Protein Adsorption and Deposition onto Microfiltration Membranes: The Role of Solute-Solid Interactions.
The mass of gamma-globulin fouling an Anodisc alumina membrane with a nominal pore diameter of 0.1 µm has been measured at several concentrations and pHs. This fouling resulted from filtering through the membrane in a continuous recirculation device. The low-concentration fouling can be attributed mainly to adsorption. The complete concentration dependence of fouling mass has been obtained and fitted to a Freundlich heterogeneous isotherm, from which the pH dependence of active fouling sites and energies has been also obtained. Adsorption is studied as a function of the electrostatic forces between the solute and the membrane. A sharp maximum in the adsorbed mass for zero electrostatic force is observed. At high concentrations, accumulation plays a relevant role at alkaline pH, as confirmed by flux decay experiments, retention measurements, and AFM (atomic force microscopy) pictures. Copyright 2000 Academic Press.
Martínez
F
Depto. Termodinámica y Física Aplicada, Fac. Ciencias, Universidad de Valladolid, Valladolid, 47071, Spain
Martín
A
Prádanos
P
Calvo
JI
Palacio
L
Hernández
A