Photodegradation of dye in the presence of metal ions using composite as catalyst

Advanced oxidation processes such as photocatalysis have been shown to be very robust in the removal of biorecalcitrant compounds. In this work, photocatalytic degradation of synthetic textile wastewater (methyl orange dye) in the presence of Cr(VI) was carried out using TiO₂ supported onto silica. A composite of TiO₂ and silica was prepared, analyzed and applied in a batch photoreactor. The composite photocatalyst was characterized by Scanning Electron Microscopy and Energy Dispersive Spectroscopy (SEM-EDS) and Raman spectroscopy (RS). Operating parameters such as composite photocatalyst loading, initial dye concentration and pH were determined. The performance of the photocatalyst reactor was evaluated on the basis of color removal and metal ion reduction. The reduction of Cr(VI) to Cr(III) was improved in the presence of the dye. The results revealed the potential of the composite photocatalyst to treat mixed wastewater containing heavy metals like Cr(VI).