Advanced treatment of biochemical effluent from printing and dyeing wastewater by chemical oxidation
Three oxidation systems:Fenton+coagulation,ultraviolet(UV)/H2O2 and ozone+coagulation,were used for advanced treatment of secondary sedimentation tank effluent of printing and dyeing wastewater,and the treatment effect was quantitatively analyzed.The results showed that,the above three oxidation systems could reduce the mass concentration of COD in secondary sedimentation tank effluent to below 30 mg/L,and the wastewater treatment cost of Fenton+coagulation was the lowest,which was 3.25 yuan/t.UV/H2O2 had the strongest pollutant-removing ability,the mass concentrations of COD and TOC were 19.9 and 2 mg/L respective-ly.ozone+coagulation obtained the best colority-removing effect,and the colority of the effluent water was only 5.6 degree.According to the comprehensive consideration,Fenton+coagulation system was more suitable for the said kind of wastewater treatment.