“老龄期”填埋场渗滤液COD蒸发规律研究

Study on the evaporating rule of COD from old landfill leachate

“老龄期”填埋场渗滤液由于可生化性差而难于处理。采用常规蒸发、减压蒸发和载气蒸发处理不同pH值的“老龄期”渗滤液。实验结果表明,3种蒸发方式下,冷凝液COD下降过程中均存在明显的浓度转折点,转折点之后COD维持较低水平,为“老龄期”渗滤液的“三分处理法”提供理论依据。与常规蒸发相比,减压蒸发和载气蒸发的前期冷凝液COD较高,且浓度转折点偏后。

It is difficult to treat old landfill leachate for its low biodegradability. Normal evaporation, vacuum evaporation and gas-carrying evaporation were adopted for treatment of old landfill leachate with different pH values. The results show that, for three types of evaporation tests, there always exist clear turning points of concentrations along with the decrease of condensates COD in the process of evaporation, and COD keeps on the low level after these points. This fact means old landfill leachate can be divided into three parts to be treated respectively. For vacuum evaporation and gas-carrying evaporation, the earlier-stage condensates COD are higher and the turning points are later than normal evaporation.