Isolation Of Purified High Added Value Products From Olive Mill Wastewater Streams Through The Implementation Of Membrane Technology And Cooling Crystallization Process

Olive Mill Wastewater (OMW) and olive leaves are the main by-product associated with olive oil production. OMW is a by-product characterized by the very high concentration of organics and phenolic compounds rendering its biodegradability very difficult. On the other hand, due to the antioxidant properties of phenolic compounds, their recovery and application into different scientific fields, including food, pharmaceuticals, etc, may ameliorate significantly health issues.The current study aimed at the development of an integrated treatment process for the exploitation of OMW to zero waste emission. The proposed method for the more efficient treatment of OMW includes the implementation of membrane technology for the isolation and fractionation of the high added value by-products contained in the concentrate streams of nanofiltration and reverse osmosis. The final reverse osmosis permeate subtracted from the organic loading may be used for reuse in the OMW premises, while the reverse osmosis concentrate, enriched in the phenolic fraction, may be further treated for the investigation of the selective recovery of purified phenolic compounds by cooling crystallization.The recovery of phenolic compounds from OMW streams, was investigated from synthetic OMW prepared according to literature data survey. Glucose and tyrosol were used as model compounds for sugars and for the phenolic fraction respectively. The implementation of membrane filtration employed for the fractionation of monosaccharides and polyphenols in the concentrate streams of nanofiltration and/or reverse osmosis. Finally, the phenolic compounds in the concentrate were obtained by cooling crystallization.