垃圾渗滤液对地下水污染的PRB原位处理技术

以被垃圾渗滤液污染的地下水为研究对象,分别用零价铁、零价铁和活性炭、零价铁和沸石的混合物作为反应介质,设计了3种地下可渗透反应器(PRB),分别为反应器A、B和C,对PRB技术治理污染地下水的可行性和有效性进行实验模拟研究.反应器的设计充分考虑了反应器的渗透能力与周围地层介质渗透能力的关系.实验结果表明:反应器A、B、C对COD的去除率分别达到80%、90%、70%以上,BOD₅/COD值由0.32分别升高至0.781、0.728、0.716,总氮从50mg/L都降到10mg/L以下,NH₄⁺的去除率达到78%～91%.反应器C中的沸石对重金属和硬度表现出良好的去除效果,其中Mn、Zn离子和硬度的去除率分别达到90%、80%和81%,说明PRB技术治理渗滤液污染的地下水是可行的.

PRB Technology in Situ Remediation of Groundwater Polluted by Landfill Leachate

In this paper three reaction media zero valent iron (ZVI), a mixture of ZVI and activated carbon, a mixture of the ZVI and zeolites were used to design three kinds of permeable reactive barrier (PRB), viz. reactors A, B and C and to study the feasibility and the efficiency of the PRB technology in the remediation of leachate-polluted groundwater. The designs of the reactors took into account the relation of the permeability of the reactor with the permeability of the aquifer. The results indicated that the COD removal ratios of the reactor A, B and C were more than 80%, 90% and 70% respectively and the value of the BOD5/COD increased from 0.32 up to 0.781, 0.728, 0.716 respectively. Total nitrogen decreased from 50 mg/L to less than 10 mg/L and the removal ratio of the ammonium ranged from 78%-91%. Zeolites of the reactor C manifested effectiveness in the removal of heavy metals and hardness. The removal ratios of Mn ion, Zn ion and hardness were up to 90%, 80%, 81% respectively. These results indicate that PRB technology is an efficient method for the treatment of leachate-contaminated groundwater.