Treatment of Fermented Broth for Recovery of Organic Acid Using Integrated Membrane

During biomass (e.g., crops, animal residues, food waste) decomposition under an aerobic fermentation process, organic acids such as acetic acid and butyric acid are continuously produced from controlled microbial activity. Since the accumulation of organic acids hinders the microbial metabolism in the fermentation broths, the organic acids should be removed by using appropriate separation processes. The integrated membrane processes proposed here, including the three steps of (1) clarification of fermentation broth, (2) organic acid separation, and (3) dewatering, can be applied to achieve energy-efficient and environmentally friendly organic acid removal and recovery. First, clarification steps using microfiltration or ultrafiltration processes. In this study, we focused only on organic acid separation and dewatering processes using nanofiltration and forward osmosis membrane processes. Finally, a low-energyconsuming forward osmosis process was applied for dewatering in the aqueous organic acid to obtained concentrated organic acid.