Investigation of the effect of changes in the ion composition
of water on the zeta-potential and redox potential

Summary

The results of studies of drinking water in the public water supply system of the city of Samara are presented. While determining the organoleptic indicators of the water quality, an increase in color of the initial samples by 1–3 degrees within the procedural error was revealed. This may be due to the high concentration of iron and its compounds or humic substances in the samples on the days of the experiment, as well as to the high physical deterioration of the water distribution networks (both street networks and plumbing in the buildings), and the general increase in water color in the Saratov water reservoir in the city of Samara in recent years. The dependence of the ζ-potential on the redox potential value and ion composition of water is established. The physicochemical composition of the studied water is determined, an analysis of the results is carried out. In the course of the research, such indicators as pH, temperature, turbidity and alkalinity were additionally determined to obtain an aggregate picture of the water quality. The compliance of all studied water indicators with the requirements of SanPiN 2.1.4.1074-01 «Drinking water. Hygienic requirements for water quality of centralized drinking water supply systems. Quality control» was confirmed. Mathematical dependences between the ζ-potential, hardness, and the concentration of anions and cations in the water under study are given with an approximation authenticity R2 higher than 0.83. This allows calculating the ion composition and turbidity of drinking water in Samara only by the value of the ζ-potential or redox potential without expensive labor-intensive chemical analyzes. The proposed method is recommended to be used as an express analysis of drinking water.

Key words

water quality , ζ-potential , ion composition of water , salt concentration , redox potential