Effectiveness of photochemical and sonochemical processes in degradation of Basic Violet 16 (BV16) dye from aqueous solutions

In this study, degradation of Basic Violet 16 (BV16) by ultraviolet radiation (UV), ultrasonic irradiation (US), UV/H 2 O 2 and US/H 2 O 2 processes was investigated in a laboratory-scale batch photoreactor equipped with a 55W immersed-type low-pressure mercury vapor lamp and a sonoreactor with high frequency (130kHz) plate type transducer at 100W of acoustic power. The effects of initial dye concentration, concentration of H 2 O 2 and solution pH and presence of Na 2 SO 4 was studied on the sonochemical and photochemical destruction of BV16 in aqueous phase. The results indicated that in the UV/H 2 O 2 and US/H 2 O 2 systems, a sufficient amount of H 2 O 2 was necessary, but a very high H 2 O 2 concentration would inhibit the reaction rate. The optimum H 2 O 2 concentration was achieved in the range of 17 mmol/L at dye concentration of 30 mg/L. A degradation of 99% was obtained with UV/H 2 O 2 within 8 minutes while decolorization efficiency by using UV (23%), US (<6%) and US/H 2 O 2 (<15%) processes were negligible for this kind of dye. Pseudo-first order kinetics with respect to dyestuffs concentrations was found to fit all the experimental data.