Investigation of dialysis membrane and seawater desalination brine performance in forward osmosis dewatering of microalgae cultivated in wastewater

Forward osmosis (FO) is drawing attentions for its potential applications in algae-based biofuels and high value-added commodities production. The performance of forward osmosis for dewatering of microalgae cultivated in wastewater was evaluated by using dialysis membrane and seawater desalination brine as draw solution. The microalgae suspension (algae-bacteria consortia) was concentrated from around 1.4 g/L within an hour with brine. The filtration performance was assessed by analyzing water flux behavior and biofouling formation in different time intervals. The green culture of microalgae and bacteria could be osmotically dehydrated at maximum fluxes of around 5.3 LMH in which the fouling not observed significant. As the results shows, seawater reverse osmosis (SWRO) concentrate is strong draw agent for algae dewatering by employing forward osmosis dialysis membrane. This dewatering method was shown to be reliable and cost and energy efficient for algae dewatering application. In addition, this method can be used in conjunction with other dewatering methods to improve biomass recovery process.