Study Of Coupled Oxidation And Flocculation Process In Treating Dye Wastewater

To solve the problem that dye wastewater was difficult to be treated, two kinds of coupled flocculation and oxidation process had been put forward in this paper. One of which was potassium permanganate/poly-silicic-ferric sulfate(PFSS)coupled flocculation and oxidation process, the other was H₂O₂/poly-silicic-ferrous sulfate ( PFSSâ…¡) Fenton-like coupled flocculation and oxidation process.Permanganate/PFSS coupled flocculation and oxidation process has been used in treating acid brilliant scarlet dye wastewater. When the reaction time of oxidation stage was 10 min, n(Fe)/n(Si) of PFSS was 1∶3, dosage of potassium permanganate and PFSS was 20mg/L and 15mg/L, the decoloration rate of acid brilliant scarlet was over 94%. The reaction mechanism has been analyzed through electron-microscope photos of aggregates morphology, Zeta potential on the surface of acid brilliant scarlet, UV-Vis Adsorption Spectrum and Infrared Adsorption Spectrum. Acid brilliant scarlet dye wastewater is treated by Permanganate/PFSS coupled flocculation and oxidation process in continuous flow condition. The color and COD removal rates reach 94.9% and 55.2%.H₂O₂/PFSSâ…¡Fenton-like coupled flocculation and oxidation process had been used in treating of reactive brilliant red dye wastewater. At the conditions of n(Fe)/n(Si) of PFSSâ…¡was 1∶3, dosages of H₂O₂ and PFSSâ…¡respectivily were 10mg/L and 15mg/L, reaction time of oxidation stage was 30 min, the decoloration rate of reactive brilliant red was over 98%. The reaction mechanism had been analyzed through discussion of oxidation kinetics, UV-vis adsorption spectrum and infrared adsorption spectrum. Dye intermediate wastewater is treated by H₂O₂/PFSSâ…¡Fenton-like coupled flocculation and oxidation process in continuous flow condition. The color, COD and turbid removal rates reach 100%, 94.8% and 94.6%.It shows that good results can be achieved by using of these two kinds of coupled flocculation and oxidation process in treating dye wastewater, and the cost is cheap. Results of expriments in continuous flow conditions also prove that both methods have great practicability.