Study on Further Treatment of Coal Coking Wastewater by Ultrasound Wave, Fenton´s Reagent and Coagulation

The study on further treatment of coal coking wastewater by ultrasound wave, Fenton´s reagent and coagulation was carried out in this paper at the first time, Furthermore, this paper discussed the optimum cooperative reaction condition of their combined application and the influence trend of COD by the single factor. The results showed that the removal rates of COD had optimum values with the variation of concentration of ferrous sulfate, the frequency of ultrasound, the concentration of FeCl₃, PAM and H₂O₂, these optimum value were 68.3%, 68.5%, 68.7%, 67.5%, respectively. As a result, it indicated that the best reaction conditions were C(Fe²⁺)=40 mg/L, C (H₂O₂)=55 mg/L, C (FeCl₃)=5.4 mg/L, C (PAM)=1.2 mg/L, and the frequency of ultrasound wave was 34.19 kHz, Under the reaction conditions, the removal efficiency of COD reached 77.7%. The influence sequence of the COD removal efficiency by the single factor was Fe²⁺> H₂O₂>PAM>the frequency of ultrasound wave > FeCl₃. This experimental result provides important reference foundation based on the choice of the treatment scheme of coal coking wastewater.