A comparative study on the removal of phenol from aqueous solutions by electro-Fenton and electro-persulfate processes using iron electrodes

This study examined the removal of phenol from aqueous solutions through electro-Fenton and electro-persulfate processes using iron electrodes. The effect of operational parameters such as initial pH, current density, initial concentration of phenol, hydrogen peroxide dose, and persulfate (PS) concentration on the removal of phenol were investigated. The results showed that the efficiency of phenol removal was directly related to the initial concentrations of hydrogen peroxide and PS, and was inversely correlated with a highly alkaline pH and elevated concentration of phenol. The efficiency of phenol removal was significantly increased by increasing PS and H2O2 concentrations from 0.1 to 0.4 mM, but there was little influence on removal efficiency with greater quantities of PS and H2O2. Ultimately, phenol was almost completely removed after 45 min in both processes.