title: Characterization of olive mill wastewater fractions treatment by integrated membrane process.
abstract: BACKGROUND
  Up to now, the management of olive mill wastewaters, a three-phase mill by-product, remains an unsolved problem, in particular for those regions where huge quantities of vegetable water are produced. Olive mill wastewaters were therefore treated to evaluate the characteristics of permeate and retentate fractions produced by an integrated membrane system working at two different volume concentration factors.
  
  
  RESULTS
  The effect of two membrane-based filtration steps (microfiltration and nanofiltration) on the content of chemical oxygen demand, dry matter, sensory quality, phenolic compounds and antioxidant activity of permeate and retentate samples was evaluated. Furthermore, the effect of two different volume concentration factors (VCF), in the nanofiltration step, were investigated. At high VCF values, the total phenolic content in the retentate fraction was found to be 3.7-fold higher than the starting one, while the reduction of chemical oxygen demand in the permeate fraction was greater than 97% also at lower VCF values.
  
  
  CONCLUSIONS
  Each filtration step has provided useful information concerning the utility and appropriateness of the processes chosen, suggesting a sustainable hypothesis of 'normal industrial practice' that can be included in current processes of oil extraction, in order to purify water and recover phenolic compounds with high added value.
authors.affiliation: Department of Agricultural and Food Sciences, Alma Mater Studiorum - University of Bologna, I-47521, Cesena (FC), Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Di Lecce
authors.forename: Alfredo
authors.initials: A
authors.lastname: Cassano
authors.forename: Alessandra
authors.initials: A
authors.lastname: Bendini
authors.forename: Carmela
authors.initials: C
authors.lastname: Conidi
authors.forename: Lidietta
authors.initials: L
authors.lastname: Giorno
authors.forename: Tullia Gallina
authors.initials: TG
authors.lastname: Toschi
mesh_terms: D005374:Filtration / Q000295:instrumentation / Q000379:methods; D019649:Food Industry; D007220:Industrial Waste / Q000032:analysis*; D008567:Membranes, Artificial; D031658:Olea / Q000737:chemistry*; D014865:Waste Disposal, Fluid / Q000379:methods*; D062065:Wastewater / Q000737:chemistry*
chemical_list: D007220:Industrial Waste; D008567:Membranes, Artificial; D062065:Wastewater
keywords: antioxidant activity; microfiltration; nanofiltration; olive mill wastewaters; phenolic compounds