萃取-吸附法处理辛醇废碱液

摘要

辛醇废碱液中含有大量有机物，为此开展了萃取-大孔树脂吸附法处理辛醇废碱液、高效回收有机物的实验研究，实验结果表明：当辛醇废碱液的ρ(COD)为104651mg/L时，以辛醇为萃取剂，在pH=3、辛醇与辛醇废碱液的体积比为0.5、萃取级数为2等条件下，出水ρ(COD)可降至6453mg/L以下，COD去除率达到93.8%以上，萃取剂辛醇可以通过精馏再生循环利用；采用 HYA-106大孔吸附树脂对辛醇二级萃取出水进行吸附处理， HYA-106大孔吸附树脂较佳的吸附流速为1BV/h、温度为40℃，此时出水ρ(COD)平均在155～183mg/L之间， COD去除率在97.1%～97.4%之间，单位体积树脂的废水处理量为34BV以上，树脂吸附量在213～215mgCOD/mL树脂之间，吸附-解吸效果稳定；萃取-吸附工艺的 COD 总去除率达到99.8%以上，最大程度地实现了辛醇废碱液中有机物的回收。%Extraction and adsorption was adopted in sequence to remove the large amount of organics in the aldolisation spent caustic,wherein 2-ethyl hexanol was used as extractant which was then recovered by rectification,and HYA-106 macroporous resin was used for adsorption which showed stable adsorption-desorption performance. The results showed that under the conditions of pH=3,the volume ratio of 2-ethyl hexanol to spent caustic was 0.5 and the extraction stages was 2,ρ(COD) of the spent caustic could be decreased from 104651mg/L to 6453mg/L,while theρ(COD) removal rate reached over 93.8%. At 40℃,the adsorption rate of HYA-106 macroporous adsorption resin was 1BV/h,ρ(COD) of the extraction effluent was decreased to 155—183mg/L,whileρ(COD) removal rate was 97.1%—97.4%. The totalρ(COD) removal rate of the combined extraction and adsorption process reached more than 99.8%,showing the organics in the spent caustic was removed to a maximal extent.