Recovery of Phenolic Compounds From Olive Oil Mill Wastewaters by Physicochemical Methodologies

Abstract

Olive oil mill wastewater (OMWW) is one of the main wastes generated during the production of olive oil and represents the main environmental problem of this production process. The treatment of OMWW is extremely difficult due to its great volume and the high concentration of organic matter. Its principal components are polysaccharides, sugars, polyphenols, polyalcohols, proteins, organic acids, and oil. Among them, phenolic compounds represent one of the major factors of the environmental problems caused by OMWW. They are present in high concentration and they have different negative effects, such as phytotoxicity, toxicity against aquatic organisms, suppression of soil microorganisms, and they are difficult to decompose. Despite that fact, phenolic compounds possess high antioxidant activity that makes them interesting for the food, pharmaceutical, and cosmetic industry. Because of that, the recovery of these compounds by different physicochemical methodologies represents an important objective for olive oil industry that will help to obtain interesting extracts and diminish the volume of one of the main olive oil industry by-products. Thus, this chapter reviews the recovery of phenolic compounds from OMWW by different extraction systems, such as membrane filtration, ionic resin purification, adsorbent materials, and solvent extraction.