Suchergebnisse

In this work the effectiveness of two saline solutions (NaCl and Na2SO4) to clean a permanently hydrophilic polyethersulfone (PESH) ultrafiltration (UF) membrane with a molecular weight cut-off (MWCO) of 30 kDa previously fouled with enzymatic solutions was investigated. The influence of protein concentration in the enzymatic solution during the fouling step and the effect of salt type during the cleaning procedure were studied. The protein aggregation was analyzed in solution and onto the membrane surface by using several techniques including Dynamic Light Scattering (DLS), Atomic Force Microscopy (AFM) and Infrared Spectroscopy with Attenuated Total Reflectance (ATR-FTIR). In addition, mechanisms that dominate membrane fouling were studied by fitting some mathematical models (Hermia's models adapted to crossflow filtration, a combined model based on the complete blocking and cake formation equations and a resistance-in-series model) to the experimental data. Fouling results showed that the complete blocking/adsorption on membrane surface was the predominant fouling mechanism. Regarding the cleaning results, higher cleaning efficiency and low residual protein concentration was obtained with NaCl solutions for all the feed solutions tested due to the favorable interaction between Cl and proteins. ; Maria-Jose Corbaton-Baguena wishes to gratefully acknowledge the financial support from the Spanish Ministry of Economy and Competitiveness through the grant EEBB-I-14-09011 (project CTM2010-20186). The authors acknowledge the European Union, Fondo Europeo di Sviluppo Regionale, The Ministero dell'Istruzione, dell'Universita e della Ricerca - MIUR, The Ministero dello Svilupppo Economic - MSE - for the financial support to the project "Sistemi tecnologici avanzati e processi integrati della filiera olivicola per la valorizzazione dei prodotti e dei sottoprodotti, lo sviluppo di nuovi settori e la creazione di sistemi produttivi Eco-compatibili" (PON Olio Piu, PON01_01545), within the framework PON Ricerca e ...

207 214 486 ; S ; In this work the effectiveness of two saline solutions (NaCl and Na2SO4) to clean a permanently hydrophilic polyethersulfone (PESH) ultrafiltration (UF) membrane with a molecular weight cut-off (MWCO) of 30 kDa previously fouled with enzymatic solutions was investigated. The influence of protein concentration in the enzymatic solution during the fouling step and the effect of salt type during the cleaning procedure were studied. The protein aggregation was analyzed in solution and onto the membrane surface by using several techniques including Dynamic Light Scattering (DLS), Atomic Force Microscopy (AFM) and Infrared Spectroscopy with Attenuated Total Reflectance (ATR-FTIR). In addition, mechanisms that dominate membrane fouling were studied by fitting some mathematical models (Hermia's models adapted to crossflow filtration, a combined model based on the complete blocking and cake formation equations and a resistance-in-series model) to the experimental data. Fouling results showed that the complete blocking/adsorption on membrane surface was the predominant fouling mechanism. Regarding the cleaning results, higher cleaning efficiency and low residual protein concentration was obtained with NaCl solutions for all the feed solutions tested due to the favorable interaction between Cl and proteins. Corbatón Báguena, MJ.; Gugliuzza, A.; Cassano, A.; Mazzei, R.; Giorno, L. (2015). Destabilization and removal of immobilized enzymes adsorbed onto polyethersulfone ultrafiltration membranes by salt solutions. Journal of Membrane Science. 486:207-214. doi:10.1016/j.memsci.2015.03.061 ; Maria-Jose Corbaton-Baguena wishes to gratefully acknowledge the financial support from the Spanish Ministry of Economy and Competitiveness through the grant EEBB-I-14-09011 (project CTM2010-20186). The authors acknowledge the European Union, Fondo Europeo di Sviluppo Regionale, The Ministero dell'Istruzione, dell'Universita e della Ricerca - MIUR, The Ministero dello Svilupppo Economic - MSE - for the financial support ...

European Union's Seventh Framework Program (FP7/2007-2013) under Grant agreement no. 608490. project M4CO 2 . CNR/FCT Italian/Portuguese Bilateral Project 2015-2016 "Advanced studies of the transport properties and gas separation by polymers of intrinsic microporosity (PIMs) and Ionic Liquid Gel Membranes via novel methods" and the CNR-CAS Bilateral Agreement 2016-2018 "Innovative polymeric membranes for pervaporation and advanced gas and vapour separations". ; A novel method to determine the individual diffusion coefficients of gases in a mixture during their permeation through polymeric membranes is described. The method was developed in two independent laboratories, using rubbery Pebax® and glassy Hyflon® AD60X membrane samples as standards, and validated using the Tröger's base containing Polymer of Intrinsic Microporosity, PIM-EA-TB. Monitoring of the permeate composition in real time by a quadrupole mass spectrometer allowed the analysis of the permeation transient for gas mixtures. Two operation modes, either with a vacuum in the permeate and a direct connection to the mass spectrometer via a heated restriction, or using a sweeping gas and a heated capillary sample inlet, give excellent agreement with the traditional time lag method for single gases. A complete overview of the method development, identification of the critical parameters, instruments calibration, data elaboration and estimation of the experimental accuracy are provided. Validation with PIM-EA-TB, shows that the method can also successfully detect anomalous phenomena, related to pressure and concentration dependency of the transport properties, physical aging or penetrant-induced dilation. Rapid online analysis of the permeate composition makes the method also very suitable for routine mixed gas permeability measurements. ; publishersversion ; published