Study On Depth Treatment For Paper Wastewater By Fenton Fluidized-bed And Coagulation Sedimentation

Nowadays we mainly adopt mature physicochemical plus biochemical process to deal with paper wastewater. However, it is more and more difficult for effluent to meet the requirement of the increasingly pollution emission standards, looking for the effective and economically viable ways are necessary. In this paper, “Fenton fluidized-bed plus coagulation-sedimentation” combined process was used for treatment depth study of paper wastewater, which was collected by mixed paper wastewater treatment plant of Xinmi from sewage plant of paper companies around. Source of paper wastewater and necessity of advanced treatment had been elaborated, the advancement in depth treatment had also been introduced.The first was dealing with mixed paper wastewater by Fenton fluidized-bed. By means of single factor experiment and response surface methodology, the result showed that significant relationship between the influencing factors was: the influent p H value>dosage of H2O2>carrier fill rate>[H2O2] /[Fe2+] mole ratio>reaction time. Two-order polynomial equation had been obtained between the COD removal efficiency and influence factors by Box-Behnken design,the correlation coefficient square was 0.937,which represented that the fitting model’s precision was high. After analysing and optimizing the experimental data base,the theoretical result of optimal operating conditions was conformed: the influent p H value was 3.6, dosage of H2O2 was 1.52 ml/L, carrier fill rate was 28.8%, [H2O2] /[Fe2+] mole ratio was 4.86, and reaction time was 58 min. Prediction of COD removal rate was 74.8% on this operation condition. Through several times of repeated experiments, the actual COD removal rate was 72.4%, and the relative deviation was 3.14%,which indicated response surface analysis to optimize operating conditions and COD removal efficiency of prediction were both accurate. At last, the result got from these contrasted trials showed that COD removal efficiency of Fenton fluidized-bed was 15.8% higher than traditional Fenton reaction after adding quartz sand carrier which loaded iron oxide.Then through making coagulation sedimentation experiment on the effluent of Fenton fluidized-bed reactor, the results showed that when the influent p H value was 7.0 and dosage of 0.1% PAM was 1.2 ml/L, COD removal efficiency and chromaticity removal efficiency were separately 21.5% and 69.3%.This paper research not only has a certain theoretical guidance to the practical engineering construction, but also provides technical reference for industrial wastewater deep treatment process selection.