Coupling Adsorption-Photocatalytic Degradation of Methylene Blue and Maxilon Red

Abstract

The MB and MR removal process by two mechanisms of adsorption using rice straw (absence of UV light) and photodegradation on TiO2 surfaces was investigated. MB and MR removal efficiency were further intensified upon the sequential operation of adsorption followed by photocatalytic degradation over TiO2 under visible light irradiation. The TiO2 was used to remove methylene blue (MB) and Maxilon Red (MR) dye from aqueous media by continuous mode at 25 ± 2 °C, at pH 6.8 ± 0.2. Photo-illumination study revealed 75.81 and 65.51% MB and MR removal with the dose of 1 g/L TiO2 with an initial concentration of 5 mg/L within 120 min. This study can be deemed of potential applications for the removal of MB and MR dyes on an industrial level using the synergistic adsorption-photocatalytic oxidation approach. A probable photodegradation mechanism was proposed.