生活垃圾焚烧厂贮坑沥滤液的负压蒸发预处理研究

采用负压蒸发法处理上海市某大型生活垃圾焚烧发电厂贮坑沥滤液,实验研究了沥滤液蒸发过程中冷凝液组分的变化特征.结果表明:生活垃圾焚烧厂贮坑沥滤液中含有高质量浓度的挥发性污染物,低碳醇和碳原子数不大于7的挥发性有机酸(VFA)约占沥滤液中有机碳质量浓度的50%;沥滤液直接蒸发可将原液转化为原液量的84%,不含氨氮,有机物质量浓度为原液的21%,且90%以上为VFA及低碳醇的冷凝液,以及有机物质量浓度浓缩了4.4倍,适于焚烧处理的浓缩液;通过蒸发处理,沥滤液的处理难度大大降低,蒸发用能可取自焚烧热能回收后的低温位热能,降低了蒸发处理的费用. 

Study on Pretreatment of Leachate from Refuse Storage Pit in Municipal Solid Waste Incinerator by Vacuum Evaporation

Leachate from refuse storage pit(LRSP) of a municipal solid waste incinerator(MSWI) located in Shanghai was treated by vacuum evaporation process.The variation characteristics of the condensate components in the evaporation process of the leachate were analyzed.The results showed that the LRSP has high mass concentration of volatile organic matters,mainly composed of low molecular weight alcohols and volatile fat acids(VFA) with the formula number of the carbon less than seven,which account for about 50% organic carbon in the LRSP.84% of LRSP and 21% organic matter of the original LRSP could be transferred into the condensate,where no ammonia was detected.More than 90% of the organic matters in the condensate were composed of VFA and alcohols.The residual liquid,whose mass concentration of organic matters was 4.4 times of the original LRSP,could be further disposed by incineration.It was easier to treat the products from LRSP evaporation than that of the original LRSP.The recovered energy from the MSWI could be utilized for the evaporation process,which can reduce the cost of evaluation treatment.