蒸发气相吸收耦合方法处理垃圾渗滤液

Evaporation and vapor absorption coupling method for landfill leachate treatment

对垃圾渗滤液蒸发、蒸发-气相酸吸收、蒸发-气相碱吸收和蒸发-气相酸吸收-气相碱吸收处理进行了试验研究,考察了不同工艺真空度和渗滤液初始pH对冷凝液水质的影响。结果表明:采用蒸发法时,随着真空度的升高,冷凝液pH、NH_(3)-N浓度和总含盐量(TDS)值均呈下降趋势,而COD浓度逐渐增加。当初始渗滤液呈酸性时,冷凝液中NH_(3)-N的含量较低,而COD的含量较高;当初始渗滤液呈碱性时,冷凝液中COD的含量较低,而NH_(3)-N的含量较高。采用蒸发-气相酸吸收法可有效降低渗滤液中NH_(3)-N的含量,采用蒸发-碱吸收法可去除渗滤液中的COD。采用蒸发-气相酸吸收-气相碱吸收法能同时降低渗滤液中COD、NH_(3)-N和TDS的浓度,在渗滤液初始pH为8.1的条件下,对渗滤液中COD、NH_(3)-N和TDS的去除率均达99%以上,浓度分别降至60mg/L、8mg/L和10mg/L以下,冷凝液水质符合GB 16889—2008对环境敏感地区的排放标准。

Experimental studies on landfill leachate treatment by evaporation,evaporation-vapor acid absorption,evaporation-vapor alkali absorption and evaporation-vapor acid absorption-vapor alkali absorption were carried out,and the effects of vacuum degree and initial pH of leachate on condensate water quality when using different processes were investigated.The results showed that when the evaporation process was adopted,as the vacuum degree increased,pH,NH_(3)-N concentration and TDS value in condensate all presented a downward trend,while COD concentration went up gradually.When the initial leachate was acidic,NH_(3)-N content in condensate was low,while COD content was high;when the initial leachate was alkaline,COD content in condensate was low,while NH_(3)-N content was high.The evaporation-vapor acid absorption process could efficiently reduce NH_(3)-N content in leachate,and the evaporation-vapor alkali absorption process could remove COD in leachate.The evaporation-vapor acid absorption-vapor alkali absorption process could simultaneously decrease COD,NH_(3)-N and TDS concentration in leachate.Under the initial pH 8.1 of leachate,the removal of COD,NH_(3)-N and TDS in leachate all exceeded 99%,and their concentration dropped below 60mg/L,8mg/L and 10mg/L,respectively.The condensate quality complied with GB 16889—2008 discharge standard for environmentally sensitive areas.