Nowadays, it is important to treat industrial wastewater for removal of harmful substances like oils. A significant amount of olive oil wastewater is produced in conventional methods of extraction because of the use of large amount of water. The photocatalytic degradation method is used for the treatment of olive oil wastewater because of the complete mineralization of organic pollutants and their conversion to carbon dioxide, water, and mineral acid. The photocatalytic degradation has the advantages of the ability to perform at ambient temperature and pressure and no disposal of excess residues. In order to model and optimize the photocatalytic degradation, central composite design was used. The independent parameters were initial COD (mg/L), TiO2 dose (g/L), pH, time (h), and H2O2(mg/L). The responses were the removal of COD, total phenols, and color. The experimental analysis showed good fitness between models and experimental data. At the optimal point the removal of COD of 60.6%, removal of total phenols of 88.42%, and removal of color of 84.48% were obtained.
