THEORY OF CONCENTRATION POLARIZATION IN CROSS-FLOW FILTRATION

Citation
Lf. Song et M. Elimelech, THEORY OF CONCENTRATION POLARIZATION IN CROSS-FLOW FILTRATION, Journal of the Chemical Society. Faraday transactions, 91(19), 1995, pp. 3389-3398
Citations number
13
Categorie Soggetti
Chemistry Physical","Physics, Atomic, Molecular & Chemical
ISSN journal
09565000
Volume
91
Issue
19
Year of publication
1995
Pages
3389 - 3398
Database
ISI
SICI code
0956-5000(1995)91:19<3389:TOCPIC>2.0.ZU;2-A
Abstract
A novel theory is developed for concentration polarization of non-inte racting particles in crossflow-filtration systems. This theory reveals that the extent of concentration polarization, as well as the behavio ur of the permeate flux, are characterized by an important dimensionle ss filtration number (N-F = 4 pi a(p)(3) Delta P/3kT). There is a crit ical value of the filtration number for a given suspension and operati onal conditions. When the filtration number is smaller than the critic al value, a polarization layer exists directly over the membrane surfa ce and the wall particle concentration is determined by the pressure a nd temperature. At higher filtration numbers, a cake layer of retained particles forms between the polarization layer and the membrane surfa ce. Mathematical models are constructed for both cases and analytical solutions for the permeate flux are derived. An increase in permeate f lux with increasing pressure is predicted for all operational conditio ns.