Fast decolourization of Indigo Carmine and Crystal Violet in aqueous environments through micellar catalysis

Abstract

Herein we report the modulating effect of sodium dodecyl sulphate (SDS), hexadecyl-pyridinium chloride (HDPC) and octylphenol ethoxylate (Triton X100) on the degradation of indigo carmine (IC) and crystal violet (CV) in bicarbonate-activated peroxide (BAP) system. Upon the addition of surfactant/BAP “surfoxidant ”, the decolourization degrees of both dyes were above 60% after 5 min, and the total organic carbon removal after 15 min varied within 44 –50%. While SDS has shown rather an inhibitory effect during the oxidation of CV, HDPC and Triton promoted the oxidation of both CV and IC, particularly HDPC when a 10-fold increase of the decolourization rate was obtained. This behaviour suggests the formation of active entities –kinetic micelles acting as nano-reactors by “enclosing ” reactants in small-sized aggregates with volumes ranging from 30 to 720 nm3.