PRB修复垃圾渗滤液污染地下水过程中NH_4^+的变化规律

Variation of NH_4^+ in Leachate-polluted Groundwater Under Condition of PRB Remediation

实验模拟地下水修复,以被垃圾渗滤液污染地下水为研究对象,分别用沸石、无烟煤、陶粒、活性炭、炉渣、钢渣、粉煤灰、零价铁作为填充材料,设计6种可渗透反应墙(PRB),分别为反应器1、2、3、4、5和6。分3个试验阶段对PRB技术修复污染地下水中NH4+变化规律进行实验模拟研究,分析了反应器NH4+变化原因并探讨了NH4+变化机理。实验结果表明:NH4+去除率普遍较低,含沸石反应器脱氮效果最好,也仅为49.8%,部分反应器甚至出现负值;水解酸化作用,产生一定量NH4+和有机酸,造成反应器出水pH值降低和填充材料NH4+相对去除率偏低。PRB技术治理渗滤液污染地下水具有一定可行性,但技术有待继续深入研究。

The groundwater remediation was modeled by using zeolite, anthracite, haydite, activated carbon, steel slag, slag, coal-dust ash, and Fe~ as filling materials and six Permeable Reactive Barriers （PRBs, reactorl, 2, 3, 4, 5 and 6 respectively） were designed to research on the leachate-pollutcd groundwater. Experiments on the variation of NH4＋ in leachate-polluted groundwater under the condition of PRB remediation were modeled for three stages and the mechanisms ofNH4＋ variation in reactors were discussed. The results showed that the removal rates ofNH4＋ were low, zeolite reactor for denitrification was better than others, and its ability for removal rate of NH4＋ was 49.8%, negative values for denitrification were observed in some reactors, which may be caused by the hydrolysis and acidification since they could produce NH4＋ and organic acids. The above results proved that actual treatment capacities of filling materials were not expressed fully the experimental results. Therefore, PRB technology for the treatment of leachate-poUuted groundwater is feasible under the condition of further study.