Modeling and optimization of simultaneous photocatalysis of three dyes on ceramic-coated TiO₂ nanoparticles using chemometrics methods: Phytotoxicological assessment during degradation process

In this paper, ceramic plates were used as a support of TiO₂ nanoparticles for photocatalytic decolorization of a mixture of three dyes. The three textile dyes (C.I. Basic Red 46, C.I. Basic Blue 3 and Malachite Green) were quantified simultaneously during the photocatalytic degradation process. The partial least squares modeling was successfully applied for the multivariate calibration of the spectrophotometric data. Also, the central composite design has been applied to the optimization of photocatalytic decolorization of the dye solution containing three dyes using an immobilized UV/TiO₂ process. The optimum initial concentration of three dyes, reaction time, and UV light intensity were found to be 5 mg/L, 240 min, and 47.2 W/m², respectively. The chronic phytotoxicity of mixture of dyes was evaluated using aquatic species Spirodela polyrhiza (S. polyrhiza) prior to and after photocatalysis. The phytotoxicity results revealed that the photocatalysis process could effectively reduce the phytotoxicity of the dyes from their aqueous solutions.