PHOTOCATALYTIC ACTIVITY OF POTASSIUM TITANATE REGARDING TO METHYLENE BLUE AND CONGO RED DYES

Abstract

The article deals with the photocatalytic activity of potassium titanate obtained by the alkaline melting method of Ilmenite of Irshansk deposit (Ukraine) regarding different dyes: methylene blue, which belongs to the cationic type, and Congo red, which is an anionic dye. Photocatalytic agents are used to degrade organic pollutants in aqueous environments using light. Photocatalytic degradation of dyes is one of the modern and promising methods for wastewater treatment. This method of photocatalytic dye degradation offers several advantages, including high speed and process efficiency, simple and inexpensive equipment, and a small mass of photocatalyst, among others. In this study, potassium titanate was used as a catalyst for the photocatalytic degradation process of methylene blue and Congo red dyes in solutions. The photocatalysis was conducted using a 40 W UV lamp (λ = 365–400 nm) with constant stirring (catalyst mass – 5 mg, dye solution volume – 20 ml) at a temperature of 293 K. After reaching equilibrium, the catalyst was separated from the solution by centrifugation at a rotation speed of 1500 rpm for 5 minutes. The dye concentration before and after the photocatalytic degradation process was determined using a UV-1200 spectrophotometer. The article analyzes and defines the time and concentration dependencies of the photocatalytic degradation process of methylene blue and Congo red dyes on the surface of potassium titanate. The degree of dye photocatalytic degradation (X,%) was calculated based on the changes in concentration before and after ultraviolet irradiation of the solutions. This research describes that the photocatalytic activity of potassium titanate depends on the dye concentration in the solution and the irradiation time. It was established that with a 10-minute ultraviolet irradiation of the catalyst-solution reaction mixture under constant stirring, at the maximum concentration of methylene blue (10 mg/L), the degree of dye photocatalytic degradation was 81.91%. The paper shows that potassium titanate has no significant effect on the photocatalytic degradation of Congo red compared to methylene blue, which can be explained by the different molecular structures of the dyes.