Degradation of High-Concentration of Perchloroethylene from Aqueous Solution Using Electro-Fenton Process

Abstract

Introduction: Perchloroethylene (PCE) is one of the most well-known chlorinated organic compounds recently detected in aqueous environments. The presence of PCE in aquatic ecosystems has caused many health problems and environmental challenges. Therefore, its removal and treatment from aqueous environments are essential.
 Materials and Methods: The electro-Fenton (EF) process was carried out in a cylindrical reactor containing 250 mL contaminated water with PCE. The effects of parameters, including solution pH (3-12), current density (2-10 mA cm-2), H2O2 concentration (20-70 µL H2O2 per 250 mL sample.), PCE concentration (5-50 mg L-1), and electrolysis time (1-15 min) on PCE degradation were investigated. The kinetics and radical’s scavenger of the EF process were examined to detect the exact mechanism of PCE degradation.
 Results: The degradation of the PCE of 98.1% was obtained in the optimum condition, including solution pH of 5, the current density of 8 mA cm-2, H2O2 concentration of 50 µL per 250 mL sample, PCE concentration of 15 mg L-1, and electrolysis time of 10 min. The kinetics studies of the EF process indicated that the obtained results were in satisfactory agreement with the first-order model (R2 = 0.9858, Kapp = 0.2822). Also, the addition of ethanol and tertiary butanol caused an inhibiting effect.
 Conclusion: The EF process was effectively applied to degrade PCE from polluted water as an efficient technique. The obtained results indicated that the generation of •OH throughout the EF process was the key mechanism that controlled the EF process.