California Olive Oil News has received an advance copy of an excellent book summarizing the problem of waste disposal in the olive oil industry. Professor C.P Halvadakis and Dr. M. Niaounakis of the University of the Aegean in Mytilene, Greece have put together a literature review and more interestingly a patent survey of olive mill waste devices.
The book addresses several waste components created during olive oil production; tree prunings, leaves and twigs harvested along with the olives, and the olive water and pomace from modern centrifugal olive mills. Halvadakis and Niaounakis discuss the unique and growing problem of watery pomace as the Spanish industry has switched almost universally to 2 phase decanters. The authors cite over 1000 references and patents.
They start with a history of olive mill waste. From 2,500 years ago to about 25 years ago, streams and rivers were the most common way to dispose of olive waste with increasingly devastating impact on the environment. As laws were passed preventing this, researchers and inventors have come up with alternate routes of disposal.
Olive mill waste has many stubborn characteristics. Its water content is high so drying or combustion schemes are energy intensive or polluting. The polyphenols we cherish in the oil are a nuisance in the waste. They prevent oxidation and biological degradation and are difficult to extract for other uses. The waste is created in large quantities for a short part of the year.
The book is a sobering read as no solution discussed seems to be economical or without its own problems. Advantages and disadvantages are presented for sedimentation, filtration, flotation, centrifugation, combustion, pyrolysis, lagooning, neutralization, chemical treatment, anaerobic and aerobic processes, composting and phytoremediation, among others. This text is sorely needed and will undoubtedly prod further research in the field.
For more information contact:
Waste Management Laboratory
Department of Environment
University of the Aegean
Mytilene, P.C. 81 100 GR
fax. +30 22510 36274