Chlorella vulgaris broth harvesting via standalone forward osmosis using seawater draw solution

Abstract

Microalgae biomass gains interests for its promising sustainability as feed-stock in biofuels production. However, high-energy cost for biomass cultivation and harvesting must substantially be reduced to enhance its viability. This study evaluates the application of standalone forward osmosis (FO) and aeration as fouling control for Chlorella vulgaris dewatering using seawater as draw solution (DS). Overall results reveal the feasibility of using seawater as DS and aeration for membrane fouling control. Application of seawater as the DS offers desirable performance as it produces high water fluxes (>6 L/m2 h) at volumetric concentration factors of up to 6×. The air bubbling significantly increases the flux even at low rates by up to 67%. The proposed system is suitable for handling freshwater microalgae, especially when farmed near the seashore. Technoeconomic analyses and implementation optimization of proposed study are important to gauge its true potential and feasibility, thus will be subjected to future study.