Discoloration Study of Azo Dye Solution Using the Fenton Process

Abstract

The discoloration of Carmoisine at an initial concentration of 1 g/L, by the Fenton process (Fe2+/ H2O2) has been studied. The efficiency of this process in the discoloration of Carmoisine, as well as the influence of the reaction parameters, was discussed. The effects of initial pH, Fe2+ and H2O2 concentrations, and treatment duration on the discoloration kinetic were evaluated. Our results showed that the best discoloration efficiency has reached 94 % and was achieved in 20 minutes of treatment with 3.57 mmol/L Fe2+, 194.1 mmol/L H2O2, at pH = 3. The discoloration kinetics of the carmoisine followed the BMG model.

A Rotatable Paper Device Integrating Reverse Transcription Loop-Mediated Isothermal Amplification and a Food Dye for Colorimetric Detection of Infectious Pathogens

“…Using hydroxyl radicals created from the reaction between CuSO 4 and H 2 O 2 , the azo linkage of carmoisine can be degraded to form two naphthalene molecules. Through degradation of the azo linkage, the dye can be decolorized [ 16 , 17 , 18 , 19 ]; however, the presence of a large number of DNA molecules reduces the effect of hydroxyl radicals on carmoisine because DNA can competitively react with hydroxyl radicals [ 20 , 21 ]. In the absence of DNA amplicons, the color of carmoisine is reduced from red to light pink; in the presence of DNA amplicons, the color of carmoisine remains red ( Figure 1 ).…”