Performance modeling and cost analysis of a pilot-scale reverse osmosis process for the final purification of olive mill wastewater

• Published in: Membranes (Basel) 2013-10, Vol.3 (4), p.285-297
• Main Authors: Ochando-Pulido, Javier Miguel, Hodaifa, Gassan, Victor-Ortega, Maria Dolores, Martinez-Ferez, Antonio
• Format: Article
• Language: English
• Subjects: advanced oxidation processes; Flocculation; Food industries wastewaters; Fouling; Industrial production; Membrane processes; Membranes; modelization; olive mill wastewater; Olive oil; Reverse osmosis; wastewater reclamation
• ISSN: 2077-0375; 2077-0375
• DOI: 10.3390/membranes3040285

A secondary treatment for olive mill wastewater coming from factories working with the two-phase olive oil production process (OMW-2) has been set-up on an industrial scale in an olive oil mill in the premises of Jaén (Spain). The secondary treatment comprises Fenton-like oxidation followed by flocculation-sedimentation and filtration through olive stones. In this work, performance modelization and preliminary cost analysis of a final reverse osmosis (RO) process was examined on pilot scale for ulterior purification of OMW-2 with the goal of closing the loop of the industrial production process. Reduction of concentration polarization on the RO membrane equal to 26.3% was provided upon increment of the turbulence over the membrane to values of Reynolds number equal to 2.6 × 104. Medium operating pressure (25 bar) should be chosen to achieve significant steady state permeate flux (21.1 L h-1 m-2) and minimize membrane fouling, ensuring less than 14.7% flux drop and up to 90% feed recovery. Under these conditions, irreversible fouling below 0.08 L h-2 m-2 bar-1 helped increase the longevity of the membrane and reduce the costs of the treatment. For 10 m3 day-1 OMW-2 on average, 47.4 m2 required membrane area and 0.87 € m-3 total costs for the RO process were estimated.