Degradation of Thiazine Dyes Azure B and C by Sonolysis, Sonophotolysis and Sonocatalysis

摘要

The present research focuses on the application of advanced oxidation processes as sonolysis (US), sonophotolysis (USAJV) and sonocatalysis (US/O3) for the degradation of thiazine dyes (Azure B and C) in aqueous solution. In this study, the concentration, temperature, pH, light intensity and gas flow rate on the dye decomposition were examined to find the optimum operating conditions of the treatment processes. Complete degradation was achieved in the relatively short time at 60 min irradiation. Faster decolourization was achieved at high pH and temperature. The degradation with sonocatalysis (US/O3) was fastest. The best results were obtained from sonocatalysis (US/O3) with efficiency more than 98 % of Azure B in comparison with Azure C 97 % at gas flow rate = 1.5 L/min and 0.025 g/min. The activation energy for both Azure dyes studied were decrease with temperature increase between 288-308 K. The decolourization of the dyes followed first order kinetics. Also both techniques sonophotolysis (US/UV/O3) and photo oxidation (UV/O3) were applied in optimums conditions to investigate the best removal of dyes. The results show that the best method for completely degradation of dyes at short time 10 min irradiation is sonophotolysis.