Study of advanced oxidation of basic dyes by Fenton reaction (Fe²⁺/H₂O₂)

ABSTRACT

The process of advanced oxidation by Fenton reaction (Fe²⁺/H₂O₂) was studied in this work for decolorization of two synthetic effluents, containing the dyes Methylene Blue (MB) and Rhodamine B (RB). Experimentally, solutions at concentrations of 10 mg L^-1 of the dyes were exposed to different concentrations of the oxidizing agent (H₂O₂) and catalyst (Fe²⁺⁾ at a temperature of 27 °C and pH 3. The results showed high levels of color removal, with efficiency of 96% for MB and 86% RB. The data showed good adjustment to the kinetic model. The monitoring of the absorption spectrum of the dyes showed a reduction in amplitude of the peaks related to the chromophoric groups in both compounds, confirming the levels of efficiency achieved. The analysis of removal of organic matter in terms of Chemical Oxygen Demand (COD) did not follow the same rate of decrease of decoloration, resulting in reductions of 40.9% for MB and 25.5% for the RB.

Keywords:
Fenton; decoloration; kinetic; basic dyes.