回灌对垃圾填埋初期渗滤液化学需氧量的影响

Influence of recirculation operations on chemical oxygen demand of leachate in the initial landfill stage

通过模拟柱实验 ,研究了回灌对垃圾填埋场初期渗滤液 CODCr的影响。研究结果表明 ,模拟降雨雨水的渗入且无渗滤液回灌的参照柱 ,其渗滤液出水 CODCr最高 ,一般在 70 0 0 0 mg/L 左右 ;模拟渗滤液原液回灌 ,从第 4周起因脂肪酸的积累导致渗滤液的 p H低于 6,从而抑制了微生物的生化反应 ;模拟好氧生物处理后渗滤液的回灌 ,能加速垃圾层 CODCr的溶出和甲烷化阶段的建立 ,且此时渗滤液的 CODCr变化规律符合指数方程 ;当垃圾层建立甲烷化阶段后 ,回灌 CODCr在 2 0 0 0 0 m g/L 左右的渗滤液 。

The influence of recirculation operations on chemical oxygen demand (COD Cr ) of leachate in the initial landfill stage was studied through simulation columns experiment. The experimental results indicated that the COD Cr value in the outlet of leachate of the reference column, which simulated the infiltration of runoff without leachate recirculation, was the highest around 70,000 mg/L. Microorganism metabolism was restrained when the pH value was under 6 as a result of fatty acid accumulation in the column after 4th week with direct recirculation of non\|pretreatment leachate. The recirculation of aerobic\|treated leachate, accelerated the dissolution of the materials which was shown as COD Cr and start\|up of the methane\|producing phase in the landfill. In this case, the change of COD Cr with time could be expressed with exponential equation. After the methane\|producing phase in the landfill had been set up, the transformation of the organic matter from solid to gaseous state was still accelerated by the recirculation of leachate with the COD Cr value around 20,000 mg/L.