染源为中心向四周扩散,且多积聚在浅层潜水层,粉质黏土层有效阻滞了其垂向迁移。数值模型污染预测结果表明,污染区域范围内的污染物质量浓度随时间的延长而降低,对流弥散作用对其影响较小。基于精准调查建立的场地概念模型与数值模型相结合的方法,可为掌握场地实际污染状况及后期管理决策提供数据支撑。

Taking a site in Tianjin as the object,this paper carried out pollution identification,preliminary sampling and supplementary stratified monitoring,and constructed a preliminary site conceptual model,a pollution characterization conceptual model,and a groundwater flow-solute transport numerical model in sequence.The update and optimization of the conceptual model of the site intuitively connects the spatial distribution of pollution and the stratigraphic structure,and clarifies the causes of pollution.The results indicate that the site is mainly polluted by chlorinated hydrocarbons,and the pollution spreads around from independent pollution sources,and mostly accumulates in shallow diving,and the silty clay layer effectively blocks its vertical migration.The numerical model pollution prediction showed that the pollutant content decreased with time,and the convection dispersion had little effect on it.The method of combining the conceptual model of the site with the numerical model based on the accurate survey provides a working basis for grasping the actual pollution of the site and later decision-making.