垃圾焚烧厂渗滤液处置工艺中溶解性有机物变化特性

采用“物化+生物处理+深度处理”组合工艺处理垃圾焚烧厂渗滤液,探索组合工艺对渗滤液的实际去除效果,考察渗滤液中溶解性有机物(DOM)的组成及其结构特性随组合工艺的变化规律,并对其机理进行了初步探讨.结果表明,当进水COD和氨氮的平均值分别为17825,1946mg/L时,组合工艺对渗滤液中COD和氨氮去除率均达到99%左右,出水COD、氨氮、色度分别为57mg/L、5mg/L、15倍.组合工艺对渗滤液DOM中腐殖酸(HA)、富里酸(FA)和亲水性有机物(HyI)的去除率均达到99%左右,对HA、FA、HyI削减显著的工艺单元分别为混凝2、厌氧和颗粒活性炭(GAC),削减率分别达到86%、77%和84%.出水HA、FA和HyI的COD浓度分别为10,23,6mg/L,其中分子量较小的FA为出水主要组分.随着组合工艺处理过程的进行,渗滤液中DOM的紫外区吸光度值显著下降,DOM的E254、E253/E203分别由1.55、0.64下降至0.012和0.024,说明DOM的芳香性和复杂程度显著降低,脂肪链芳香化合物逐渐增加;此外,E300/E400和E465/E665分别由2.65和2.17增加至9.78和8.03,表明渗滤液中溶解性有机物腐殖化程度不断降低,芳香构化程度不断减小.

Characteristics of dissolved organic matters in waste incineration plant leachate treatment process

A novel process combined with physicochemistry biological treatment and advanced treatment was employed to treat leachate from incineration plant. The actual removal efficiency, dissolved organic matters (DOM) composition structure characteristics and the mechanism were investigated. Results showed the total removal efficiencies of COD and NH4+-N achieved approximately 99%. The influent COD (17825mg/L) and NH4+-N (1946mg/L) could be degraded to the effluent COD (57mg/L) and NH4+-N (5mg/L) respectively. In the combination process, the total COD removal efficiencies of HA, FA and HyI reached approximately 99%. The process units of significant cut for humic acids(HA), fulvic acids (FA), hydrophilic (HyI) were coagulation 2, anaerobic, granular activated carbon(GAC), respectively. The removal efficiencies for HA, FA, HyI reached 86%, 77%, 84%, respectively. The effluent COD values of HA, FA and HyI were 10, 23 and 6mg/L, respectively, FA of small molecular weight was the major component. The DOM ultraviolet absorbance value dropped significantly during the treatment. E254 and E253/E203 decreased from 1.55 and 0.64 to 0.012 and 0.024, which indicated that the aromaticity and complexity of DOM reduced significantly.The content of aliphatic chain increased gradually during the treatment process. In addition, E300/E400 and E465/E665 increased from 2.65 and 2.17 to 9.78 and 8.03, which also illustrated that the humification and aromatization degree reduced constantly.