Pure water, also known as purified water, is a type of colorless transparent drinkable water which sealed up in container meanwhile it does not have any additives. It is made from raw water which accords with drinking water standards by process methods of electro-dialysis, ion exchange, RO, distillation and others.
Most space water, distilled water in markets belong to pure water. The strong and weak electrolyte in raw water, e.g.: SiO2, CO2, etc. are removed to some extent degree. Its conductivity usually is 1.0-0.1μs/cm, resistivity 1.0-10.0MΩ•cm, saltiness<1mg/L.
Ultra-pure water is made on the basis of pure water by further removing almost all conducting medium, meanwhile removing non-dissociative colloidal substance, air and organics to lowest extent degree. Resistivity is above 18.0MΩ•cm or close to extreme 18.25MΩ•cm.
Ultra-pure water is hard to achieve through ordinary process, it can be realized by two or more techniques among micro-filtration, ultra-filtration, RO, EDI and ion-exchange along with rational process designation, equipment selection, to achieve ultra-pure water with resistivity 18.20MΩ•cm odd.
The difference between pure water and ultra-pure water exists in various aspects, we sum up it as follows:
- Conductivity: pure water is normally between 2-10μs/cm, and ultra-pure water 0.056μs/cm.
- Production process: the pure water applied in markets normally is made by the way of RO and distillation, but on the basis of pure water, we also need photo-catalytic oxidation, fine treatment, and other series of complicated purifying method to achieve.
- Quality standard in heavy metal, virus, particle: pure water is PPM grade and ultra-pure water PPB grade. In short, ultra-pure water almost has no foreign substances and approach to theoretical water.
- Different application industries.
- The material of transportation pipe: the pipe for transporting ultra-pure water is stricter than that for pure water.
