Feasibility of Producing Sodium Hypochlorite for Disinfection Purposes using Desalination Brine

Abstract

On the Fernando de Noronha archipelago of northeast Brazil, the water supply comes from the desalination of seawater. The main environmental problem related to desalination is the brine resulting from the process, comprised of highly concentrated salts. The present study aimed to produce oxidant solutions from brine for disinfection purposes. The experiment was carried out on a laboratory scale. The brine had a chloride concentration of 40000 mg/L. The electrolysis process lasted twenty-four hours, monitoring pH, electrical conductivity, temperature, and chlorine. The sodium hypochlorite production was 2.27% and 3.61% m/m. The oxidant solutions were tested on domestic effluents and achieved a 99.99% removal rate of thermotolerant coliforms while maintaining the concentration of organochlorines below the upper limit established by legislation for the disposal of effluents. Therefore, the use and more proper brine disposal are sustainable alternatives, enabling the on-site production of sodium hypochlorite on the archipelago in a safe, effective, reliable way and comparable to other oxidants.