Study of kinetic parameters related to the decolourization and mineralization of reactive dyes from textile dyeing using Fenton and photo-Fenton processes

The decolourization and mineralization of two reactive azo dyes, Procion Red H-E7B (CI Reactive Red 141) and Cibacron Red FN-R (CI Reactive Red 238), under Fenton's and photo-Fenton's conditions have been investigated. Some parameters, like temperature, initial concentrations of Fe(II) and H2O2 and the use of natural or artificial light were evaluated aiming to find the optimal conditions to promote the efficient degradation of the dyes. The experimental results showed that the Fenton's process run under solar light was the most effective. Pseudo-first order degradation rate constants were obtained from batch experimental data. It is suggested that Fenton's and photo-Fenton's type reactions are viable techniques for the treatment of such types of reactive dyes, according to the high levels of colour, aromatic content (UV254) and DOC removal.