Modeling colloid deposition on a protein layer adsorbed to iron-oxide-coated sand

Author(s)
Thilo Hofmann, Frank von der Kammer, Xinyao Yang, Ray Flynn
Abstract

Our recent study reported that conformation change of granule-associated Bovine Serum Albumin (BSA) may influence the role of the protein controlling colloid deposition in porous media (Flynn et al., 2012). The present study conceptualized the observed phenomena with an ellipsoid morphology model, describing BSA as an ellipsoid taking a side-on or end-on conformation on granular surface, and identified the following processes: (1) at low adsorbed concentrations, BSA exhibited a side-on conformation blocking colloid deposition; (2) at high adsorbed concentrations, BSA adapted to an end-on conformation promoted colloid deposition; and (3) colloid deposition on the BSA layer may progressively generate end-on molecules (sites) by conformation change of side-on BSA, resulting in sustained increasing deposition rates. Generally, the protein layer lowered colloid attenuation by the porous medium, suggesting the overall effect of BSA was inhibitory at the experimental time scale. A mathematical model was developed to interpret the ripening curves. Modeling analysis identified the site generation efficiency of colloid as a control on the ripening rate (declining rate in colloid concentrations), and this efficiency was higher for BSA adsorbed from a more dilute BSA solution.

Organisation(s)
External organisation(s)
Sichuan Agricultural University, Queen's University Belfast
Journal
Journal of Contaminant Hydrology
Volume
142-143
Pages
50-62
No. of pages
13
ISSN
0169-7722
DOI
https://doi.org/10.1016/j.jconhyd.2012.09.006
Publication date
2012
Peer reviewed
Yes
Austrian Fields of Science 2012
105303 Hydrogeology, 104023 Environmental chemistry, 105105 Geochemistry, 105904 Environmental research
Portal url
https://ucrisportal.univie.ac.at/en/publications/c53d6bb9-04a5-4663-8594-8b8f623cc05f