Discoloration of Waters Containing Azo Dye Congo Red by Fenton Oxidation Process Estimation of activation parameters

作者：Dragoi Madalina; Samide Adriana^*; Moanta Anca

来源：Revista de Chimie, 2011, 62(12): 1195-1198.

• Congo red
• Fenton reagent
• discoloration process
• UV-Vis spectra

The discoloration of waters containing Congo red using Fenton reagent was studied at different pH values and different temperatures. The results reported a significant discoloration after 5 min, at pH = 3.50 and temperature of 55 C. In these conditions, it was obtained a color removal (CR) equal to 75.6 +/- 5 and a relative discoloration rate of 14.12 % / min. Apparent activation energy was determined using the Arrhenius equation. The value of E was determined as being equal to 85.9 kJ/mol. The activation enthalpy (Delta H degrees) and the activation entropy ((a)Delta S(0)) were calculated from the diagram of the transition state. The value of the enthalpy (83.44 kJ/mol indicates an endothermic reaction. Positive values of entropy (30.78 J/mol) suggest that entropy increases upon achieving the transition state, which often indicates a dissociating mechanism.

• 出版日期2011-12