S. Okouchi et al., RELATIONSHIP BETWEEN WATER QUALITIES AND TREATMENTS IN THE ULTRA-PUREWATER PRODUCTION SYSTEM, Water science and technology, 30(10), 1994, pp. 237-241
Citations number
5
Categorie Soggetti
Water Resources","Environmental Sciences","Engineering, Civil
In an ultra pure water (UPW) production system which can satisfy the w
ater qualities for 4 megabit DRAM, the changes in water qualities from
a tap water(58.4 mg/dm(3) as CaCO3, hardness) as a raw water to UPW w
ere followed from the view of the micro-structure and microdynamic beh
avior of water molecules with increasing of the water purity by a comp
lex permittivity and O-17-NMR measurements, as well as measurements of
resistivity, density, and so on. The dielectric relaxation time and s
pin-lattice relaxation time of O-17 nuclei related to the microdynamic
behavior of water molecules indicated a trace change between the tap
water and UPW. However, the dielectric parameter alpha which character
izes a symmetric distribution of relaxation times was gradually lowere
d with increasing of the water purity, The relationship between the ha
lf-width of O-17 magnetic resonance and pH gave the rate constants for
the prototropic charge migration in water, The difference of alpha an
d density between the tap water and UPW became a measure of water puri
ty.