Sk. Karode, Unsteady state flux response: a method to determine the nature of the solute and gel layer in membrane filtration, J MEMBR SCI, 188(1), 2001, pp. 9-20
The unsteady-state permeate flux response to a step change in transmembrane
pressure is shown to result in unique flux-pressure profiles for the three
types of solutes common in membrane ultrafiltration (UF): (a) solutes whic
h exert an osmotic pressure but do not form a 'gel'; (b) solutes which do n
ot exert an osmotic pressure but form a 'gel' and (c) solutes which exert a
n osmotic pressure and also form a 'gel'. It is also shown that for stirred
cell UF, changes in the bull; feed solution properties (concentration, vol
ume) are negligible on the time scale needed to attain a stable permeate fl
ux. Unsteady-state permeate flux measurements could therefore be made at sh
ort filtration times so that the results would not be mashed by changes in
bulk properties. (C) 2001 Elsevier Science B.V. All rights reserved.