Harvesting Nannochloropsis sp. using PES/MWCNT/LiBr membrane with good antifouling properties

Abstract

One of the greatest challenges to maintain sustainability in algae-based biorefinery is an effective harvesting process. Membrane filtration has become one of the methods for microalgae harvesting due to its versatility in separation. However, membrane fouling which arises from the interaction between algae cell and membrane surface significantly impedes the efficient application of the membrane technology. Thus, this paper reports on the feasibility of microalgae harvesting using good anti fouling PES membranes. The antifouling PES membranes were fabricated using multiwall carbon nanotubes (MWCNT) and lithium bromide (LiBr) as additives in dimethylacetamide (DMAC). Our results revealed that membrane fabricated with 1 wt% MWCNT, 5 wt% LiBr and 18 wt% PES via thermally induced phase separation (TIPS) process possessed an excellent filtration performance and anti-fouling effect. 28 g/l Nannochloropsis sp. have been fully retained using the fabricated membrane with average flux 28.9 L/m2h. Furthermore, the membrane demonstrated excellent anti-fouling effect owing to its higher membrane hydrophilicity indicated by the low contact angle value of 33.8°. Durability study performed exhibited 100% flux recovery rate after rinsing with tap water. The membrane demonstrated no fouling detrimental effects even after five cycles via consistent flux.