Thermal degradation characteristics of contaminants in wastewater from coal gasification process

Considering the problems of high toxicity and intractable thermal degradation of gasification wastewater, a novel approach was proposed based on pyrolysis and combustion. In an entrained flow reactor system, the effects of temperature, atmosphere, oxygen concentration and residence time on the thermal degradation characteristics of contaminants in wastewater were investigated. The analysis results show that temperature is the most sigificant factor in COD and NH₃-N thermal degradation, and the maximum degrading rates is within the range of 400℃ to 600℃. COD and NH₃-N thermal degradation rankings under different atmospheres are as follows: oxidative>inert>reductive. As the oxygen concentraiton increases, the thermal degradation effi-ciency is improved. The longer wastewater remains in the reactor, the better the effect of contaminants removal will be.