Background and & Objectives: Chlorophenols are classified as non-biodegradable hazardous materials. Therefore, the purpose of this study was investigation of electro-Fenton and UV/TiO₂ processes efficiencies in removal of para-chlorophenol from aqueous solution.

Methods: In this experimental study a cylindrical glass equipped with 2 iron electrodes with total effective surface area of 50 cm², as a electro-Fenton reactor, and  a quartz cylindrical reactor with a volume of 190 ml equipped with 2 UVA lamps (6watt), as a photocatalysis reactor, were used to remove para-chlorophenol. The operating parameters of electro-Fenton process such as initial para-chlorophenol concentration, pH, H₂O₂ concentration and current density were investigated. Then obtained effluent was introduced to UV/TiO₂ process and operating parameters such as TiO₂ dosage and pH were examined.

Results: The results showed that para-chlorophenol removal efficiency of 65% was achieved in pH=3, H₂O₂=5 mM, current density=3 mA/cm², and reaction time of 45 min. In combination of electro-Fenton and UV/TiO₂ (pH=5.8 and TiO₂=1.5 g/L) processes the removal efficiency of 97% was attained.

Conclusion: The results revealed that combination of electro-Fenton and UV/TiO₂ processes is an efficient method to remove para-chlorophenol from aqueous solutions.