Oxidation of Phenol by Microbubble-assisted Microelectrolysis

Removal of phenol under iron-carbon (Fe-C) microelectrolysis was enhanced by O2-microbubble. The removal rate (R0) of phenol reached 65% in 2 h. O2 bubbling plays a critical role, as compared to the air and N2 bubbling, in which only 9.5% and 4% of phenol is removed in 2 h, respectively. It shows that more dissolved oxygen in water is favorable for the oxidation process. Phenol removal is effective at lower temperature or/and higher dissolution pressure also confirms the role of dissolved oxygen. In the microbubble-assisted microelectrolysis system, O2, Fe-C pellets, and H2SO4 are the necessary conditions for the oxidation of phenol. The conversion of phenol follows the kinetics of the pseudo-first order, polynomially increases with the increasing amount of Fe-C pellets or/and sulfuric acid. Catechol, hydroquinone, and low molecular carboxylic acids are the major products.