Research on Photocatalysts Based on Fly Ash Cenospheres from CHP Plants Used for Purifying Water from Organic Pollutants

This article examines the results of a research on photocatalysts based on fly ash cenospheres from CHP plants used when purifying water from organic pollutants. The goal of the work is to obtain photocatalysts based on fly ash cenospheres from CHP plants, for water purification from organic compounds. Structural and chemical parameters of cenospheres have been studied. It has been determined that cenospheres are highly porous materials with a low density of 0.7 kg/m3. Under the influence of mechanical stress, destruction of cenospheres occurs along the least durable elements—internal pores. The thickness of the outer shell of the spheres ranges from 5.6 to 14.4 microns. The destruction of the walls of the spheres is complicated by defects of closed pores in their structure, which increase the path of the main crack. With a mass of cenospheres in an aqueous solution 4 times less than generally accepted concentrations, high effectiveness of the photocatalytic coating was achieved in the decomposition of the methylene blue redox indicator. The obtained experimental data show that the photocatalytic coating on cenospheres reduces the concentration of methylene blue by 25% within two hours of irradiation. The photocatalytic activity of cenospheres towards cyclic hydrocarbons has been assessed using the example of the destruction of phenol. It has been determined that the presence of cenospheres on the water surface significantly increases the rate of phenol destruction during photocatalytic oxidation.