Dewatering of microalgae suspension using air-sparged ultrafiltration

Dewatering is one of the bottlenecks in microalgae-based biofuel production. Ultrafiltration is a scalable and chemical additive-free dewatering technique. In this paper, we examine air-sparging for mitigating the problem of microalgae cake formation during ultrafiltration. The extent of cake formation was assessed and its detrimental effect on filtration performance was quantified. Our results indicated that microalgae cake-layer formation could be inhibited by gas-sparging, the effects of which were observed as enhancement in a permeate flux and biomass recovery. These improvements were found to be linked to the intensity of gas-sparging as well as the design of the ultrafiltration device.