Energy Reduction in Ceramic Microfiltration using Carbon-Dioxide-Enhanced Backwash

Supersaturated carbon dioxide solution was applied to backwash ceramic membranes. Three types of feed water were employed with the filtration of three membranes with different serving time. CO2 backwash had a lower average TMP of backwash, leading to higher flux. The increment TMP of filtrations before and after CO2 backwash was lower than DI water backwash, which indicated higher cleaning efficiency of CO2 backwash. Energy was saved from 0.7% to 17% with CO2 backwash comparing with DI water backwash before it. The CO2 backwash showed a better cleaning efficiency than DI water backwash because higher shear stress was provided during the backwash when carbon dioxide gas came out from the supersaturated solution.