Study on the treatment of spraying wastewater from coal-fired flue gas by using discharge free radicals

The coal-fired flue gas spraying wastewater is a kind of refractory mixed wastewater with poor biodegradability. In this study, the degradation of model coal-fired flue gas spraying wastewater was studied by using discharge free radicals produced by double-dielectric barrier discharge. The degradation rate of pollutants, chemical oxygen demand removal rate and other indicators were detected, and the influence of different conditions on the degradation effect was analyzed. The optimal parameters are as follows: residence time 120 min, input power 170.0 W, initial pH value 3.79, and aeration rate 1.8 mL/min. The initial concentrations of acetone, formaldehyde, chloroform, benzene and toluene were 100, 100, 100, and 100 mg/L, respectively. Furthermore, it is proved that the discharge area is independent of the degradation rate. Through the analysis of the mechanism, it is found that ·OH is an important factor affecting the degradation rate of pollutants in model coal-fired flue gas spraying wastewater.