NANOFILTRATION
• less pore sizes than ultrafiltration
membranes
• the mass transfer mechanism is diffusion &
separate small molecules from the solution
(assymmetric)
• cellulosic acetate and aromatic polyamide
type membranes (salt rejections; 95% for
divalent salts to 40% for monovalent salts)
• can typically operate at higher recoveries;
conserving total water usage due to a lower
concentrate stream flow rate (advantage
over reverse osmosis)
• not effective on small molecular weight
organics (e.g.methanol)