Study On Treatment Technique Of Printing And Dyeing Wastewater By Catalytic Ozone Oxidation Of TiO₂/Fly Ash Supported Catalyst

Powder coal ash is one of China's major industrial solid waste,use powder coal ash as the catalyst carrier of catalytic ozone can produce more hydroxyl radicals,which can achieve the purpose of treating waste with waste,it contains a huge economic benefits and environmental benefits.The research with Huaneng Power Plant powder coal ash in Suzhou New District as the catalyst carrier prepared one of the optimum coal ash based catalyst,to catalytic ozone advanced treatment wastewater of Wujiang second printing and dyeing factory emissions to reach the level of reuse.First,the powder coal ash was modified;then,the optimal active component was found to load to the modified powder coal ash;finally,the best conditions for the preparation of the best catalyst were found by orthogonal experiments.The catalysts were characterized by SEM and BET,and the adsorption properties of powder coal ash based catalysts were studied.The effects of initial pH,catalyst dosage,reaction time and O3 volume fraction on the deep treatment of printing and dyeing wastewater were investigated,and the optimum treatment conditions were determined.Preliminary study on the reaction kinetics of catalytic ozonation and its reaction mechanism.Through the experimental study,the following 4 conclusions are drawn:?1?Powder coal ash by sulfuric acid modified effect best;TiO₂ / powder coal ash is determined as the best catalyst;preparation the optimum conditions for the best catalyst:active ingredient load is 1wt% and calcination temperature is 300?,the calcination time is2 hours,the immersion time is 15 hours.Known from catalysts characterized: the ratio of specific surface area for TiO₂ / powder coal ash is 78799cm²/g improved more than untreated powder coal ash of 9468cm²/g improves.?2?the factors analysis of printing and dyeing wastewater CODcr removal rate study shows: O3 output volume fraction > initial pH > catalyst quantity > reaction time;the optimized condition of single factor experiment and the orthogonal experiment for deep catalytic ozonation treatment of printing and dyeing wastewater were O3 output volume fraction is 40%,pH = 8.0?water solution PH?,the reaction time is 60 minutes,catalyst quantity 4 grams;effect on the removal rate of CODcr in the printing and dyeing wastewater,catalytic ozonation?75%?than ozonation alone?41%?has more advantages.?3?kinetic equation under the different factors of fitting,found that catalytic ozonation reaction are in line with the first-order kinetic equation,the activation energies of catalytic ozonation system and separate ozone oxidation system were measured,respectively12.36KJ/ml and 22.16KJ/ml,catalytic agent introduced to reduce the activation energy,increase the reaction rate.?4?o-phenanthroline-Fe???spectrophotometric analysis indirect determination of the concentration of OH radicals in catalytic ozonation system and ozone system were0.17mmol/L 0.22mmol/L respectively.The results show the introduction of catalyst can produce more OH radicals,result in stronger oxidative ability and improve the ability of waste water treatment.Compared to single ozonation the catalytic ozonation system has stronger tolerance on hydroxy radical inhibitor.