Ultrasound-assisted Fenton's treatment of Reactive Black 5 dye: effect of system parameters, kinetics and mechanism

摘要

This study deals with the sonochemical decolourization of aqueous Reactive Black 5 dye solution. The production of highly reactive radicals can be intensified through the addition of various substitutes. The decolourization study of Reactive Black 5 at different experimental conditions, such as the change in pH, bubbling gases (oxygen, argon, nitrogen and air), hydrogen peroxide dosage, sodium chloride dosage, Fenton's reagent and ultrasound probe tip diameter were performed. The maximum decolourization occurs at acidic pH of 3.0, Argon gas bubbling, 8.82mmol/L hydrogen peroxide, 10g/L NaCl addition and the colour removal are the highest for Fenton's reagent-treated Reactive Black 5 dye solution which followed pseudo-first-order rate kinetics. For the entire conditions studied, larger probe tip diameter has shown higher colour removal. Degradation intermediates were identified through GC-MS study. This study shows that decolourization is dominated through the hydroxylation reaction and can suitably be used as a promising method for the decolourization of Reactive black 5 dye.