Albumin denaturation during ultrafiltration: Effects of operating conditions and consequences on membrane fouling (original) (raw)
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Journal of Membrane Science, 2000
It was studied how protein-protein and protein-membrane interactions influence the filtration performance during the ultrafiltration of protein solutions over polymeric membranes. This was done by measuring flux, streaming potential, and protein transmission during filtration of bovine serum albumin (BSA) solutions at various pH values using various membranes with different cut-off values.
Journal of Membrane Science
Using matrix assisted laser desorption ionisation mass spectrum (MALDI-MS), this study reports the observations of the fouling distribution and composition along the membrane channel after the membranes were subjected to ultrafiltration of protein mixture solution in a crossflow module with and without spacer. In the fouling layer on a fully retentive membrane, the protein components with high molecular weight has higher presentation after 2 h of filtration and the presentation reduced to be lower than the smaller components after 6 h of filtration due to protein exchange and displacement phenomena in deposition layer caused by the differences in structure and diffusivity of different components. The protein exchange and replacement in the deposition layer was also observed on partial retentive membrane using a sequential fouling procedure. Fouling distribution along the membrane channel with spacer inserted in the module was more uniform and the flux was higher than that without sp...
Desalination, 1993
The application of ultrafiltration and microfiltration to protein solutions is hindered by membrane fouling that results in a decrease in the permeate flux and protein transmission with time. This review describes the evidence for fouling both on the membrane surface and within the membrane pores. The effect of the feed properties, membrane properties and the operating conditions on membrane behaviour and fouling are discussed. In ultrafiltration, fouling occurs predominantly on the membrane surface where the dynamic membrane controls membrane behaviour. In microfiltration, severe pore plugging by protein occurs, in spite of the pores being an order of magnitude larger than the protein.
The Clogging Effect in the Process of Protein Separation by Ultrafiltration
Materiale Plastice, 2020
In this study, five ultrafiltration membranes (polysulfone, cellulose acetate and polyethersulfone) were tested in the treatment of aqueous protein solutions similar to wastewater from fermentation industries. The experiments were made in tangential flow filtration. The permeate flux for the five membranes tested at the optimum pressure of 3 bar decreased due to the effect of clogging the pores by the macromolecular protein solutions. Cellulose acetate membranes showed the lowest permeate flux (Ac-Cel1=152.4 L/m 2 .h and Ac-Cel2=40.3 L/m 2 .h) which doesn't recommend them for the ultrafiltration process of bovine serum albumin. When a polysulfone membrane was used in several cycles of protein-containing wastewater ultrafiltration, the permeate flow decreased progressively from one cycle to another due to the internal clogging of the membrane (501.6 L/m 2 .h up to 444.0 L/m 2 .h). Regarding the ultrafiltration of protein solutions with a suspended yeast content, the clogging was predominant on the membrane's surface, which results in a decrease of the permeate flux by over 50%.
Fouling and Cleaning of Ultrafiltration Membranes in Protein Solution Separation [J]
Ultrafiltration (UF) is one of the best options for both one-stage and as part of multi-stage water and wastewater purification. This review summarises the known facts about the fouling processes and cleaning procedures and details of the most successful physical and chemical cleaning combinations. The optimum cleaning is closely linked to the nature of the fouling. Precise knowledge of both the fouling type (organic, inorganic, or biological) and the fouling mechanism (gel formation, adsorption, deposition, pore blockage, or cake formation) is the key to success in UF membrane cleaning.
Desalination, 2002
Crossflow ultrafiltration of binary protein solutions was carried out using flux-stepping and constant flux experiments to identify the apparent critical flux where fouling is rapid. The contributions of individual protein species to the apparent critical flux were evaluated as well as the separation performance. For mixtures of gðglobulin/lysozyme and BSA/lysozyme the larger retained protein tended to control the critical flux behaviour while the observed rejection of the smaller transmitted protein went through a minimum close to the apparent critical flux. Identification of the respective protein species deposited onto membrane surfaces was carried out using Matrix-Assisted Laser Desorption Ionisation Mass Spectroscopy (MALDI-MS). Mass spectra showed that the transmitted proteins resulted in a higher incidence of peaks relative to the retained proteins. This was thought to be the result of desorption of proteins from the membrane surface, from inside pores and from the membrane substrate. It was shown that the MALDI-MS technique is a powerful tool for distinguishing between different proteins in fouling deposits and has potential for quantitative measurement of protein fouling on membrane surfaces.
Journal of Membrane Science, 2009
Normal-flow filtration is used frequently in the biopharmaceutical industry for applications such as sterile filtration of fermentation media, buffers and product proteins. Though the membrane pores are much larger than the product protein, protein fouling of the membrane often leads to a decrease in permeate flux at constant feed pressure. Normal-flow microfiltration experiments were conducted using polytetrafluoroethylene (PTFE) and polyvinylidene fluoride (PVDF) base membranes, PTFE membranes coated with polyvinyl alcohol (PVA) and Teflon AF, and PVDF and polycarbonate membranes coated with PVA and polyvinyl pyrrolidone.
Analysis of Initial Protein Surface Coverage on Fouled Ultrafiltration Membranes
Journal of Colloid and Interface Science, 1996
brane material for both partially and totally retained mem-Internal surface coverage of protein in membranes during the branes for long-term ultrafiltration (10). Generally it has initial phase of ultrafiltration was analyzed. Bovine serum albumin been found that protein deposition, on the order of 0.5 to (BSA), in solutions of pH 5 and 7 with 0.05 and 0.15 M NaCl, 200 mg/cm 2 , can adsorb on the membrane over a long time were ultrafiltered with 100,000-MWCO polysulfone membranes. (approximately 24 h) (8). This large discrepancy may be Mass uptake of the membranes was determined using electron due to assumptions of nominal surface area being equivalent paramagnetic resonance spectroscopy for separate membranes for to the adsorption area and to error in protein measurement. fractions of an hour for up to 4 h. The resulting data were com-An extensive study that considered the entire membrane area pared with models for surface coverage. The results showed a indicated that near-monolayer adsorption (0.5 mg/cm 2) was significant amount of protein loading exists in a very short time of exposure during ultrafiltration. The amount of material found obtained for bovine serum albumin (BSA) on polyether sulin this period was not a function of solution properties; however, fone membranes during long-term static adsorption (8). solution properties did affect the resistance per mass for adsorbed While studies have concentrated on long-term protein adspecies when the pH was near the isoelectric point of BSA. The sorption studies, only limited research has considered initial modeling comparison implied that the entrained solute from pH adsorption behavior (9-11). Initial studies and understand-7 appeared to behave as though it was lodged in the ultrathin skin ing the dependency of the solute interactions as a function area of the membrane. Solute in the membrane at pH 5 and low of solution properties can provide information on the initial ionic strength appeared to be lodged and adsorbed throughout the steps in the fouling process. However, difficulties in measurmembrane substructure.