Table 2.

Properties of the NF membranes were applied.

	NFX 1	NFDL 1	NF270 1
Supplier	Synder Filtration	Suez	Dow FilmTec
Maximum Operating Temperature, °C	50	50	45
pH range	3–10.5	3–9	2–11
Minimum MgSO4 rejection, %	99	96	99.2
Membrane material	Polyamide thin-film composite	Polyamide thin-film composite	Polyamide thin-film composite
Isoelectric point	3.2	4	3.0
Molecular weight cut-off, Da	150–300	150–300	200–400
Average pore width, nm	n/a	9.6 [18]	7.9 [18]
Contact angle, °	n/a	37.9 [18]	15.9 [18]

¹ Test conditions according to membrane supplier information: 2000 ppm MgSO₄ inlet solution at 110 psi (760 kPa) operating pressure, isothermal process conditions at 77 °F (25 °C), tests at 15% permeate recovery after 24 h of filtration.