Effects of harvest date, irrigation level, cultivar type and fruit water content on olive mill wastewater generated by a laboratory scale ‘Abencor’ milling system

• Published in: Bioresource technology Vol. 107; pp. 87 - 96
• Main Authors: Aviani, I., Raviv, M., Hadar, Y., Saadi, I., Dag, A., Ben-Gal, A., Yermiyahu, U., Zipori, I., Laor, Y.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.03.2012
• Subjects: Agricultural Irrigation; Agro-industrial wastes; Concentration (composition); Food Industry; Fruit ripeness; Fruit water content; Fruits; Hydrogen-Ion Concentration; Industrial Waste; Irrigation; Mills; Moisture content; Olea; Olives; Phytotoxicity; Salinity; Vegetable water; Waste water; Water Pollutants; Fruit ripeness; Agro-industrial wastes; Phytotoxicity; Fruit water content; Vegetable water
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2011.12.041

► We studied the effects of olive horticultural conditions on olive mill wastewater. ► Irrigation and fruit maturation significantly influenced wastewater properties. ► There was no correlation between fruit water content and wastewater properties. ► The variability of olive mill wastewaters should be considered in their management. Olive mill wastewaters (OMW) were obtained at laboratory scale by milling olives from four cultivars grown at different irrigation levels and harvested at different times. Samples were compared based on wastewater quantity, pH, suspended matter, salinity, organic load, total phenols, NPK, and phytotoxicity. Principal component analysis discriminated between harvest times, regardless of olive cultivar, indicating substantial influence of fruit ripeness on OMW characteristics. OMW properties were affected both by the composition and the extraction efficiency of fruit water. As the fruit water content increased, the concentrations of solutes in the fruit water decreased, but the original fruit water composed a larger portion of the total wastewater volume. These contradicting effects resulted in lack of correlation between fruit water content and OMW properties. The significant effects shown for fruit ripeness, irrigation and cultivar on OMW characteristics indicate that olive horticultural conditions should be considered in future OMW management.