Faradaic processes on activated carbon particles: Example of sulfite anodic oxidation

Activated carbon has often been reported as a suitable material for numerous applications e.g. energy storage, batteries and pollution control, due its high adsorption capacity allowed by its high surface area. Besides, activated carbon can also be used for the chemical transformation of matter through faradaic processes. This paper deals with the performance of activated carbon (AC) particles as an electrode material for the anodic oxidation of sulfite and bisulfite species into sulfate. The oxidation was carried out at the surface of a packed-bed of AC particles (volume 170 cm(3)); the main operating conditions, namely potential and solution pH were varied. The sulfate production was shown to be controlled by the electrode kinetics and the internal transfer in the carbon pores. Interactions between the capacitive phenomena, occurring in the electrical pretreatment, and the faradaic processes were discussed.