Investigation of Phenol Removal from Aqueous Solutions by Electrofenton and Electropersulfate Processes

Phenol, or benzene hydroxyl is a toxic aromatic hydrocarbon discharged into the environment through certian industrial effluents which, thereby, pollute water resources. This study examines phenol removal from aqueous solutions through electro-Fenton and electro/persulfate processes using iron electrodes. For this purpose, a laboratory-scale electrochemical batch reactor was used that was equipped with four electrodes and a direct DC power supply. In the tests carried out, the effects of operational parameters such as initial pH; current density; and initial concentrations of phenol, hydrogen peroxide, and persulfate on the removal of phenol were investigated. The results showed that EPS and EF processes achieved phenol removal efficiencies of 95.18% and 93.99%, respectively, at operating conditions of pH = 3, initial phenol concentration of 100 mg/l, hydrogen peroxide and persulfate concentration of 0. 4 mM, and a current density 0.07A/dm2 over 45 min. Increasing persulfate and hydrogen peroxide concentration from 0.4 to 0.8 mM reduced phenol removal efficiencies from 95.18% and 93.99% to 43% and 85%, respectively. Generally speaking, EPS and EF processes exhibited almost identical phenol removal efficiencies. Finally, the integrated electrochemical and persulphate process was found to be more productive in producing electrical iron and persulphate activation than using each single process in isolation.