Selective isolation of valuable biophenols from olive mill wastewater

• Selective sorption of the biophenols was achieved in model and natural OMW.
• Performance of 16 adsorbents and 32 MIPs and NIPs was experimentally determined.
• Individual phenolic compounds were isolated from OMW by a reasonable strategy.

A number of experimental procedures using acidification, sedimentation and membrane filtration process of natural olive mill wastewater (OMW) have been conducted. Valuable biophenols were isolated from multi-compound model and natural OMW under different conditions. Selective uptake of hydroxytyrosol, tyrosol, caffeic acid, oleuropein and luteolin was investigated onto 16 commercial sorbents. AFs resins demonstrated the highest selectivity towards hydroxytyrosol and tyrosol and thus, the extraction of these compounds was evaluated and optimized. Molecularly imprinted polymers (MIPs) were also used to recover the biophenols from OMW. MIPs seem to constitute a promising technology with regard to the recovery of biophenols from OMW. The loading of both hydroxytyrosol and tyrosol was much higher onto AFs resins, while the desorbed ratios were much higher from the MIP. The results demonstrate a possibility to gain individual biophenols and/or particular phenolic subclasses from OMW by combining an effective pretreatment with the different appropriate sorbents in series.

Olive mill wastewater after (a) acidification, (b) ultrafiltration and (c–e) adsorption onto AFs resins.Figure optionsDownload as PowerPoint slide