The nanofiltration membrane has a pore diameter of 1 nm or more, generally 1-2 nm. It is a functional semipermeable membrane that allows solvent molecules or certain low molecular weight solutes or low-priced ions to pass through. It is a special and promising type of separation membrane. Because the size of its trapped substances is about nanometer, it is called Nanofiltration membrane. Its molecular weight of intercepted organic matter is about 150-500, and the ability to retain soluble salts is 2- Between 98%, the desalting of the monovalent anion salt solution is lower than that of the high-valent anion salt solution. It is used to remove organic matter and chromaticity of surface water, remove the hardness of groundwater, partially remove dissolved salts, concentrate juice, and separate useful substances in medicines.

Advantage of Nanofiltration membrane:

1. Concentration and purification process is carried out at room temperature, no chemical reaction, no other impurities and decomposition and denaturation of the product, especially suitable for heat sensitive substances.
2. It can remove the salt of the product, reduce the ash of the product and improve the purity of the product. Compared with the solvent desalting, not only the product quality is better, but also the yield can be improved.
3. High process yield and low loss 4. Recyclable acid, alkali, alcohol and other effective substances in the solution to achieve recycling of resources
4. Compact structure, small footprint and low energy consumption
5. Easy to operate, automatic operation, good stability and easy maintenance