ISSN:
0021-8995
Schlagwort(e):
Chemistry
;
Polymer and Materials Science
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
,
Maschinenbau
,
Physik
Notizen:
The ultrafiltration process was modelled in three separate stages with distinctive time constants. It was shown that in the first stage lasting less than 5 s a quasi-steady-state concentration profile is reached on the membrane/solution interface. In the second stage of 1-10-min solute adsorption on the membrane surface including the pores controls the permeation rate. The third stage is governed by a reaction mechanism which produces a surface gel causing flux decline at a slower rate than in the previous adsorption step. This polymerization of the protein to a gel on the membrane was shown to be second order in the interface protein concentrations. A reproducible and inexpensive method has been developed to attach food-grade proteases onto UF membranes by producing a primary adsorbed layer of enzyme which then retards the rate of gel formation on the ultrafilter. This resulted in 25-78% improvement in cumulative permeate yield in a standard 22-h run when processing 0.5% albumin or hemoglobin. The enhanced fluxes with self-cleaning membranes were modelled by incorporating an enzyme activity term to counteract the deposition of gel on the membrane surface and altering the apparent order of the gelation reaction.
Zusätzliches Material:
5 Ill.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/app.1982.070270103
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