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United States Department of Agriculture

Agricultural Research Service

Related Topics

Research Project: Sustainable Technologies for Table Olive/olive Mill Wastewater Management

Location: Healthy Processed Foods Research

2013 Annual Report


1a.Objectives (from AD-416):
California’s olive processors consume more than 300 million gallons of water each year. The water is costly to purchase and, after processing, difficult to treat in an environmentally sensitive manner. This problem is becoming acute, with olive acreage having increased by 50 percent over the past 7 years. The proposal’s objectives: improve water quality, increase water conservation, and accelerate Best Management Practices to enhance the economic viability of olive processing in California. ARS will focus on water processing from olive oil production, while UCDOC will focus on water processing from table olive production.


1b.Approach (from AD-416):
1. The project team will obtain wastewater from table olive and olive oil processors during the 2012, 2013, and 2014 harvest seasons: (a) USDA-ARS scientists will test several concentration/drying unit operations such as centrifugation, resin separation, and various drying techniques. (b) UCDOC scientists will test the samples by using lab-scale and industrial-scale membrane filtration systems. 2. For each technique, we will calculate the energy requirement per unit water removed and will evaluate the resulting concentrates/powders for their physical, chemical, and nutritional properties. In addition, we will assess the economic costs and environmental impact of each technology. 3. We will develop a comparison matrix of all techniques and will test integrated wastewater management strategies in late 2014. 4. UCDOC will lead dissemination and distribution of Best Management Practices to olive processors to maximize water conservation, quality and byproduct value.


3.Progress Report:

FY2013 was the first year of a 2.75-year grant project involving Agricultural Research Service and University of California Davis Olive Center (UCDOC). Researchers from UCDOC and ARS collected olive mill wastewater (OMWW) from 3 participating California olive mills in November and December 2013. This material was characterized by ARS and the results shared with the entire project team in early 2013. Throughout the rest of FY2013, ARS researchers investigated separation of the OMWW by centrifugation, and UCDOC researchers investigated separation by membrane filtration. The project postdoctoral research associate established a set of standard physical and chemical assays that will be performed by both ARS and UCDOC in order to determine extent of separation achieved by any tested process. In June 2013, ARS and UCDOC project team members met at one of the participating mills (California Olive Ranch) to discuss progress on the project so far and plan out experiments for the Fall 2013 olive harvest season. From June through September 2013, ARS and UCDOC scientists developed analytical chemistry techniques for characterizing the individual high-value compounds in the OMWW and monitoring these compounds’ fate during the separation process. These activities all contributed to the project objective of accelerating best management practices for OMWW in California by characterizing both the starting material (OMWW) and the streams it can be separated into via centrifugation and membrane filtration.

This subordinate project relates to in-house parent project Objective 3: Develop sustainable microwave processing technologies, both alone and in combination with other processing methods, for specialty crops and their co-products. In this project, microwave-assisted drying will be used to dry down the concentrated product obtained from the various separation methods. In FY13, the focus of the project was on collection, characterization, and separation of OMWW from various olive mills; in future years, the focus will shift to drying the separated products using microwave heating and other sustainable technologies.


Last Modified: 7/25/2014
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