Treatment of synthetic dyes wastewater utilizing a magnetically separable photocatalyst (TiO2/SiO2/Fe3O4): Parametric and kinetic studies

The TiO2/SiO2/Fe3O4 (TSF) photocatalyst was used for the treatment of synthetic dyes wastewater. Different operating conditions such as catalyst load, pH and dye concentration were investigated in order to determine the optimum operating conditions. The optimum operating conditions were found to be 2500 ppm TiO2 photocatalyst dose and pH 3. More catalyst dose led to reduction in rate of reaction due to aggregation of photocatalyst as well as increasing of opacity inside photoreactor. Acidic medium favored adsorption of studied dyes on photocatalyst, and hence increased the rate of reaction. Under optimum conditions, complete decolourization and degradation of the organic dyes could be achieved within less than 45 min. Kinetic studies indicated that rate of reaction depends on three parameters: photocatalyst load, dye concentration and transmittance inside photoreactor. TSF photocatalyst could be used several times with nearly the same efficiency. The reuse of the photocatalyst is supposed to decrease the final cost of the treatment process.