PRB技术对PCBs及重金属污染地下水的试验研究

可渗透反应墙(Permeable Reactive Barrier PRB)技术是原位修复污染土壤及地下水的新型技术。试验以多氯联苯(PCBs)及重金属为靶污染物,设计3个PRB反应装置:柱Ⅰ、柱Ⅱ、柱Ⅲ,分别以还原铁粉、废料生铁、废料生铁与活性炭的混合物为反应介质,对PRB技术治理PCBs及重金属污染的地下水的可行性进行试验研究。试验结果表明:进入稳定期,柱Ⅰ、柱Ⅱ、柱Ⅲ对PCBs的去除效率分别为98%,97%,96%;对重金属(Cr、Cd、Pb、As)的去除效率均在97%以上。通过各柱处理,出水水质均达到地下水水质Ⅲ标准。说明PRB技术治理PCBs及重金属污染的土壤及地下水是可行的。

Experimental Study on Using PRB to Treat Groundwater Polluted by PCBs and Heavy Metal

PRB is a new technical type for in-situ remediation of polluted soil and groundwater. PCBs and heavy metals were selected as target contaminants in experiment. Reductive iron, scrap iron, scrap iron and active carbon mixture were respectively used in three kinds of permeable reactive barriers viz. columnⅠ,Ⅱand Ⅲ. The experiment was conducted to study the feasibility of the PRB technology which was used in remediation of groundwater polluted by PCBs and heavy metals. The results show that the PCBs removal ratios of columnⅠ,Ⅱand Ⅲ were respectively 98%,97%,96%. The heavy metals removal ratios of columnⅠ,Ⅱand Ⅲ were more than 97% in the stable time. Through the treatment of per column, the quality of water attained the Ⅲ standard of groundwater quality. The experiment indicated that the PRB technology is a feasible method for the treatment of soil and groundwater polluted by PCBs and heavy metal.