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Study On Treatment Of Refractory Wastewater By Hydrogen Peroxide Catalytic Wet Oxidation

Posted on:2006-06-01Degree:MasterType:Thesis
Country:ChinaCandidate:J M DongFull Text:PDF
GTID:2121360182470086Subject:Environmental Engineering
Abstract/Summary:PDF Full Text Request
Wet Air Oxidation (WAO) is a method that treats effectively high density organic wastewater of poisonous harmfulness and difficult degradation . But since its requirement goes on under the high pressure and high temperature, just, catalyst is valuable and noble metal series, difficult preparation mostly , easily to run off , its cost highly. That makes it to get restriction in actual application. Therefore, developplng efficient and economic reasonable invaluable metal series catalyst , reducing reaction temperature and pressure as far as possible, reaching normal temperature and pressure to go on with the experiments, will have significant meanings for wet air oxidation in popularizing and applications. In view of this, author passes through to look up informations and researches for transitional metal oxides of Mn , Cu , Ce , Sn , Ag , Bi , Fe , Zn , Co , Ti and so on , has carried out extensive experiments and explores , developping some loaded and immobilized catalysts with main four components and hydrogen peroxide as oxidant , at normal temperature and pressure , as treating high density organic wastewater with Catalytic Wet Hydrogen Peroxide Oxidation (abbreviatively calling CWHPO) , the comparely satisfactory results can be reached by the little scales tests of laboratory. The efficiencies of different catalysts show that four-components catalysts of MnO2-CuO-CeO2-ZnO(mole ratio is 2:4:2:1)or MnO2-CuO-CeO2-Fe2O3 or MnO2-CuO-CeO2-CoO were the better ones .When the condition of reaction was general temperature and pressure , maintaining weak acidity scopes of pH value, and reaction time was 40~60 min, the COD removals rate and decolorization rate were over 80% and 90% . It can comparely reach the satisfactional handling effects. Moreover, this paper has established a reaction kinetic model involving liquid and solid phases in the research under the condition of general temperature and pressure. The industrial wastewater containing high concentration organic compounds was treated by the method of Catalytic Wet Peroxide Oxidation process(CWHPO). When the reaction time was 40~60 minutes,the concentration of COD in the treated wastewater could drop from 1000mg / L to lower than 100mg /L. For the multiphase catalytic oxide-reaction process,taking COD as the target removal pollutants, in the experiments of the main affecting factors on the performance of purifying COD in wastewater, such as the reaction time, concentration of COD, demands of oxidants , a vast research had been taken among these main factors . The result is that a good suitability of the kinetic model for practical process was verified. The interrelation coefficients(R)between calculated data and experimental data were more than 0.92 . The kinetic model is more suitable for research of removing high concentration COD from the wastewater to be treated in the process of CWHPO . To introducing the technology of catalytic wet oxidation hydrogen peroxide at the same time, this paper also discusses the possibility that this kind of technology is used in actual wastewater treatment, from the economic reasonable and technical maturation such as many other aspects, and discusses the economic technical index of this kind of method. For pointing out the extant problems of good advantage and shortcoming of this kind of treating technique, it summarizes the roles and positions of catalytic wet oxidation method in wastewater pretreatment near ten years, and explores the major problems of developing toward some direction in this fields, and solves the major problems in need of great efforts in the future .
Keywords/Search Tags:Catalytic wet hydrogen peroxide oxidation(CWHPO), the loaded and immobilized type catalysts of composited-compound oxides, the difficult degradation high density organic wastewater, Reaction dynamics equation, the macerating and precipitation methods
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