Study On Catalytic Oxidative Degradation Of P-chlorophenol By NaClO Over Bimetallic Composite Catalysts

With social progress and industrial development,environmental pollution caused by sewage discharge is becoming more and more serious.Since the 18th National Congress of the Communist Party of China,the Party Central Committee has taken ecological civilization construction as an important part of coordinating the overall layout of the"five in one"and coordinating and promoting the"four comprehensive"strategic layout.The party's 19th National Congress emphasizes that"green water is the green hill."The important conclusion of Jinshan Yinshan shows that solving environmental problems has become an important factor affecting the healthy and stable development of China's social economy.The organic matter in the sewage is discharged into the natural ecosystem without treatment,which not only has a fatal impact on aquatic organisms,but also poses a great threat to the health of human drinking water.Therefore,it is urgent to propose an effective sewage treatment method.In this paper,a method for the preparation of bimetallic composite catalysts was carried out to simulate the wastewater treatment process.The conditions were optimized,the stability of the catalysts and a series of mechanisms were studied,and the degradation was carried out on a fixed bed scale.The test proves that the system has good degradation effect in phenolic wastewater,and provides a scientific and experimental basis for the practical application of wastewater treatment.In the third chapter of this paper,a quantitative CuO-MgO metal composite catalyst was prepared by co-precipitation method.After a series of characterization,4-chlorophenol was used as the standard substrate and NaClO was used as the oxidant for degradation experiments.In the experiment,the optimum conditions of the reaction system were determined by many factors such as temperature and pH of solution,the COD removal rate of 4-phenol reached 82%,and the substrate expansion experiment was used to expand the system.The scope of application proves that the system has good degradation effect on phenolic wastewater.The leaching rates of Cu²⁺and Mg²⁺are 0.01ppm and 0.03 ppm,respectively,indicating the stability and life of CuO-MgO metal composite catalyst.Good;finally,in order to study the degradation mechanism of CuO-MgO/NaClO catalytic oxidation system,four possible catalytic pathways were proposed,which were verified and eliminated one by one,and the O-Cl bond was uniformly cracked to form Cl·,which improved the theory of the whole degradation system..The fouth chapter of this paper is to prepare the supported composite metal oxide catalyst CuO-MgO@Al₂O₃ by rotary impregnation method,and set up a fixed bed device for the degradation test of phenolic wastewater,and explore the degradation effect of phenolic wastewater on a fixed bed.Simulate actual industrial wastewater treatment processes.The whole chapter mainly evaluates the catalytic oxidation degradation system of fixed bed based on catalyst loading,oxidant concentration,temperature and metal ion leaching rate.The experiment proves that under the condition of 45°C,residence time 1 h,catalyst loading,1 eq.of NaClO,the degradation rate of 4-chlorophenol in the fixed bed reached 92%and kept for more than 80%for a long time.The life of the ceramic supported catalyst is considerable.The ion leaching experiment shows that the catalyst has good stability and does not cause secondary pollution.The daily treatment capacity?20 h?can reach 4.8 L,which has a good application prospect in wastewater treatment.In summary,this system uses bimetallic composite catalyst to catalyze the oxidation of organic phenolic wastewater by sodium hypochlorite to obtain considerable degradation efficiency,which provides an important scientific basis for wastewater treatment technology.