The olive oil extraction industry is one of the most polluting wastewaters from the food industry, which is considered an important economic activity in the world. The environmental effects of olive wastewater are related to chemical and organic loading, which is resistant to biodegradation processes. The purpose of this study was to determine the efficiency of combined electrocoagulation,
catalytic ozonation, to reduce organic load and improve the biodegradability of olive oil sewage. The present study was experimental on a laboratory scale and was done at a batch reactor on actual olive wastewater. The electrocoagulation process was performed using Fe electrodes at a current density of 0.73, 0.5, 0.05𝐴⁄dm􀬶. The optimal conditions for the electrocoagulation process were
obtained at a flow rate of 0.5 𝐴⁄dm􀬶 for 45 min reaction time, so that the removal efficiency of TOC, COD, and turbidity was 75, 80 and 94%, respectively. Then the treated wastewater under these optimal conditions entered the catalytic ozonation process (COP) reactor. In the COP process, the TOC and COD concentrations reached 105 and 210 mg/L after 90 min (44% and 56% removal).
Eventually, the effluent was introduced into the biology*ical reactor and the removal efficiency of COD and TOC were investigated. So, the amount of TOC and COD decreased from 105 and 210 mg/L to 22.3 mg/L and 37 mg/L, respectively. As a result, the overall efficiency of the EC/COP/SBR system in removing COD and TOC was 98.4% and 97.2%, respectively. The combination of these
processes is very effective in comparison with other processes for the treatment of olive sewage.