煤化工含酚废水高效萃取研究

Study on high efficiency extraction of phenolic-containing wastewater from coal chemical industry

针对煤化工含酚废水常用的MIBK、DIPE萃取剂对多元酚的萃取效率低等问题,开发出一种新型的酚类物质萃取剂-环己酮,对比了环己酮与MIBK、DIPE萃取效果,探讨了萃取相比、萃取温度、pH等主要影响因素,并进行了萃取剂回收试验。结果表明:环己酮对对苯二酚、间苯三酚的萃取效果分别高达91.65%、83.52%,远高于MIBK的74.05%、49.77%和DIPE的27.95%和7.84%;在温度40℃、相比1∶3、pH在8及以下的最优条件下,环己酮对苯酚、间甲酚、对苯二酚和间苯三酚4种典型的酚的萃取率分别为98.30%、96.83%、96.31%、91.67%;在最优条件下,对按不同配比的初始浓度分别为750mg/L、1000mg/L的混合配水进行环己酮萃取,单元酚和多元酚去除率分别高达97.81%、94.74%、96.96%、94.31%;在温度为155℃,常压下对混合废水萃取液进行蒸馏回收试验,环己酮的回收率可达95.5%以上。新型高效脱酚萃取剂环己酮的开发可以有效降低水中酚的浓度,减轻后续生化处理负担,为该类煤化工废水的处理与综合利用、行业的可持续发展提供技术参考。

Due to the problems of low extraction efficiency of polyphenols by MIBK and DIPE extractants commonly used in coal chemical phenol-containing wastewater,a new phenolic substance extractant-cyclohexanone was developed.The extraction effects of cyclohexanone and MIBK,DIPE were compared.The main influencing factors such as extraction ratio,extraction temperature,and pH were discussed,and the extractant recovery experiment was carried out.The results showed that the extraction effects of cyclohexanone on hydroquinone and phloroglucin were as high as 91.65% and 83.52% respectively,which were much higher than 74.05%,49.77% of MIBK and 27.95%, 7.84% of DIPE.Under the optimal conditions such as temperature of 40 ℃,extraction ratio of 1∶3,and pH value of 8,the extraction rate of cyclohexanone for four types typical phenol such as phenol,m-cresol,hydroquinone and phloroglucin were 98.30%, 96.83%,96.31%,and 91.67% respectively.Under the optimal conditions,the cyclohexanone extraction was carried out on mixed waters with different initial concentrations of 750 mg/L and 1 000 mg/L,and the removal rates of unit phenol and polyphenol were as high as respectively 97.81%,94.74%,96.96%,94.31%;The distillation of the mixed wastewater extract was carried out at a temperature of 155 ℃ and constant pressure,the results showed the recovery rate of cyclohexanone was over 95.5%.The development of the new high-efficiency dephenolization extractant cyclohexanone could effectively reduce the concentration of phenol in water and reduce the burden of subsequent biochemical treatment,providing a technical reference for the treatment and comprehensive utilization of such wastewater and the sustainable development of coal chemical industry.