Abstract
Tests for the photocatalytic degradation of solutions of three reactive dyes, Red M-5B, Procion Blue MX-R and Procion Black H-N, in the presence of H2O2 were carried out. When the solutions of the three reactive dyes were irradiated by UV or solar light, the colour of the solutions disappeared gradually. A statistical analysis of the test results indicated a linear relation between the concentration of dyes and the time of irradiation. The discolouration reaction of the solutions was of the first order. Rate equations for the discolouration reactions of dye solutions were developed.
The dark reactions or the dye solutions containing H2O2 were very slow, illustrating that the photochemical reaction played a very important role. It was demonstrated that UV light and solar light (300 to 380 nm) photolyzes the HO and that the resulting OH radical reacts with the dye molecules and destroys the chromophore.
Investigation into the reaction of reactive dyes with carboxylate salts and the application of carboxylate‐modified reactive dyes to cotton