Pre-treatment

which supplies a stable

high-quality feed for reverse osmosis (RO) membranes

is a critical step for successful operation in a seawater reverse osmosis plant. In this study

ceramic membrane systems were employed as pre-treatment for seawater desalination. A laboratory experiment was performed to investigate the effect of the cross-flow velocity on the critical flux and consequently to optimize the permeate flux. Then a pilot test was performed to investigate the long-term performance. The result shows that there is no significant effect of the cross-flow velocity on the critical flux when the cross-flow velocity varies in laminar flow region only or in turbulent flow region only

but the effect is distinct when the cross-flow velocity varies in the transition region. The membrane fouling is slight at the permeate flux of 150 L穖

-2

穐

-1

and the system is stable

producing a high-quality feed (the turbidity and silt density index are less than 0.1 NTU and 3.0

respectively) for RO to run for 2922.4 h without chemical cleaning. Thus the ceramic membranes are suitable to filtrate seawater as the pre-treatment for RO.