A m	membrane area (m2)
a w	activity of water (-)
B w	water vapor permeability (s/m)
c f	salt concentration in the feed (kg/m3)
c f,0	initial feed concentration (kg/m3)
c p	permeate concentration (kg/m3)
c p,distill	salt concentration in the distilled water (kg/m3)
c p,leak	salt concentration in the water leakage (kg/m3)
c p,net	salt concentration of the water transferred through the membrane (kg/m3)
D e	specific gravity of the ethanol (g/cm3)
D p	specific gravity of the PVDF material (g/cm3)
J v	permeate (water) flux (kg/m2-h)
L w	leakage ratio (-)
m 1	mass of the saturated membrane (g)
m 2	mass of the dry membrane (g)
p w	vapor pressure (bar)
R app	apparent salt rejection (-)
R int	intrinsic rejection (-)
subscript f	feed
subscript p	permeate
superscript 0	pure water
x NaCl	mole fraction of NaCl (-)
x w	mole fraction of water (-)
Δmg	increased mass of the permeate (g)
Δpw	vapor pressure difference (bar)
Δt	time interval (s)
γ	activity coefficient (-)
γ w,f	activity coefficient of water in the feed (-)
ρ	density of water (kg/m3)