Nanofiltration membranes were developed in the early 1980s following the typical reverse osmosis composite membranes, which were formerly known as loose reverse osmosis membranes. Nowadays, nanofiltration membrane technology has developed rapidly. At present, nanofiltration membrane technology has become one of the hotspots in the research of drinking water treatment. So, what properties of nanofiltration membrane can be applied to drinking water treatment? Briefly as follows.

1.Softening characteristics: The nanofiltration membrane demineralized water mainly uses the nanofiltration membrane to soften the water by selecting the permeation characteristics of different valence ions. Membrane softening can remove turbidity, color and organic matter while removing hardness, and its effluent quality is obviously superior to other softening processes. Moreover, the nanofiltration membrane softened water has the advantages of non-polluting production, simple operation, and occupational area, and has obvious social and economic benefits.

2.Nanofiltration membrane has certain retention characteristics: the most well-known nanofiltration membrane is used for decolorization in addition to softening in drinking water treatment. The nanofiltration membrane can remove most of the toxic and harmful organic matter and mutagens in water. The interception characteristics of endocrine disrupting substances are obvious, and natural organic substances and synthetic organic substances, three substances, disinfection by-products, precursors and volatile organic substances can be removed. In the direct drinking water of the pipeline, the nanofiltration membrane can retain more than two ions. And other particles, only through water molecules and some monovalent ions.

In addition, the nanofiltration membrane effluent has low corrosiveness, which has a positive impact on the service life of the drinking water pipe network and the dissolution of the pipe metal ions, and is beneficial to the protection of the water distribution system material. Tests have shown that using the best nanofiltration membrane system can reduce the lead content in the pipe network by 50%, while allowing other dissolved metal ion concentrations to meet the drinking water quality standards. Nanofiltration membrane can be used to produce direct drinking water and still retain certain ions in the effluent to ensure the biological stability of drinking water, and provide a basis for safe and quality drinking water. That is to say, by selecting a suitable nanofiltration membrane, the drinking water quality can meet the higher drinking water quality standards.