정삼투 모듈 성능에 관여하는 영향인자 분석

Abstract

Flat sheet and spiral wound forward osmosis (FO) modules with thin film composite membrane (TFC) were experimented to know the effects of crossflow velocities of feed solution (FS) and draw solution (DS) and concentrations on the performance of the module. An FO module tester was customized for reliable measurements of water flux and reverse solute flux during operation time when the concentration difference between DS and FS was decreased. The test results indicate five cate. First, the water flux and reverse solute flux increases at higher concentration differences between FS and DS. Second the higher crossflow velocity increases water flux by decreasing the effects of external concentration polarization (ECP) Third the pressure differential between the inlet and the outlet of the FO module increases at higher crossflow velocities, which may limit the crossflow velocity in a full-scale FO design. Fourth the flat sheet module shows up to 25 LMH of water flux comparable to the water flux in the coupon tests. At last the spiral wound FO module shows a weird flux pattern in which the increasing rate of water flux becomes retarded when water flux exceeds a critical value maybe because the DS channel in the FO membrane envelop may not allow a flow rate higher than a critical value due to complexity in the DS flow direction.