Water Disinfection with Weak Sodium Hypochlorite at Water Supply Stations of St. Petersburg

Summary

The method of water disinfection with sodium hypochlorite produced from common salt solution using the electrolysis method at the place of use has been introduced at two largest water supply stations, Southern and Northern, of St. Petersburg. The use of sodium hypochlorite of low concentration makes it possible to avoid the necessity of transportation and long-term storage of a ready solution. The technology introduced makes it possible to minimize considerably the risk existing in the case of the use of liquefied chlorine and reduce the operation expenses comparing with strong solutions of sodium hypochlorite.

Key words:

disinfection , sodium hypochlorite , weak solution , electrolysis , common salt , softened water , process automation