INVESTIGATION OF WATER DISINFECTION PROCESSES USING PULSE ELECTRIC DISCHARGE

Abstract

As a result of Russian military aggression in the south-eastern region of Ukraine, water supply pipes and structures of centralized water supply systems were destroyed, and therefore water supply was practically stopped. The solution to the problem can be the use of mobile water treatment stations which use local sources of water: canals, lakes, ponds, or underground water. A feature of water treatment technologies in the field is the need to reliably ensure the process of water disinfection. Existing water disinfection technologies have low efficiency, taking into account the growing number of chlorine-resistant microorganisms, therefore, the implementation of alternative methods of disinfection during water treatment is urgent. One of these methods is liquid disinfection by electric current discharge. The results of the research on disinfection of different types of surface water in Kyiv and water contaminated with E. coli (Escherichia coli (E. coli)) are described. The research was carried out on a laboratory setup with a circulation pump and an ejector-type reactor with integrated electrodes where a water-air mixture is formed through which an electric discharge passes. The discharges initiate the formation of various highly reactive chemicals such as radicals (OH•, H•, O•) and molecules (H2O2, H2, O2, O3). All physical and chemical processes that occur during discharge ensure the formation and action of short-term radicals and relatively long-term oxidants. The study of the influence of the concentration of microorganisms on the speed and completeness of water disinfection was carried out on technical (tap) water with the addition of washings from two tubes with test culture to the reaction tank, which provided the initial concentration of E. coli equal to 3.4∙106 CFU/cm3. Water treatment for 30 seconds reduced the number of microorganisms to 5.4∙104 CFU/cm3. After 1 minute of treatment this indicator decreased to 1.7∙102 and after 3 minutes the value of 5.2 CFU/cm3 was recorded in the samples, that is, the treated water had indicators of practically pure water. Experiments have proven the effectiveness of plasma disinfection for liquids with high concentration of microorganisms.