Characterization and Environmental Impact of Olive Mill Wastewater Generated from the Three-Phase Extraction Process

Olive mill wastewater (OMWW) is the main pollutant from the three-phase extraction system of olive oil production. The disposal of OMWW into surface waters represents an important environmental problem in Albania due to huge quantities in short periods (November-February) and high concentrations of organic compounds mainly phenols which cause ecological issues for the ecosystem, such as soil contamination and water pollution. This study focused on characterization of vegetation water effluents generated from three'phase extraction processes of olive oil production to evaluate their environmental impact. Samples of OMWW were collected from different three-phase olive mills operating in southern and central parts of Albania. Physicochemical characterization and multivariate analysis were performed. The results of the physicochemical analysis showed that samples of OMWW had an acid pH (4.4-5.3), high levels of organic load expressed in terms of BOD5 (29.8-48.3 g/l), and COD (126-216.8 g/l), higher levels of total nitrogen (423-635mg/L), oils and grease (5.5-8.5 g/L) compared to allowed effluent discharge limits according to Albanian standards. The biodegradability index of OMWW analyzed exceeds the thresh¬old of 3, confirming that our samples are partially or no biodegradable and the polyphe¬nol concentration was 5.5-8.42 g/l.