Experimental Study For SCWO Treatment Of Volatile Phenol In Coking Wastewater

There are many kinds of volatile phenol in coking wastewater produced by oil industry, coal washing industry, coking industry and so on. They are very poisonous and polluting to surface water and groundwater, affect the growth and breeding of animals, plants and aquatic organisms. Because the phenol in the waste water has a high concentration and complicated composition, coking waste water is difficult to be processed. Nowadays, the topic of concern in the environmental protection field is how to increase the degradation rate of volatile phenol.At the present stage, in the respect of treatment of high phenol concentration wastewater, physical-chemical process and Biological method process are the two kinds of commonly used methods. But they are complicated, the fluidity of the water quality affects treatment effect a lot, and the processes pollute the soil and water, the cost of economic and technology is high. The above reasons can’t meet the high requirements of discharge. So the new method-SCWO becomes hot topic technology. The advantages of SCWO are processing speedily, efficiently, low secondary pollution and so on. So SCWO is the ideal method to degradation organic.In this study, simplified SCWO experiment device was used to research the degradation of volatile phenol in coking wastewater. Experimental conditions are:the antioxidant is H2O2, the temperature is from380℃to500℃, the pressure is from23MPa to28MPa, the oxidant excess multiple is from1to3, the reaction time is from36seconds to60seconds. Every influencing factor was divided into several parts for different this experiment to observe the regular pattern from the degradation of volatile phenol (calculate phenol). The results showed:all these four factors were positive. Then orthogonal experiment was on, we knew the primary and secondary order was:reaction time> oxidant excess multiple>temperature>pressure, and the best combination was:45seconds,1multiple,480℃and28MPa. But every concentration of effluent was lower than emission standards at the first national level and out of the rigorous reaction conditions, catalysts were used into the experiment to relieve the high requirements. In this study, the catalysts are CUSO4and MnO2. The results showed these two both had good catalytic effect, but CuSO4is better than MnO2. We had when CUSO4was the catalyst and H2O2was the oxidant, the best experimental condition combination was3multiple,40seconds,440℃and24MPa. Cost issue of SCWO was analyzed, and it proved SCWO was economically viable.SCWO is, so far, the most potential for development of wastewater treatment technology, but in the future, there are many problems to solve, such as corrosion, salt deposition heat recovery and so on.