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DOI : ,    Vol.21, No.6, 57 ~ 70, 2013
Title
Permeation Behavior of Sucrose Solutions by Forward Osmosis Process
이근우 Keun Woo Lee , 한명진 Myeong Jin Han , 남석태 Suk Tae Nam
Abstract
This study examined the effect of concentration polarization on permeation behavior in forward osmosis membrane process. The membranes used for experiments are commercialized cellulosic membrane(HTI-CAT, Albany, OR). The reduction in permeate flux during a forward osmosis(FO) membrane process is largely due to the formation of concentration polarization on membrane surfaces. The internal concentration polarization within the porous support layer plays more significant role on that reduction compared to the external concentration polarization on the active membrane surface. Water permeate flux through the FO membrane increased nonlinearly with the increase in osmotic pressure. When the draw solution was directed on the membrane active layer(DS-AL), the permeate flux was 1.33-1.90 times higher than that for the draw solution on the support layer(DS-SL). The corresponding variation in the flux would be expressed as J=-0.0177+0.4506π-0.0032π2 for the forward and J=0.0948+0.3292π-0.0037π2 for the latter. The water permeability coefficient was 1.7758x10-7 m/s atm for DS-AL and 1.4481x10-7 m/s atm for DS-SL mode. The corresponding membrane resistance was 5.6312x106 s atm/m for DS-AL and 6.9058x106 s atm/m for DS-SL mode respectively. Mass transfer coefficient was calculated as 0.11x10-6~5.18x10-6 m/s for DS-AL and 0.08x10-6~1.49x10-6 m/s for DS-SL, and the ratio of DS-AL to DS-SL was 1.38~3.48.
Key Words
Forward osmosis, Concentration polarization, Flux decline, Sucrose
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