Catalogo Articoli (Spogli Riviste)

OPAC HELP

Titolo:
How unsteady filtration conditions can improve the process efficiency during cell cultures in membrane bioreactors
Autore:
Mercier-Bonin, M; Daubert, I; Leonard, D; Maranges, C; Fonade, C; Lafforgue, C;
Indirizzi:
Inst Natl Sci Appl, Lab Biotechnol Bioprocedes, UMR CNRS 5504, Lab INRA, F-31077 Toulouse 4, France Inst Natl Sci Appl Toulouse France 4 ab INRA, F-31077 Toulouse 4, France
Titolo Testata:
SEPARATION AND PURIFICATION TECHNOLOGY
fascicolo: 1-3, volume: 22-3, anno: 2001,
pagine: 601 - 615
SICI:
1383-5866(20010301)22-3:1-3<601:HUFCCI>2.0.ZU;2-U
Fonte:
ISI
Lingua:
ENG
Soggetto:
CROSS-FLOW FILTRATION; FLUX ENHANCEMENT; CONTINUOUS FERMENTATION; TUBULAR MEMBRANES; 2-PHASE FLOW; SLUG FLOW; MICROFILTRATION; ULTRAFILTRATION; RECYCLE; ETHANOL;
Keywords:
membrane bioreactor; flow unsteadiness; flux enhancement; gas/liquid transfer; environment;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Engineering, Computing & Technology
Citazioni:
19
Recensione:
Indirizzi per estratti:
Indirizzo: Mercier-Bonin, M Inst Natl Sci Appl, Lab Biotechnol Bioprocedes, UMR CNRS 5504, Lab INRA, 135 Ave Rangueil, F-31077 Toulouse 4, France Inst Natl Sci Appl 135 Ave Rangueil Toulouse France 4 ce
Citazione:
M. Mercier-Bonin et al., "How unsteady filtration conditions can improve the process efficiency during cell cultures in membrane bioreactors", SEP PURIF T, 22-3(1-3), 2001, pp. 601-615

Abstract

Among processes developed to increase biological performances, membrane bioreactors have provided the best results. The membrane bioreactor combines a continuous fermenter and a crossflow filtration module enabling separation of cells from liquid media. Very high biomass concentrations have thus been reached and important bioconversion yields obtained. However the potentiality of this process is mainly limited by the rapid decline in permeate flux due to membrane fouling. In our laboratory, various technological solutions: based on unsteady hydrodynamics inside the tubular filters to limit the external fouling, have been developed and applied during cell cultures inmembrane bioreactors. The biological model was alcoholic fermentation. Thefirst kind of flow unsteadiness was based on an air injection at the membrane inlet to create a gas/liquid slug flow. For the same energy consumption. this process enabled a mean twofold gain in ultrafiltration flux with a lower efficiency for microfiltration due to pore blocking by cell debris. The impact of an unsteady jet generated by a pneumatically controlled valve was also evaluated. Although the strong physico-chemical affinity between the membrane material and the culture medium, a flux enhancement of 1.3 was achieved at the end of fermentation. It was also pointed our that when the formation of a cell cake layer was expected to be the main mechanism for flux decline, flow unsteadiness failed to disrupt a previously built-up deposit and for a maximal efficiency it had to be started at the very beginning of the filtration operation. After these feasibility studies on a relativelysimple and well-known biological model, further applications on environmental problems were carried out. The interest of a gas/liquid slug flow as a means to increase both the permeate flux and the oxygen transfer rate was demonstrated during continuous phenol degradation by Ralstonia eutropha. Theactive biomass could be doubled without encountering oxygen depletion while the permeate flux was 75% higher. This led to the complete degradation ofa high phenol load higher than 70 kg m(-3) day(-1) Finally, a new biological treatment process combining a gas/liquid contactor ('aero-ejector') and a membrane bioreactor was developed in order to ensure total microbial degradation of pollutants which were initially present in industrial gaseous effluents. The 'aero-ejector' technology allowed the solubilisation of gaseous compounds then ethanol) in a liquid phase before their degradation in thebioreactor itself. During aerobic cultures of Candida utilis, almost all injected ethanol was transferred and degraded over 350 h of culture. (C) 2001 Elsevier Science B.V. All rights reserved.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 28/03/20 alle ore 13:58:33