Olive mill waste-waters (OMWW) are rich in polyphenols. In order to remove polyphenols from OMWW, an integrated process including precipitation and polyphenol removal by liquid-liquid extraction is proposed. The precipitation was required to avoid crud formation during liquid-liquid extraction. Different concentrations of FeCl_3 and lime were tested, with or without a flocculant. Several commercial extractants were tested to remove polyphenols from pre-treated OMWW. The raffinates were analysed by HPLC. None of extractants were selective for polyphenols. However, combination of two extractants, in a sequential extraction resulted in the recovery of an organic solution rich in hydroxytyrosol, which could be stripped with caustic soda. Synthetic polyphenol solutions extractions were also experimented.
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