强化的零价铁PRB技术对PCBs污染地下水的修复

本实验强化了零价铁可渗透反应墙（Permeable Reactive Barrier,PRB）技术,分别用还原铁粉、还原铁粉＋锌粉、还原铁粉＋活性炭为主要的反应介质,以Arcolor1242为靶污染物,对强化的零价铁PRB技术治理多氯联苯污染的地下水的可行性和有效性进行了模拟研究。实验结果表明：在温度10℃,有效孔隙率为61%~67%,水的渗透速度为0.7~0.8 m.d-1的条件下,3个反应柱稳定期对PCBs的去除率分别达到94%、85%、79%,pH值从6.87升高到8.78、10.2、7.93;氧化还原电位从-48.6 mV降到-135、-107、-86.4 mV;出水铁离子的平均质量浓度为0.241、0.129和0.201 mg.L-1,脱氯率平均值为49.6%、72.6%、58.6%。综合考虑处理效果与成本,用零价铁PRB技术治理PCBs污染的地下水是可行的。

Enhanced Fe0 PRB technology for the remediation of PCBs contaminated groundwater

In this paper,column experiments were conducted to enhance the performance of the Fe0 based Permeable Reactive Barrier（PRB） technology by utilizing Fe0,Fe0/Zn0and Fe0/activated carbon as the reactive materials.Three laboratory columns were set up and operated under conditions simulating those anticipated in groundwater to investigate the feasibility and efficiency of the enhanced Fe0 PRB for the treatment of the PCBs contaminated groundwater.Operating under 10 ℃ and an effective porosity of 61% to 67% and infiltration velocity of groundwater of 0.7 to 0.8 m.d-1,the columns can accomplish 94%,85% and 79% of PCBs removal,respectively,pH value raised to 8.78,10.2,7.93 and Eh value decreased to-135,-107 and-86.4 mV and the average iron concentration of effluent was 0.241,0.129 and 0.201 mg.L-1,respectively,and the average dechlorination efficiency reached 49.6%,72.6% and 58.6%,respectively.Comprehensive consideration suggested that Fe0 based PRB technology is feasible for the remediation of PCBs contaminated groundwater.