Treatment Of Paper Making Wastewater With Coagulation And Fenton Oxidation And Flocculation Proess

In this paper, the merit and demerit of currently domestic and foreign technics used to treat paper making wastewater is summarized on the basis of fully understanding the process of paper making industry and the characteristics of paper making wastewater. Furthermore the progress trend of these technics and the mechanism of coagulation sedimentation and Fenton oxidation are analysed.In this research, the coagulation sedimentation is firstly used to treat the paper making mixed wastewater. Then Fenton oxidation is used. Lastly the wastewater is treated by coagulation again. Firstly, orthogonal experiments are used to determine the main factors of different processing units. Then single-factor rotates are used to research how every factor effect the results of the experiments and to get relationship curves of the factor and the results of the experiments (the removal efficiency of COD or chroma) to determine the best values of the factors.In the research, the effects of coagulant type, coagulant dosage, pH, assistant coagulant dosage on the result of pre-coagulation treatment are inspected; And the effects of H2O2 dosage, temperature, pH, nFe2+/nH2O2, reaction time and other factors on the Fenton reagents oxidation treatment result are inspected; Finally inspected the effects of pH, coagulant type and coagulant dosage on the later coagulation treatment are inspected. Through the experiments, the paper making wastewater treatment process is identified. And the optimum operating conditions are also determined. The identified treatment process is a three-step process, including pre-coagulation treatment, Fenton reagents oxidation and later coagulation sedimentation. The optimum operating conditions for the pre-coagulation treatment is that the reacting temperature is at the normal atmosphere temperature, the dosage of PAC is 15ml/L and PAM 5ml/L,pH is 3,total distribution time is in 18 min around, and then 20min for sedimentation. The optimum operating conditions for Fenton reagents oxidation is that the dosage of H2O2 is 15 mL/L, the reacting temperature is at 20 degrees (normal atmosphere temperature), the pH is 3,...