PRB修复垃圾渗滤液污染地下水过程中NH4+ 的变化规律

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。

Variation of NH4+ in leachate-polluted groundwater under condition of PRB remediation

The groundwater remediation was modeled by using zeolite, anthracite, haydite, activated carbon, steel slag, slag, coal-dust ash, and Fe0 as filling materials and six Permeable Reactive Barriers (PRBs, reactor1, 2, 3, 4, 5 and 6 respectively) were designed to research on the leachate-polluted 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 of NH4+ variation in reactors were discussed. The results showed that the removal rates of NH4+ 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-polluted groundwater is feasible under the condition of further study.