In this paper the behavior of two UF membranes has been evaluated
in terms of fouling after BSA solution filtration and in terms
of cleaning with two cleaning solutions (NaOH and P3 Ultrasil
115). It can be concluded that fouling of the UH030 membrane
was higher than the UP005, what can be explained both by the different
membrane pore size and by characteristics of the membranes
such as contact angle, zeta potential and roughness.
Fouling was mainly reversible for both membranes, since membrane
resistances calculations showed a higher reversible resistance
than the irreversible one. The irreversible resistance was
totally eliminated by P3 Ultrasil 115 in the tested conditions;
meanwhile CE of the membranes after cleaning with NaOH at a
temperature of 45 C was between 80% and 90%.
Almost complete restoration of the initial flux and high values
of cleaning efficiency (100%) with the P3 Ultrasil 115 solution did
not imply the complete removal of BSA from the membrane as
detected by the FTIR–ATR and Pierce-BCA methods after extraction.
Thus, this kind of analysis can become an important tool to
study membrane cleaning together with the well known study of
the membrane in series resistances. In fact, non-eliminated BSA
can favour membrane fouling by attachment of BSA of the feed
solution on the previously deposited protein molecules.