Table 1.

Correlation between the surface roughness of commercial RO/NF membranes and their relative fluxes for the filtration of a 0.05 M NaCl solution containing 200 mg/L silica particles (0.10 µm); pH = 6.8. Flux-decline values determined for 10 L of permeate volume filtered *.

Membrane Type	Flux Decline, J/J◦, %	Average Roughness, nm	RMS Roughness, nm
Osmonics HL	13.9	10.1	12.8
Trisep X-20	38.3	33.4	41.6
Dow NF-70	46.9	43.3	56.5
HydranauticLFC-1	49.3	52.0	67.4

* Adapted with permission from [40].