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

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 ۲۵۰ mL contaminated water with PCE. The effects of parameters, including solution pH (۳-۱۲), current density (۲-۱۰ mA cm-۲), H۲O۲ concentration (۲۰-۷۰ µL H۲O۲ per ۲۵۰ mL sample.), PCE concentration (۵-۵۰ mg L-۱), and electrolysis time (۱-۱۵ 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 ۹۸.۱% was obtained in the optimum condition, including solution pH of ۵, the current density of ۸ mA cm-۲, H۲O۲ concentration of ۵۰ µL per ۲۵۰ mL sample, PCE concentration of ۱۵ mg L-۱, and electrolysis time of ۱۰ min. The kinetics studies of the EF process indicated that the obtained results were in satisfactory agreement with the first-order model (R۲ = ۰.۹۸۵۸, Kapp = ۰.۲۸۲۲). 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.

Keywords:

Aqueous Solution , Degradation , Electro-Fenton Process , Hydroxyl Radical , Perchloroethylene.