Photocatalytic degradation of textile dye C.I. reactive orange 16 in TiO2 water suspension by simulated solar light

Abstract

The photodegradation of C.I. Reactive Orange 16 (RO16), commonly used as a textile dye, was investigated using TiO2 as a catalyst and the sun lamp. The experiments showed that TiO2 and simulated solar light are necessary for the effective photodegradation, although a low degradation/adsorption was observed when only the simulated solar light or TiO2 was used. The effect of some parameters such as the initial concentration of the catalyst, the initial dye concentration, the initial Na2CO2 and NaCl concentrations, pH, and the presence of H2O2 on photodegradation of RO16 was examined. The photodegradation efficiency was highest at the catalyst concentration of 2.0 g/l. The degradation was faster in the acidic than in alkaline pH range. High adsorption of the dye was observed at low pH, while at high pH almost no adsorption was detected. A lower concentration of Na2CO2 decreased the photodegradation of RO16, while a higher concentration increased the photodegradation. The presence of NaCI led to the inhibition of the photodegradation process. The low concentration of H2P2 increased the RO16 photodegradation efficiency, while at higher concentration of H2O2 inhibition was observed.