Study On The Degradation Of Phenol By Supported Cobalt Copper Catalyst And Cumg Catalyst In H₂O₂/HCO₃^- System

The development of industrialization and the rapid growth of population lead to excessive toxic substances into the environment, which directly affect people’s normal life and activities. Clean and safe water should be free from pollution, only in which way, human health and environment will not be influenced. In the past decades, environment pollution, especially the water pollution, is a serous problem, which also makes it an attractive research field. However, due to the complex chemical components and the difficulty to recycle, waste water treatment become one of the biggest challenges in the future. A lot of catalysts are applied to the water pollution control. Whereas, there are some problems of the catalysts, such as high leaching rate of metal ion、short life, which makes those catalysts hard to widely be applied to waste-water treatment. Hydrogen peroxide is clean、of rich resource and active as an oxidant, and bicarbonate is a weak alkaline buffer solvent, which is also widespread and non-toxic in nature. Bicarbonate activated hydrogen peroxide system is mainly concentrated on getting improvements both in stability and efficiency, which are considered the major difficulty in traditional treatment process. This paper will introduce a method, by combining heterogeneous catalysis system with the homogeneous system of bicarbonate activated hydrogen peroxide. The results shows that this system not only improves the stability of the catalyst but also provides further help for the development of the green, efficient and sustainable waste-water treatment.Phenolic compound pollution is harmful to aquatic and human life. Phenol is used as a model compound in waste-water to test the performance of catalysis system in degradation of waste water.In the second chapter, the work shows the degradation of phenol in bicarbonate activated hydrogen peroxide system with CoCu@y-Al₂O₃ supported catalyst which was prepared by step rotary impregnation method. Followed by optimizing a series of reaction conditions, and finally determine that the reaction conditions are at the calcination temperature of 500 ℃,10 mg of catalyst,50 mM H₂O₂,15 mM NaHCO₃, reaction temperature of 45 ℃, and after 1 h, eventually making 0.5 mM phenol degradation rate up to 90%, meanwhile the catalytic activity of catalyst in the degradation of phenol was illustrated by CODCr and TOC removal rate.The low leaching of mental ion was efficiently prevented for the presence of a weak basic media provided by bicarbonate and decreased the acid dissolution. Large numbers of chemical probes （radical scavenging experiments）, fluorescence capture experiments were conducted to identify the active species during the degradation process, which demonstrated that the process was based on producing free racial increased the degradation rates.In the third chapter, a series of copper supported catalysts were prepared by co-precipitation method and Cu@MgO catalyst was prepared by rotary impregnation method,which were used in the bicarbonate activated hydrogen peroxide system to study the performance of phenol’s degradation. CuMg catalyst shows the best catalytic activity under the same reaction conditions.We investigated the optimal reaction conditions in bicarbonate activation hydrogen peroxide system of phenol’s degradation（10 mg of catalyst, 30 mM H₂O₂,15 mM NaHCO₃, catalyst reaction temperature was 45 ℃）, after 1h reaction, which eventually giving 94.5% degradation of 0.5 mM phenol. The leaching of copper ion in the reaction system was just 0.27 ppm, which effectively improve the catalyst stability and service life. In this work, experiments were conducted in the radical scavenging, fluorescence and electron paramagnetic resonance experiments, the results show that the system is mainly produced by the active species of super oxygen free radical, That means it is active redox metal ions based degradation not hydroxyl free radical mechanism. By contrast, CuMgAl and CuAl catalyst system are based on the free radical degradation mechanism.Then a large number of electrochemical test were conducted, which provided more favourable clues for the catalytic oxidation of reducing.The results also show that take advantage of the catalyst’s crystal phase structure to control the formation of reactive species, which is more efficient and effective for the degradation of pollutants.