煤气化高浓度含酚废水萃取/反萃取脱酚技术研究

Study on extracting/reverse extracting dephenol of gasified high-concentration phenol-containing wastewater

为实现煤气化高浓度含酚废水的资源化利用,通过研究不同萃取剂浓度、温度、pH值和萃取比(萃取剂与含酚废水的体积比)对萃取脱酚效率的影响,建立了磷酸三丁酯(TBP)-煤油溶液做萃取剂的萃取体系;通过研究NaOH溶液浓度和反萃取比(反萃取剂与含酚废水的体积比)对反萃取回收酚类效果的影响,建立了NaOH反萃取回收酚类的方法体系,并对萃取剂的重复使用进行了实验。结果表明,萃取脱酚率大于97.0%,反萃取脱酚率达93.4%,总的回收酚率达90.0%,且废水经过萃取反萃取脱酚后出水质量浓度由2259.8mg.L-1降到75mg.L-1以下。实验表明30%TBP-煤油溶液是一种可以长期循环使用的工业萃取剂;30%TBP-煤油溶液和NaOH反萃取体系可以成功的回收煤气化高浓度含酚废水中的酚,从而有效的减轻废水后续处理的负担。

In order to realize the recycle of gasified high-concentration phenol-containing wastewater, experiments were carried out to find out the extracting effects of the system with different concentrations, pH, temperature and solvent ratio （the vohtme of extracting solvent to wastewater）, and an extracting system using 30% TBP-kerosene solution as an extracting agent was set up. Experiments were carried out to find out the reverse extracting effects of different NaOH solution concentrations and solvent ratios （the volume of extracting solvent to wastewater）, and a reverse extracting system using NaOH solution as reverse extracting agent was set up. The experiments for reusing the extractant were performed. The results showed that the rate of dephenolization was higher than 97.0%, the recovery rate of phenol was 93.4%, the total recovery rate of phenol was about 90.0%, and the phenol in wastewater after extracting can be reduced from 2 259.8 mg· L^- 1 to less than 75 mg·L^-1. The experiments also showed that the 30% TBP- kerosene was a good industrial extractant that could be reused reusing several times. The 30% TBP- kerosene and the NaOH solution system could success recycle phenol of high-concentration phenol-containing wastewater, which could reduce the burden for the following processing.