垃圾渗滤液的微波增效GAC载铁催化Fenton氧化处理

Treatment of Landfill Leachate via Fenton Oxidation Process Catalyzed by Fe^(2+) Loaded on GAC and Enhanced by Microwave

以载Fe2+颗粒活性炭(GAC)作为催化剂,采用微波增效Fenton试剂氧化工艺处理老龄垃圾渗滤液;以COD和NH3-N的去除率为指标,分析了Fe2+负载量、GAC用量、微波处理时间、微波处理功率、H2O2用量以及处理液pH值对垃圾渗滤液Fenton氧化处理效果的影响,并进行微观分析及动力学探讨.结果表明:微波可以增强Fenton氧化效果,并促进渗滤液中胶体的絮凝,其中COD主要通过催化氧化作用去除,而NH3-N主要通过絮凝、吸附作用去除;当Fe2+的负载量为33.32mg/g、GAC用量为10g/L、微波处理功率为720 W、微波处理时间为30 min、30%H2O2的用量为0.10 mol/L、溶液初始pH=3时COD和NH3-N的去除率最高,分别达93.01%和85.76%;处理后垃圾渗滤液中有机污染物特征峰消失或大幅减弱,处理效果较好.文中还根据实验结果初步建立了微波增效Fenton试剂氧化反应的动力学模型.

In this investigation, with the granular activated carbon （GAC） loaded with Fe2＋ as the catalyst, the microwave-enhanced Fenton reagent oxidation process was adopted to treat aged landfill leachate. Then, the COD and NH3-N removals were taken as the indexes to analyze the influence of the Fe^2＋ loading amount, the GAC dos- age, the microwave treatment time, the microwave power, the H202 dosage and the treatment solution＇ s pH value on the Fenton reagent oxidation. The corresponding mieroanalysis and kinetics were also carried out. The results in- dicate that （ 1 ） microwave can enhance the Fenton oxidation and promote the colloidal flocculation in the leachate ; （2） the COD removal is mainly due to the oxidation, while the NH3-N removal is mainly due to the flocculation and adsorption ; （3） the maximum COD and NH3-N removals are respectively up to 93.01% and 85.76% in opti- mal conditions, namely, an Fe2＋ loading amount of 33.32rag/g, a GAC dosage of 10g/L, a microwave power of 720 W, a microwave treatment time of 30 min, a concentration of 30%H202 of 0. lOmol/L and an initial pH value of 3 ; and （4） the characteristic peaks of the organic pollutants in the treated landfill leaehate disappear or signifi- cantly weaken, which means that the proposed process is preferable. In addition, a kinetics model of microwave- enhanced Fenton reagent oxidation reaction is preliminarily established according to the experimental rasnlts.