Study On Treatment Technique Of Dyeing Wastewater By Catalytic Ozone Oxidation Of Fly Ash Supported Catalyst

This study has been used fly ash from the WangTing Power plant of SuZhou as thecatalyst carrier, have been prepared the best fly ash supported catalysts, which was appliedthe advanced treatment to the secondary biological effluent treated by A/O process fromXinDa Printing and Dyeing factory. The fly ash is a kind of solid waste, with treatment thewaste water, to achieve the purpose of waste treat waste.Firstly, searching for the right modification methods of fly ash modification; secondly,looking for the best of the active component with the carrier, preparation the best catalyst;to determine the best condition of preparation with orthogonal test. To study the adsorptionperformance of fly ash supported catalysts, and the catalysts have been described by XRDand BET. Examine the amount of catalyst dosage, pH value, reaction time, O₃dosingquantity of factors as the depth of the influence of printing and dyeing wastewatertreatment, and find to the optimum conditions of catalyst preparation. Study of catalyticozone oxidation reaction dynamics, and probe into the reaction mechanism.Through a series of experiments, the results were showed as follows:（1） The best modification methods of the fly ash is acid modified. Experiments showedthat the best effect catalyst was NiO/Fly ash. Prepared by orthogonal experiment, theoptimum conditions of preparation catalyst are: load capacity of1wt%, dipping time was15h, calcination temperature of300℃, calcination time was2h. Through thecharacterization of catalyst, it can be seen the NiO has been highly uniform scattered loadsto the carrier surface. The surface erae increases from9458cm²/g to78697cm²/g withNiO/fly ash.（2） Orthogonal array experiments were designed to study the different degree of impacton the treatment effection. The result was: O₃volume fraction> pH> catalyst dosage>reaction time. It is found by single-factor experiments that the best experimental conditionsare as follows: O3volume fraction is40%of output （mass concentration is9.22mg/L）,catalyst dosage is4g/500mL, pH is6.5, reaction time is60min. In this condition, the CODremoval rate from the separate ozone oxidation41.44%increased to73.87%, chromaremoval rate can reach to98%.（3） Through the try method, in different ozone concentration, different pH value,different amount of catalyst, different reactants initial concentration conditions catalyticozone oxidation reaction which are conform to the level1reaction kinetics model.（4） The activation energy is22.06KJ/mol of the ozone system, in the catalytic ozone system the activation energy is12.06KJ/mol. It explains introduction of the catalytic caneffectively reduce the activation energy, enhance the reaction rate.（5） Through the determination of hydroxyl radicals concentration, the·OH concentrationis0.164mmol/l of the ozone system; the·OH concentration is0.216mmol/l of the catalyticozone system. Introduction of the catalyst can promote ozone decomposition produce moreof the hydroxyl freedom, to improve the reaction system in the processing power.