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Effect of soluble calcium of milk on fouling of ultrafiltration membranes
Author(s) -
Rao H G Ramachandra,
Lewis M J,
Grandison A S
Publication year - 1994
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.2740650220
Subject(s) - ultrafiltration (renal) , fouling , membrane , calcium , chemistry , lactose , casein , chromatography , flux (metallurgy) , membrane fouling , chemical engineering , food science , biochemistry , organic chemistry , engineering
Flux decline with time is a major problem encountered during the application of ultrafiltration in the dairy industry. Most work has put the emphasis on the role of casein, whey proteins, fat and colloidal calcium. These components either promote the build up of a concentration polarisation layer or are adsorbed on the membrane surface. The minor constituents have received little attention so far, probably because they do not contribute greatly to the mass of the gel layer. The role of soluble calcium on fouling of membranes is very evident as permeates obtained from four major dairy products fouled the membranes when applied as feed. Ultrafiltration of soft water, mains water and lactose solutions indicated that the presence of calcium brings about flux decline with time. Addition of 2 mM calcium chloride further reduced the flux rates to very low levels but addition of E.D.T.A. to the permeates improved the flux rates and reduced the fouling. Heating the permeates, followed by clarification also had beneficial effects on flux rates.