Table 1.

The flux of vanillin (Van) and trans-ferulic acid (TFA) at different values of pH. Temperature = 60 °C, permeate pressure = 2 mbar, δ = 60 μm.

pH	Feed concentrations	Flux vanillin	Flux TFA
	ppm	g/(h m2)	g/(h m2)
3	609 Van + 777 TFA	0.64	2.74 × 10−3
4.5	600 Van + 388 TFA	0.64	4.50 × 10−4
7.9	540 Van + 660 TFA	0.28	3.20 × 10−4
10.3	609 Van + 774 TFA	0.01	1.63 × 10−4