Resumo (PT):
Abstract (EN):
Characterization of membrane pore size by experimental
methods is usually done by the determination of the rejection of
polymeric molecules having a range of sizes such as PEG. These
experiments are affected by concentration polarization, which can
lead to erroneous interpretation of the results, mainly because the
concentration and the permeate flux change along the membrane
surface. Additionally, experimental methods alone are insufficient
to obtain the membrane pore size. To improve the current
approach, numerical methods are used to understand mass transport limitations in rejection experiments and to predict the membrane pore size. In the current study, the results show that the
ultrafiltration membrane has a MWCO of 20 kDa, different from
the value set by the manufacturer (30 kDa). For the experimental
conditions, concentration dependent viscosity and osmotic pressure do not influence the permeate flow rate or rejection. Moreover, the membrane pore size was found to be 2.59 nm. This value
was determined comparing rejection values obtained by numerical and experimental results. Numerical analysis is also important
to characterize the flow and mass transport in each point at
membrane surface.
Language:
English
Type (Professor's evaluation):
Scientific
Notes:
submitted
No. of pages:
12