Effects of Acid-fermented Food Wastewater in Microwave-based Direct Lipid Extraction from Wet Microalgae

This study examines two methods to enhance the efficiency of microwave (MW)-based lipid extraction from wet microalgae. The first method involved optimizing the MW conditions based on the energy efficiency, moisture contents of microalgae, MW power, and target temperature. The second was the application of food wastewater (FWW) as an ionic material and alternative solvent to increase the energy and cost efficiencies. The optimal conditions were an 83% moisture content, 400 W MW power, and 90°C target temperature. The addition of FWW improved the energy efficiency 1.4-fold compared to that without the addition of FWW. On the other hand, acid-fermented FWW had no significant effect as a polar solvent because of the high moisture content. Overall, optimization of the MW conditions and FWW addition could enhance the lipid extraction yield and energy efficiency.