Different Advanced Oxidation Processes (Photo Fenton process, Fenton process and H₂O₂/UV) were studied in order to reduce COD from oily compounds aqueous solution using batch system. To get the optimum condition, different variables were studied for each of these processes; such as pH, time, concentration of H₂O₂, concentration of oil, concentration of FeSO₄·7H₂O and temperature as parameters. It was found that the optimal pH value for the three processes was 3 and the optimal temperature was 30^oC for Photo-Fenton and UV/H₂O₂ system and 20^oC for Fenton process. Photo-Fenton process gave a maximum COD reduction of 80.59 % (COD from 2684 to 521 mg/l), Fenton gave 53.22 % (COD from 2587-1130) and the combination of UV/H₂O₂ gave a COD reduction of 22.69 % (COD from 2450 to 1894). The percentage of removal found was after the total reaction time (180 min.). The optimum chemical reagents for Photo-Fenton, Fenton and UV/H₂O₂ were as the following H₂O₂ = 800 mg/l, 1500 mg/l and 2000 mg/l, Fe₂SO₄·7H₂O = 60 mg/l, 100 mg/l.