Geraldes, V.Minhalma, Miguelde Pinho, M. N.Anil, A.Ozgunay, H.Bitlisli, B. O.Sari, O.2013-10-242013-10-242009GERALDES, V.; MINHALMA, M.; PINHO, M. N. de; ANIL, A.; OZGUNAY, H.; BITLISTI, B. O.; SARI, O. - Nanofiltration of Cork Wastewaters and Their Possible Use in Leather Industry as Tanning Agents. Polish Journal of Environmental Studies. ISSN 1230-1485. Vol. 18, nr 3 (2009), p. 353-357.1230-148510.1016/j.memsci.2007.12.057http://hdl.handle.net/10400.21/2770Cork processing wastewater is a very complex mixture of vegetal extracts and has, among other natural compounds, a very high content of phenolic/tannic colloidal matter that is responsible for severe environmental problems. In the present work, the concentration of this wastewater by nanofiltration was investigated with the aim of producing a cork tannin concentrate to be utilized in tanning. Permeation results showed that the permeate fluxes are controlled by both osmotic pressure and fouling/gel layer phenomena, leading to a rapid decrease of permeate fluxes with the concentration factor. The rejection coefficients to organic matter were higher than 95%, indicating that nanofiltration has a very good ability to concentrate the tannins and produce a permeate stream depleted from organic matter. The cork tannin concentrate obtained by nanofiltration and evaporation had total solids concentration of 34.8 g/l. The skins tanned by this concentrate were effectively converted to leather with a shrinking temperature of 7 degrees C.engNanofiltrationCork wastewaterTanninTanningLeatherProcessing wastewatersIntegrated processFentons reagentWaste-waterOxidationUltraFiltrationRemovaljournal article