Comparative studies of degradation of dye intermediate (H-acid) using TiO2/UV/H2O2 and Photo-Fenton process

The present work is focused on the homogeneous and heterogeneous photo-catalytic degradation of Hacid, a non-biodegradable dye intermediate from dye manufacturing industries, using Advanced Oxidation Processes (AOPs) such as UV, UV/H2O2, UV/H2O2/Fe 2+ (photo-Fenton process), UV/TiO2 and UV/H2O2/TiO2. Degradation experiments were carried out to optimize the amount of catalyst, effect of Hacid concentration, contact time, effect of pH on chemical oxygen demand (COD) etc., using UV-visible spectrophotometer, and further analysed with High Performance Liquid Chromatography (HPLC) technique. The nano catalyst was characterized with Fourier Transform Infrared (FTIR) and Scanning Electron Microscopy (SEM). The degradation rate was strongly influenced by the pH, initial concentrations of H2O2 and catalyst. The maximum degradation of was achieved at pH 3 to 4 in all AOPs experiments. The optimum H2O2 concentration is 300 mg/L achieved with heterogeneous AOPs as well as homogeneous AOPs in maximum of 90 min reaction time. The Maximum 84% degradation achieved with TiO2/UV/H2O2. The order of COD reduction is UV/H2O2/TiO2 > photo-Fenton > UV/TiO2 > UV/H2O2 > UV.