Degradation of Sulfonated Azo Dyes with Sodium Percarbonate

Abstract

Sulfonated hydroxyarylazo and aminoarylazo dyes were reacted with sodium percarbonte in water at pH 10.6 and at various temperatures. We have determined the initial rate and the apparent activation energy of the decoloration reaction. The results suggest a greater susceptibility to attack of the hydrazone form than the azo form. Aminoarylazo dyes are more resistant to degradation relative to similar hydroxyarylazo dyes, which contain a hydroxyl group that can be ionized in alkaline solutions. They are more resistant and have greater apparent activation energy than the others.