Nanofiltration Membrane for Organic Acid Concentration and Desalination

Organic acids represented by citric acid, lactic acid and gluconic acid are widely used in food additives, pharmaceutical raw materials and biodegradable polymer industries. Traditional purification routes rely on calcium salt precipitation, acidification and multi-effect evaporation, which bring high chemical consumption, heavy waste residue and high energy input. Nanofiltration, as a pressure-driven membrane process between ultrafiltration and reverse osmosis, possesses selective interception characteristics: it retains organic acid molecules while allowing monovalent inorganic ions to penetrate the membrane. This technology can realize simultaneous concentration and desalination of organic acid fermentation broth under low-temperature conditions, cutting down the consumption of lime and sulfuric acid, and reducing the burden of subsequent evaporation. This article elaborates the separation mechanism, system composition, operating parameters, fouling control and industrial applicatio