As seen from Fig. 5, clear differences were observed between
the surface morphologies of the clean and fouled membranes. The
pollutants accumulated on the surface of the FM NP010 membrane
at all transmembrane pressures. The membrane fouled at 36 bar
(Fig. 5(b)) exhibited a relatively rough surface than that of 12 bar
because of more pollutants accumulated on the membrane surface
at 36 bar.