University of Surrey

Test tubes in the lab Research in the ATI Dance Research

Solubility of Calcium Phosphate in Concentrated Dairy Effluent Brines

Kezia, K., Lee, J., Zisu, B., Chen, G. Q., Gras, S. L. and Kentish, S. E. (2017) Solubility of Calcium Phosphate in Concentrated Dairy Effluent Brines Journal of Agricultural and Food Chemistry, 65 (20). pp. 4027-4034.

[img]
Preview
Text
The solubility of calcium phosphate - AAM.pdf - Accepted version Manuscript

Download (587kB) | Preview

Abstract

The solubility of calcium phosphate in concentrated dairy brine streams is important in understanding mineral scaling on equipment, such as membrane modules, evaporators, and heat exchangers, and in brine pond operation. In this study, the solubility of calcium phosphate has been assessed in the presence of up to 300 g/L sodium chloride as well as lactose, organic acids, and anions at 10, 30, and 50 °C. As a neutral molecule, lactose has a marginal but still detectable effect upon calcium solubility. However, additions of sodium chloride up to 100 g/L result in a much greater increase in calcium solubility. Beyond this point, the concentrations of ions in the solution decrease significantly. These changes in calcium solubility can readily be explained through changes in the activity coefficients. There is little difference in calcium phosphate speciation between 10 and 30 °C. However, at 50 °C, the ratio of calcium to phosphate in the solution is lower than at the other temperatures and varies less with ionic strength. While the addition of sodium lactate has less effect upon calcium solubility than sodium citrate, it still has a greater effect than sodium chloride at an equivalent ionic strength. Conversely, when these organic anions are present in the solution in the acid form, the effect of pH dominates and results in much higher solubility and a calcium/phosphate ratio close to one, indicative of dicalcium phosphate dihydrate as the dominant solid phase.

Item Type: Article
Divisions : Faculty of Engineering and Physical Sciences > Chemical and Process Engineering
Authors :
NameEmailORCID
Kezia, K.
Lee, J.j.y.lee@surrey.ac.uk
Zisu, B.
Chen, G. Q.
Gras, S. L.
Kentish, S. E.
Date : 24 May 2017
DOI : 10.1021/acs.jafc.6b05792
Copyright Disclaimer : © 2017 American Chemical Society
Uncontrolled Keywords : Calcium phosphate; Dairy; Brine; Solid phase equilibria; Lactate; Citrate
Depositing User : Clive Harris
Date Deposited : 30 Jul 2020 15:23
Last Modified : 30 Jul 2020 15:23
URI: http://epubs.surrey.ac.uk/id/eprint/858330

Actions (login required)

View Item View Item

Downloads

Downloads per month over past year


Information about this web site

© The University of Surrey, Guildford, Surrey, GU2 7XH, United Kingdom.
+44 (0)1483 300800