Introduction & Objective: Pentachlorophenol (PCP) is a refractory phenolic compound. Owing to its high poisonous and carcinogenic nature, PCP is on the US EPA’s list of priority pollut-ants. As a result, it is one of the important pollutants that need to be removed during water and wastewater reclamation processes. The efficiency of the catalytic ozonation process (COP) was assessed based on the removal of PCP from the aqueous solutions and its intermediates were studied.

Materials & Methods: In this experimental study, catalytic ozonation process was applied to remove PCP in aqueous solution and its intermediate was studied. The influence of several variables was examined, including pH of solution, contact time, dissolved ozone concentra-tion and dosage of -Al2O3 in semi batch reactor. The determination of PCP concentrations in solutions was analyzed by HPLC using the UV detector (254nm).

Results: Our results showed that the removal effectiveness of PCP has been increased by rising pH, contact time, catalyst dosage and dissolved ozone concentration. Removal efficiency of PCP was determined 89% and 100% in SOP and AOP after 60 minutes, respectively. The pHzpc of alumina was determined 8.6.

Conclusion: Due to high performance of -Al2O3 as catalyst in catalytic ozonation and increasing the PCP removal, it is thus concluded that the integrated catalytic ozonation is a promising and economically affordable technology for the treatment of wastewater containing pen-tachlorophenol and other similar compounds.