Fenton/化学沉淀法处理垃圾渗滤液的研究

Treatment of Landfill Leachate by Chemical Precipitation/Fenton Process

在分析和总结已有垃圾渗滤液处理技术的基础上,采用Fenton氧化和化学沉淀组合工艺开展了垃圾渗滤液的处理研究,并对工艺参数进行了优化。首先应用Fenton试剂对渗滤液进行氧化处理。实验表明,在p H为3、氧化时间为150min、Fe SO4·7H2O投加量为0.03 mol·L-1、H2O2/Fe2+投加比例为6∶1时,CODCr的去除率高达90.01%。再对经Fenton试剂处理过的垃圾渗滤液使用Mg Cl2·6H2O和H3PO4,在碱性条件下与渗滤液中的NH3-N发生化学反应,生成六水磷酸铵镁(Mg NH4PO4·6H2O)沉淀物。实验结果表明,在p H为9.5,试剂摩尔投加比n(NH4+)∶n(Mg2+)∶n(PO43-)=1∶1.3∶1.3的条件下,渗滤液中NH 3-N的去除率达到75.7%,CODCr最终去除率为93.1%。

Fenton oxidation and the chemical precipitation method were adopted to treat landfill leachate, and the process parameters were optimized. First, landfill leachate was oxidized with Fenton reagent, the result showed that the removal rate of CODCr was 90.01% when the conditions were: pH=3, 150mins of oxidation time, the dosage of FeSO4 · 7H2O 0.03mol/L, and the addition ratio of H2O2/Fe2+ was 6:1. Secondly, MgCl2 · 6H2O and H3PO4 were put in the landfill leachate, which were dealt with Fenton reagent,and occurred a series of chemical reactions when meeting NH3-N in the leachate under the alkaline conditions, then the sediment of MgNH4PO4 · 6H2O was produced. The removal rates of NH3-N and final CODCr could reach 75.7% and 93.1% respectively under these conditions: pH=9.5, drug addition ratio NH4+:Mg2+:PO43- =1:1.3:1.3.