Abstract
Corrosivity of vapor-phase environments in indoor pool, water tank, and water purification plants was investigated. Sodium hypochlorite (NaClO) was used as a sterilizing agent in indoor pool, while chlorine gas was used in water tank and water purification plants. It was found that Cl- ion were concentrated in the dew formed in the indoor pool. H+ ions as well as Cl- ions were accumulated in the dew formed in the water tank and water purification plants. Thus, the corrosion conditions was varied with the type of sterilizing agents used. Through the investigation of water tank, the relationship between pH and Cl- ion concentration was given as follow;
pH=-1.09-2.19log[Cl-] (mol/L).
Corrosivity of vapor-phase environments in sterilizing water systems would be characterized by the existence of oxidizing chemical agents such as ClO- and HClO, the shift of corrosion potential of the thin water film, and the accumulation of H+ and/or Cl- ions in the dew.
