Abstract
The effect of operating factors on the advanced oxidation performance of an electrochemical flow cell by the Fenton-type reaction of ferrous ion (Fe2+) and hypochlorous acid (HOCl) was discussed in this research. As a result of the research, the balance between the generation rates of Fe2+ and HOCl was found to be of critical importance in the overall current efficiency (CE) of the process. The linear velocity of flow water on the electrodes affected the CE through the change in diffusion flux. A rise in linear velocity enhanced the diffusion flux and CE, but extremely high linear velocity degraded the CE owing to reverse reactions on counter electrodes. An increase in iron concentration also enhanced the CE as a result of the enhancement of Fe2+ regeneration, but iron concentration greater than 27.5 mM deteriorated the CE because of the formation of a brown deposit on the cathode. The current density directly affected the balance between the Fe2+ and HOCl generation rates. The increase in current density enhanced the CE of HOCl production, but deteriorated the CE of Fe2+ regeneration. Accordingly, a decrease in the areal ratio of the anode to the cathode was effective in improving the overall CE.
