| Refractory organics refer to compounds which have difficulty in being decomposed and accumulating rapid degradation. Traditional processing methods include physical method,physical-chemical process, chemistry processes,and biological treatment method. Meanwhile chemistry processes especially Fenton process and photocatalysis of TiO2 became a research focus. However,fenton method may consume large amounts of hydrogen peroxide and the catalyst cannot be separated and reused. The need for additional UV devices for photocatalytic treatment increases the cost of processing, which limits the application of photocatalysis in industry. It has great significance to design a catalyst with high catalytic performance,easy recycling.In our study, the common dye wastewater was chosen as the research object, and compared with the traditional system of degradation. Firstly, the water soluble phthalocyanine catalysts were synthesized by high temperature melting, and the degradation efficiency was evaluated.In the absence of additional illumination, temperature and pressure conditions, the use of molecular oxygen catalytic oxidation of methylene blue solution, analysis of the factors influencing the catalytic efficiency and to explore the optimal experimental conditions. The change of absorbance at the maximum absorption wavelength of methylene blue solution was determined. The content of total organic carbon was determined by the national standard method. The effects of light and air injection on the catalytic degradation were studied. The maximum degradation rate of methylene blue was 40% when the light was added into the air and the cobalt phthalocyanine catalyst was added to the catalyst with the addition of four carboxyl groups. When the photo catalyst is added into the air, the methylene blue is not degraded, which indicates that the catalytic reaction generates reactive oxygen species.Subsequently, the preparation of Fe3O4 magnetic particles by conventional coprecipitation method was improved. In the first attempt, chitosan solution was mixed with ferric salt, and then mixed with precipitation agent to form the magnetic powder coated with chitosan. The magnetic properties and particle size of the particles were controlled by adjusting pH and temperature. The micron sized chitosan particles have good magnetic properties and good dispersibility, and have regular spherical morphology, and the particle size is between 1-3 ?m. At 80 ?, the speed of 650rpm, in the case of nitrogen protection by adding ammonia to pH=10, the magnetic particles are the most magnetic. Magnetic chitosan particles have amino and hydroxyl functional groups, which can be used as carrier of the particles.Finally, the degradation of methylene. blue and eosin was studied by using the catalyst. The results show that the supported catalyst has high catalytic activity for methylene blue and eosin, which shows the advantages of heterogeneous catalysts. The use of fluorescent lamp at room temperature under the irradiation of supported phthalocyanine catalyst and methylene blue aqueous solution reaction for 6 hours, the degradation rate of methylene blue reached 99%, the total organic carbon content was decreased by 88%, and the degradation rate of the phthalocyanine catalyst without load can only reach 41%. Moreover, the catalyst can be separated into the same concentration of methylene blue by using the external magnetic field separation. After 4 cycles of reaction, the degradation efficiency of the catalyst has not changed much, and only decreased from 99.2% to 90.2%. Phthalocyanine catalysts supported on the degradation of eosin showed a higher degradation rate, when the sun light irradiation,pH=2, air condition, eosin reaction for 4 hours, the degradation rate reaches 99.8%, the total organic carbon was decreased by 80%. The phthalocyanine catalyst can be separated and recycled by the external magnetic field, so it has a good application in the actual industrial production wastewater. |
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