Photocatalytic degradation of reactive dyes and real textile composite wastewater using TiO2/MWCNT nanocomposite under UVA and UVA-LED irradiation. A comparative study

Abstract

Nano TiO2 and TiO2/MWCNT nanocomposite synthesized by the sol-gel method were characterized by XRD, BET, SEM, EDAX and FTIR techniques. These nanoparticles were used for photocatalytic decolorisation and degradation of three different reactive dyes such as Reactive Orange 16 (RO 16), Reactive Yellow 145 (RY 145) and Reactive Red 195 (RR 195) and real textile composite wastewater under the UVA and UVA-LED irradiation at room temperature. The maximum color removal of 96% and COD removal of 72% were achieved after 5 h in the presence of TiO2/MWCNT and H2O2 under UVA-LED irradiation. The kinetic studies obey pseudo-first order kinetics which is discussed in terms of the Langmuir–Hinshelwood kinetic model. The maximum degradation of 50% was achieved after 5 h in the presence of H2O2 using TiO2/MWCNT/UVA-LED for real textile composite wastewater. This study revealed that TiO2/MWCNT has improved the photocatalytic activity when compared to that of bare TiO2 under similar conditions. UVA-LED could be an alternative light source for the replacement of the conventional UV light for the photocatalytic treatment of reactive dyes.