化学/生物联合PRB技术去除地下水中的硝酸盐

Chemical /Biological PRB Technology for Removing Nitrate from Groundwater

设计了三层结构可渗透反应格栅(PRB),进行了地下水硝酸盐污染处理的可行性研究。反应柱按水流方向依次填充零价铁、锯末和沸石,利用化学、生物作用去除硝酸盐,再通过沸石吸附去除化学还原产生的氨氮。试验结果表明:反应柱启动迅速,第3天对硝酸盐氮的去除率已达到99.68%;稳定运行期间,出水中的"三氮"浓度均保持在较低水平,pH值最高为8.64,未超过pH值=10的微生物生存环境极限,由此认为采用多层结构化学/生物联合PRB技术去除地下水中的硝酸盐是可行的。

A three-layer permeable reactive barrier（PRB）was designed to study the feasibility for treatment of groundwater polluted by nitrate. Zero-valent iron, sawdust and zeolite were filled along the flow direction in the packed column. Chemical and biological methods were used to remove nitrate, and ammonia generated by the chemical reduction was adsorbed by zeolite. The results indicated that the packed column started up fast, and the removal rate of nitrate reached 99.68% on the third day. The contents of ammonia, nitrate and nitrite were maintained at a low level. The maximum pH value was 8.64, less than the limit of 10 for microbial survival environment. Hence, it is feasible to remove nitrate from groundwater by multi-layer chemical/biological PRB technology.