Abstract:

Some shortcomings for the known techniques for coal-gasification wastewater treatment with high phenol concentration are low removal rate of phenols，high energy consumption，etc. A novel process was proposed based on the analysis of known pretreatment techniques. Two noticeable improvements were established in the proposed process to overcome the shortcomings. One is that CO₂ was absorbed by wastewater to reduce the pH value of the extraction unit to ensure high phenol removal performance，and the other was that extraction of phenols was the first unit in the pretreatment process. Some key operational parameters of the proposed process were analyzed and optimized though simulation. It was shown that desired purified water was obtained. The operating cost was significantly lower than that of some known techniques.