To cite this article: Ahmad, A. L. & Mohd Shafie, Z. M. H. (2017). Effect of air gap distance on PES/PVA hollow fibre membrane’s morphology and performance. J. Phys. Sci., 28(Supp. 1), 185–199, https://doi.org/10.21315/jps2017.28.s1.12
New formulation of polyether sulfone (PES)/polyvinyl alcohol (PVA) hollow fibre (HF) membranes were spun at different air gap distances to study the effect on membrane’s morphology and performance. Four different air gap distances (5, 10, 15 and 20 cm) were investigated. The results suggested that air gap played a significant role in determining the circularity of inner lumen and the dimension of the fibres, with oval lumen formed at low air gap of 5 cm and became circular at higher air gap distance. Membrane dimensions were reduced with increasing air gap distance, with the outer diameter shrank from 0.881 ± 0.004 mm at 5 cm air gap down to 0.724 ± 0.008 mm at 20 cm air gap, and inner lumen diameter shrank from 0.564 ± 0.003 mm at 5 cm air gap down to 0.464 ± 0.005 mm at 20 cm air gap. On top of that, the flux and foulant rejection could be altered when using similarly formulated membrane spun at different air gap distance. After 30 min of hydraulic compaction and 1 h of deionised water permeation, maximum water flux was noted at 42.32 ± 0.12 kg/m2.h for HF spun at the air gap of 15 cm. Similar trend was noted after another 1 h of humic acid permeation as model foulant, with maximum flux found at 42.86 ± 0.09 kg/m2.h for the same membrane sample at 15 cm air gap. Nevertheless, rejection was found to be the highest for HF spun at 5 cm air gap with 94.63 ± 2.13% humic acid rejection.