Kinetic study on regeneration of FeEDTA in the wet process of NO removal

Cyclic voltammetry, quasi-steady-state polarization curves and potentiostatic step method were applied to study the regeneration of Fe^IIEDTA in the wet process of NO removal. The results showed that the Fe^IIIEDTA reduction was a fast reversible process with one electron transferred on Pt electrode surface. Standard rate constant k⁰ of Fe^IIIEDTA reduction at 298 K was found to be 0.0263 cm s⁻¹. According to the calculated diffusion activation energy of 24.93 kJ mol⁻¹, apparent activation energy of 25.74 kJ mol⁻¹ and the electron transfer activation energy of 16.56 kJ mol⁻¹, the rate-determining step for Fe^IIIEDTA reduction was diffusion step. Potentiostatic electrolysis tests revealed that direct electrochemical regeneration of Fe^IIEDTA in the wet process of NO removal was a promising method because of its high efficiency.