SODIUM HYPOCHLORITE PRODUCTION FROM SALTED GROUNDWATER
LEONID SOKOLOV *
Vologda State University, Lenina Street 15, Vologda, 160000, Russia.
VIKTOR SILINSKIY
Vologda State University, Lenina Street 15, Vologda, 160000, Russia.
SVETLANA KOLOBOVA
Vologda State University, Lenina Street 15, Vologda, 160000, Russia.
*Author to whom correspondence should be addressed.
Abstract
This paper considers the production of low-concentration sodium hypochlorite intended for disinfection of drinking water by direct electrolysis of natural salted groundwater. The use of mineralized groundwater as an electrolyte makes it possible to eliminate the stage of artificial preparation of chloride solution. This simplifies the technology of disinfectant production and reduces operating costs. The optimal electrochemical parameters of the electrolysis unit operation and the service life of electrodes were determined. Established were the technological parameters of the electrolysis unit operation on salted groundwater, namely the initial concentration of chlorides, the anode current density, the material of electrodes, and the duration of electrolysis. The mechanism of sodium hypochlorite decomposition was studied as a function of pH value, temperature, and shelf life. It was found that for higher initial concentrations the concentration of the resulting hypochlorite decreases significantly with time. It was confirmed that electrolysis of weakly concentrated sodium chloride solutions of 1.5-15 g/l is energetically favourable, while the change in the polarity of the electrodes ensures the removal of cathode deposits and increases the efficiency of the process of obtaining sodium hypochlorite from natural mineralized waters.
Keywords: Direct electrolysis, disinfection, low-concentration sodium hypochlorite, natural salt water, water treatment