Research On Dyeing Wastewater Treatment By Zeolite Heterogeneous Catalytic Ozonation

Dyeing wastewater was a difficult disposed effluent, which has high CODcr, bright color, diverse alkalescence and pH, molecular stability, so traditional wastewater treatment methods could not work well with dyeing wastewater. It was suggested in this paper that ozonation and catalytic ozonation processes be applied to treat the dyeing wastewater with simulated wastewater,actual wastewater and self-regulating device.In the study of ozonation Direct Blended YellowD-3RNL alone, primary researches had detecting the color, UV adsorption, CODCr, TOC, pH value and UV-VIS adsorption of the effluent. It was known that at the end of ozonation, CODCr removal rate and TOC removal rate were 52.86% and 22.85%. The pH value in the reacting system was also found to decrease from 8.30 to 3.06. The efficiency of ozone oxidation dye wastewater is not high.Ozone oxidation degradation should be further enhanced, so the test studied heterogeneous zeolite catalyst carrier and catalytic oxidation effect. In heterogeneous catalytic ozonation, all catalysts with MnO2/zeolite, Fe2O3/zeolite, ZnO/zeolite and CuO/zeolite were prepared using impregnation method, with zeolite as their supports. The results showed that MnO2/zeolite> Fe2O3/zeolite>ZnO/zeolite> CuO/zeolite. Meanwhile, repetitive utilization rate of MnO2/zeolite is high, CODCr removal would reach 75.67% to 79.28%. It can be seen that effect of catalytic ozonation with zeolite as the support was better than that of activated carbon.It was studied that two-component catalyst with zeolite carrier follow the research of heterogeneous catalyzer. Investigations showed that the catalytic effects were deeply influenced by the catalyst preparation conditions. The optimal preparation conditions were that catalyst components MnO2-Fe2O3, soaking time 18h, calcinating temperature 450℃, calcinating time12 h, and Mn-Fe chroma ratio 2:1, respectively. The third component of the ozone oxidation catalyst for dyestuff wastewater treatment was also researched. The results showed that the best three-component catalyst was Mn-Fe-K(2:1:1)/zeolite.The experimental studied that catalytic ozonation treated with actual dyestuff wastewater with catalyst Mn-Fe-K(2:1:1)/zeolite, and its treatment efficiency was obviously superior to ozone oxidation process. Consequently, catalyst Mn-Fe-K(2:1:1)/zeolite had better effect for treating with actual wastewater, and catalyst with zeolite carrier had high practical value.