Disinfection of water with low-concentration sodium hypochlorite

Summary

An advanced safe technology for the production of low-concentration sodium hypochlorite from salt brine is considered. The main stages of the technological process are described in detail. Particular attention is paid to the issues of industrial safety and reliable operation of electrolyzers – units for the preparation of sodium hypochlorite at the Southern and Northern water treatment facilities of SUE «Vodokanal of St. Petersburg». The use of low-concentration solutions of sodium hypochlorite provides for improving the safety of water purification processes. Salt is the raw material for the production of sodium hypochlorite. Since the chemical is used directly at the place of production, there is no need for transportation. The combination of disinfection of treated water with low-concentration sodium hypochlorite (first stage) with ultraviolet irradiation (second stage) before supplying it to the city water supply network guarantees full compliance of water quality in terms of microbiological indicators with current standards and its high epidemiological safety.

Key words

disinfection , water treatment , sodium hypochlorite , epidemiologic safety

GRUNDFOS solutions for disinfection of water and effluents

Summary

The SARS-CoV-2 pandemic has revealed many problems in the epidemiological safety systems of almost all countries of the world. GRUNDFOS has developed a wide product line that can be used as part of integrated solutions for establishing local water treatment systems, as well as for disinfecting closed public water supply systems. Among them are Smart Digital metering pumps, that ensure the high metering accuracy and the ability to finely control the concentration of dosed chemicals, as well as the solutions for the disinfection of public water supply systems – GRUNDFOS Selcoperm electrolysis units and GRUNDFOS Vaccuperm industrial chlorination units. Selcoperm units provide for producing sodium hypochlorite directly at the point of use. Vaccuperm is a vacuum dosing system that disinfects water with gaseous chlorine.

Key words

electrolyzer , epidemiologic safety , local water treatment systems , disinfection of public water supply systems , dosing pump