NF-50 composite membrane

A reverse osmosis membrane is commercially available, named NF-40 (FilmTec Corporation), which is closely based on the NS-300 membrane technology. Typical solute rejection data for this membrane are as follows sodium chloride, 45% calcium chloride, 70% magnesium sulfate, 93% sucrose, 98%. Water flux of the membrane averages about 23 gfd at 225 psi and 25°C. As already noted for NS-300, the sulfate anion is associated with high rejection the chloride anion, low rejection. Partial discrimination between monovalent and divalent cations (sodium versus calcium) has also been observed for NF-40. The membrane can be operated at temperatures to 45°C and in a pH range from 3 to 11. In this respect, it would find probable use in industrial separations where 

Among other applications, this membrane is being used in the treatment of salt whey, a waste stream product of cheese making in which the sodium chloride content is very high (up to 7%). The salt whey protein and lactose can be both concentrated and desalted in a single membrane operation (requires some diafiltration). 

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