Special Applications of Nanofiltration Membranes

Nanofiltration membranes have established itself as a mainstay in many applications involving drinking water and beverage manufacturing. However, their use in other special applications is not often discussed in literature. This study takes on the challenge of applying commercial nanofiltration membranes for various separation/concentration processes with growing commercial interest. NE70 (Toray Chemical CSM) nanofiltration membrane reduced COD and BOD found in landfill leachate treatment water from 5,400ppm to 180ppm and 3,400ppm to 50ppm respectively. Polysaccharides with low conductivity were concentrated to over 80% by using NE40 and 70 membranes. Raw materials used in the cosmetics industry were concentrated using NE70 membranes with significant energy savings as compared to traditional thermal fractionation techniques. In order to recover valuable ions found in the chlor-alkali wastewater, NE70 membranes were used to selectively separate out sulfate (SO42-) ions. NE70 membranes were also used to effectively separate lithium ions from other multivalent species for battery manufacturing processes. And last, nanofiltration membranes were applied to concentrate glyphosates, most often used in pesticides, from 0.1% up to 2.5% via a membrane de-watering process.