Dye removal from waters by rare earth ion doped TiO2 immobilized on porous glass

In advanced oxidation processes, heterogeneous photocatalytic processes can effectively remove different types of pollutants at ambient temperature and pressure, without producing harmful intermediates. TiO2 is the most widely used semiconductor in photocatalysis studies. The disadvantage of the TiO2 photocatalyst, which has many advantages over other semiconductor materials, is that it is very difficult and costly to separate the powder dispersions from the water after treatment. Its release into the environment leads to deterioration of human health and ecology. For this reason, the use of TiO2 photocatalyst by fixing it on a support layer and making it active in daylight by doping with metallic/non-metallic elements by various methods is one of the subjects that have attracted great interest in recent years. In this study, a photocatalyst that can be easily separated from water and activated under visible light was produced by coating Nd-doped TiO2 on a porous glass support material. With this material, the removal of reactive red-195 dyestuff by the adsorption-photocatalysis process in different ambient conditions from the aquatic environment was investigated using the Taguchi experimental design, and the results were evaluated with ANOVA. The highest dye removal was obtained as 83% for the initial pH value of 3.5, dyestuff concentration of 10 mg/L, amount of photocatalyst 0.2 g/L, under 9 W and 18 W visible light irradiation for 30 minutes. The effect of ambient conditions on dyestuff removal was obtained as 53.76%, 14.27%, 11.80%, 11.73% and 1.18% for initial pH, reaction time, photocatalyst dose, initial dye concentration and light intensity, respectively. According to the ANOVA results, P values were statistically significant for all other variables except light intensity. The R2 value for the created model was 92.73% and the adjusted R2 value was 88.19%.