Decolourisation of brilliant green under ultrasonic radiations

Abstract

Ultrasonic radiations from a Mullard generator with barium titanate crystal as transducer having a frequency 1 MC/sec. and power output 225 W/sq. cm. have been used to study the decolourisation of aqueous solutions of brilliant green dye. Absorption curves obtained from spectrophotometric data demonstrate the fading of the colour of the dyestuff with the time of exposure. The reaction has been found to he unimolecular and average velocity constants are 0.739, 0.452 and 0.365 for concentrations 0.0064, 0.0096 and 0.0128 g./l. respectively. The presence of small amount of ethyl alcohol inhibits the fading. Cavitation and oxidation due to the presence of some activated oxygen from the dissolved air seem to be the cause of fading.