Reducing the Environmental Impact of Olive Mill Wastewater

Problem Statement: A research was needed to monitor the environmental impact of olive mill wastewater (OMW): production and relative production of olive mill waste. This was achieved by collecting data from 92 local olive mills in order to study the olive production yield, water consumption in olive washing and in oil recovery, wastewater generation relative to olive processed and oil generated, and solid waste generation. The OMW is usually discharged in the open environment, thus producing pollution to the soil surface and underground water. Approach: The progress on this problem is made by reducing the chemical oxygen demand (COD) as a major OMW pollutant. An upper flow anaerobic sludge bed (UASB) facility was constructed and operated for eight months in a progressive program operation for standardization and optimization purpose, and so to treat the waste by COD reduction. Results: The results reveal local variation in most of the investigated parameters. The olives in some area are found to contain large solid waste than other areas, resulting in lower oil yield and higher solid generation per ton of olive produced. The COD concentration was increased gradually from 5,000-30,000 mg/L and the efficiency improved significantly during the operation from 46%-84% COD removal. The organic load of OMW 27,000mg/L was reduce below 5,000 mg/L, that permits its direct discharge into municipal wastewater treatment plants. Conclusion: The implications and relevance of the results imply that OMW must be treated before discharge to the sewer system. On the other hand, the nonconformity between areas must be taken into consideration for future work.