Nanofiltration-membrane technique and its application

Nanofiltration is a pressure-driven membrane-separation technique similar to reverse osmosis filtration and ultrafiltration. In this paper, the mechanisms of nanofiltration are discussed in brief and relevant mathematical models, such as the space charge model, the fixed charge model, the e1ectrostatic and steric-hindrance mode1, and Donnan-steric pore model, are described. Applications of nanofiltration membranes in water treatment, pharmaceutical industry, food and dye industries etc. are reviewed. In addition, future prospects on the development of nanofiltration are presented.