title: Pilot scale nanofiltration treatment of olive mill wastewater: a technical and economical evaluation.
abstract: The treatment of large volumes of olive mill wastewater is presently a challenge. This study reports the technical and economical feasibility of a sequential treatment of olive mill wastewater comprising a dissolved air flotation pre-treatment and nanofiltration. Different pilot nanofiltration assays were conducted in a concentration mode up to different volume reduction factors (29, 45, 58, and 81). Data attained demonstrated that nanofiltration can be operated at considerably high volume reduction factors and still be effective towards the removal of several components. A flux decline of approximately 50% was observed at the highest volume reduction factor, mainly due to increase of the osmotic pressure. Considerably high rejections were obtained across all experiments for total suspended solids (83 to >99%), total organic carbon (64 to 99%), chemical oxygen demand (53 to 77%), and oil and grease (67 to >82%). Treated water was in compliance with European legal limits for discharge regarding total suspended solids and oil and grease. The potential recovery of phenolic compounds was evaluated and found not relevant. It was demonstrated that nanofiltration is economically feasible, involving operation costs of approximately 2.56-3.08 €/m3, depending on the working plan schedule and volume reduction factor, and requiring a footprint of approximately 52 m2to treat 1000 m3of olive mill wastewater.
authors.affiliation: iBET, Instituto de Biologia Experimental e Tecnológica, Apartado 12, 2780-901, Oeiras, Portugal.
authors.forename: S
authors.initials: S
authors.lastname: Sanches
authors.affiliation: iBET, Instituto de Biologia Experimental e Tecnológica, Apartado 12, 2780-901, Oeiras, Portugal.|REQUIMTE/Chemistry Department, Faculdade de Ciências e Tecnologia, UNL, Caparica, Portugal.
authors.forename: M C
authors.initials: MC
authors.lastname: Fraga
authors.affiliation: Adventech - Centro Empresarial e Tecnológico, Rua de Fundões, 151, 3700-121, São João da Madeira, Portugal.
authors.forename: N A
authors.initials: NA
authors.lastname: Silva
authors.affiliation: Adventech - Centro Empresarial e Tecnológico, Rua de Fundões, 151, 3700-121, São João da Madeira, Portugal.
authors.forename: P
authors.initials: P
authors.lastname: Nunes
authors.affiliation: REQUIMTE/Chemistry Department, Faculdade de Ciências e Tecnologia, UNL, Caparica, Portugal.
authors.forename: J G
authors.initials: JG
authors.lastname: Crespo
authors.affiliation: iBET, Instituto de Biologia Experimental e Tecnológica, Apartado 12, 2780-901, Oeiras, Portugal. vanessap@itqb.unl.pt.
authors.forename: V J
authors.initials: VJ
authors.lastname: Pereira
mesh_terms: D057919:Biological Oxygen Demand Analysis; D005374:Filtration; D036103:Nanotechnology / Q000191:economics / Q000379:methods; D031658:Olea / Q000737:chemistry*; D010636:Phenols / Q000032:analysis; D010865:Pilot Projects; D014865:Waste Disposal, Fluid; D062065:Wastewater / Q000737:chemistry*; D018508:Water Purification / Q000191:economics / Q000379:methods
chemical_list: D010636:Phenols; D062065:Wastewater
keywords: Economical evaluation; Nanofiltration treatment; Olive mill wastewater; Pilot scale; Technical evaluation