Students Win Award for Olive Waste Treatment

Source: The Olive Oil Source
February 09, 2008

University of Utah students in partnership with students at Birzeit University in the Palestinian territories have won the Mondialogo Engineering Award for a method of extracting toxic phenols from olive processing waste. By removing the phenols the wastewater can be safely disposed and the chemicals can be sold to the pharmaceutical and cosmetics industries.


According to the Mondialogo organization literature, the Award "invites engineering students in developing and developed countries to form international teams to create project proposals that address the United Nations Millennium Development Goals – proposals to improve the quality of life in the developing world, particularly poverty eradication and the promotion of sustainable development."


Mondialogo was launched by UNESCO and Daimler and "seeks to promote intercultural dialogue, understanding and exchange among young people." 809 student groups from 89 countries registered for the 2007 award. The contestant teams were asked to engage in international intercultural cooperation and dialogue from December 2006 to May 2007, to propose practical, high-quality engineering projects for the benefit of communities in developing countries. Ten Mondialogo Engineering Awards, twenty Honorable Mentions and one Continuation Award went to the 31 finalist project teams which represented several different areas of engineering.




Effect of wastewater after drying on land - courtesy Mondialogo


Olive mill pollution is a problem throughout the olive producing parts of the world. The olive paste and waste processing water left after olive oil extraction are full of polyphenols. Polyphenols are a broad class of healthful antioxidants including Flavenoids and catechins which help repair cell damage and are found in high levels in olive oil, red wine, chocolate, tea and many other foods. These substances are water soluble so are mostly found in the waste water after olive processing. The levels are so high that they represent one of the biggest problems in disposing of olive waste. The phenols have anti-fungal and anti-bacterial activities so can disturb normal wetland or treatment pond ecology. The olive water can contaminate surface waterways and groundwater. In the Ramallah District of the West Bank alone there are approximately 65 olive mills. During the peak olive oil production season the effluent flow can be substantial.


The Utah and Palestine team came up with methods of removing these toxic compounds so that the waste can be used for biogas production and the water treated for reuse by the mills. Once extracted in a usable form, the compounds can also be sold to the pharmaceutical and cosmetics industries.


In California the olive waste is treated a variety of different ways depending on whether a 2 or 3 phase decanter centrifuge is used. Most of the more modern decanters are 2 phase. The older 3 phase type is used in Palestine. 2 phase decanter centrifuges produce a watery husk. The watery husk is considered less of a disposal problem than the olive water produced in a 3 phase decanter. It can be spread back on the field, trucked to landfill or is occasionally dried onsite in commercially available dryers. The dryer may cost more than the decanter and consume high quantities of energy in the form of electricity, fossil fuels or by burning the subsequently dried husk. In all cases, greenhouse gasses and fumes are produced. California's biggest olive mill is at California Olive Ranch in Oroville, CA. They have a pomace dryer and burn the pomace to generate heat which is then used in the olive oil extraction process.


For more information on olive waste disposal see our olive waste page