For NF membranes (MWCOb1 kDa), the measured permeate
fluxes plotted against applied transmembrane pressure are presented
in Fig. 4. For all membranes tested, permeate flux increased steadily
with transmembrane pressure. However, for the DK and DL
membranes from GE Osmonics, the permeate flux tended to reach a
maximum with transmembrane pressure at 2.5 MPa or higher.
Compaction also seems to have occurred in these membranes.
Overall, Dow (NF-) and GE Osmonics membranes (DL and DK)
presented the highest permeate fluxes. Membranes DL and DK, with a
permeate flux of about 40 kg h−1 m−2, presented the highest fluxes,
whereas membrane NP030 from MICRODYN-NADIR yielded the
lowest permeate flux at 5.75 kg h−1 m−2.