Organic effluent oxidation tests were conducted in petrochemical companies, in the Camaçari Petrochemical Complex, to reduce treatment costs and improve the primary treatment efficiency in each industrial process. Ozone achieved 99.96 percent benzene reduction and 100 percent ethyl benzene and toluene reduction. Process efficiency is strongly dependent on the wastewater chemical composition and concentration. For this reason it is necessary to run pilot plant trials for each specific case. Ozone was obtained feeding commercial oxygen through a corona discharge generator and dissolved in the effluent with a bubble column. Commercial oxygen was used instead of air to increase 250 percent the ozone production, with the same ozone generator.