Table 1. Spinning conditions of the various double layer membranes.

	M 1	M 2	M 3	M 4	M 5	M 6
Inner layer (PES/PVP)	15/5	15/7	15/10	15/10	15/7	15/7
Outer layer (PES/PVP/AC)**	14/1.4/37.5	14/1.4/60	14/1.4/60	14/1.4/60	14/1.4/60	14/1.4/60
Inner layer pumping speed (ml/min)	0.5	0.4	0.4	0.4	0.4	0.4
Outer layer pumping speed (ml/min)	1	1.6	2	1.6	1.6	1.6
Bore liquid pumping speed (ml/min)	1.2	1.2	2	2	1.2	1.2
Bore composition*	B1	B1	B2	B2	B2	B1
Air gap (cm)	15	15	10	10	10	10
Spinneret type	Spinneret 2.0	Spinneret 2.0	Spinneret 2.0	Spinneret 2.0	Spinneret 2.0	Spinneret 2.0
Collecting speed (m/min)	Free fall	Free fall	Free fall	Free fall	3.5	3.5

^*Bore liquid B1 consists of pure water and the bore liquid B2 contains 60% NMP and 5% PVP in pure water.

^**Amount of activated carbon was calculated in relation to the amount of PES.