en تخصصي Special مقاله اصیل Original Article <div style="text-align: justify;">Background: This research studied the effect of UV light on pentachlorophenol (PCP) removal in the electro-Fenton (EF) process.<br> Methods: PCP was used as the pollutant in this study. The effects of Fenton&rsquo;s reagent, i.e. hydrogen peroxide concentration, solution pH, and treatment time by EF (EF) and photoelectro-Fenton (PEF) processes, were studied to determine rates of PCP removal. The results showed that a better performance and a high removal efficiency were achieved by coupling UV radiation and the EF process.<br> Results: EF processes required more time to remove PCP, while after a reaction time of 10 minutes, the PEF achieved a removal efficiency of 90.4%; this value is higher than the maximum efficiency of the EF process (83.44% after 40 minutes). The kinetic mechanisms of both processes were examined and<br> compared. The rate constants at optimum conditions were 0.0455 and 0.0579 min&minus;1 for EF and PEF processes, respectively.<br> Conclusion: Removal efficiency was obtained in the order of PEF > EF.</div> Ultraviolet rays, Reaction Time, Kinetics 203 207 http://ehemj.com/browse.php?a_code=A-10-1-92&slc_lang=en&sid=1 Zahra Heidari 10031947532846003408 10031947532846003408 No Department of Chemical Engineering, Petroleum University of Technology, Abadan, Iran Mohsen Motevasel 10031947532846003409 10031947532846003409 No Department of Chemical Engineering, Petroleum University of Technology, Abadan, Iran Nematollah Jaafarzadeh jaafarzadeh-n@ajums.ac.ir 10031947532846003410 10031947532846003410 Yes Environmental Technologies Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran