Ultra Pure Water
Ultra
pure water is mainly used in the semi conductor and pharmaceutical industry. Because
of the continuing miniaturilisation in the semi conductor industry, the specifications
become more strict every year.
Ultra-pure water contains by definition only H20, and H+ and
OH- ions in equilibrium. Therefore, ultrapure water conductivity is about
0,054 uS/cm at 25oC, also expressed as resistivity of 18,3 MOhm.
Ultrapure water production often has to be done in 2 steps. For example, from tap
water or fresh groundwater, the water should first be demineralised by membrane
filtration or ion exchange to reach the ultimate conductivity of 10 uS/cm.
The demineralised water is then processed through a high performance Mixed Bed or
by Electrodionisation.