原位阻隔技术在遗留污染场地治理中的应用

Application of in-Situ Barrier Technology in the Treatment of Remaining Contaminated Sites

结合实际工程案例,总结了原位阻隔技术在遗留污染场地治理中的应用经验,主要涉及治理目标确定、总体技术方案的比选、垂直防渗系统的建立、封场技术等。场地修复目标的确定和技术路线的选择应以风险评估结论为基础,并综合考虑土地利用规划、修复时间、修复成本等因素。生态阻离区的划定应尽可能封存控制绝大部分污染土壤,减小污染土壤开挖量;垂直防渗墙结构形式应综合考虑墙体渗透性要求、地层岩土性质、施工成本、作业空间等因素综合确定,墙体渗透系数应达到10~(-7) cm/s数量级,垂直防渗墙底部进入相对不透水层的深度不小于2 m,可同步采取帷幕灌浆、地下水抽提方式。

Combined with practical engineering cases,the application experience of in-situ barrier technology in the treatment of contaminated sites was summarized,mainly involving the determination of treatment objectives,the comparison and selection of overall technical schemes,the establishment of vertical seepage control system,and field closure technology.The determination of site restoration objectives and the selection of technical routes should be based on the conclusion of risk assessment,and the factors such as land use planning,restoration time and restoration cost should be comprehensively considered.The delineation of ecological isolation area should seal and control the vast majority of contaminated soil as much as possible,and reduce the excavation amount of contaminated soil.The structure form of vertical cut-off wall should comprehensively consider the permeability requirements of the wall,the rock and soil properties of the stratum,the construction cost and the working space.The permeability coefficient of the wall should reach the order of 10-7 cm/s.The depth of the bottom of the vertical cut-off wall entering the relative impervious layer was not less than 2 m,and the curtain grouting and groundwater extraction can be adopted simultaneously.