Reverse osmosis equipment is called RO equipment for short, and its filtration accuracy is 0.000 1 micron. Reverse osmosis technology is the most selected membrane separation technology in the world at present, which can effectively block all soluble salts and organic substances with molecular weight greater than 100, but allow water to penetrate. The desalination rate of reverse osmosis composite membrane is generally greater than 98%.
Nanofiltration equipment is called NF for short. Nanofiltration is a special and promising membrane separation equipment. The size of the intercepted substance is about 0.00 1 micron. The operating pressure of nanofiltration is between ultrafiltration and reverse osmosis equipment. The molecular weight of the intercepted organic matter is about 200~400, and the ability to intercept soluble salts is 20~98%. The desalination rate of monovalent anion salt solution is higher than that of multivalent anion salt solution.