Introduction Results & Discussion At present, disinfection of wells and drinking water pipelines is carried out by treating with chlorine- containing reagents. There are a lot of disadvantages of chlorination methods. Also, using chlorine disinfectants has limited effect on the inner surface of well from the top water level up to the well head, and almost no disinfection of the small layer of water above the pump (fig. 1). Conclusions Figure 2: Biological contamination on the internal surface of a water well Research results were the basis for the development of technology and mobile installation for the disinfection of water wells. Disinfection of water well is carried out in one step. The optimal treatment time is not longer than 30 minutes, which is in 10–15 times lower than using existing methods of disinfection with chlorine-containing reagents. Payback period of this mobil unit is 1.3 year To date, ozone is a powerful disinfectant that can be used to disinfect water wells. Use of ozone will significantly reduce the treatment time and increase the degree of disinfection, reduce the impact on the environment. As a raw material for the production of ozone air can be used, which greatly reduces the cost of the process. Figure 1: Contamination of water well, and identification of surfaces which are less susceptible to treatment using chlorine disinfectants Solubility of ozone in a liquid column The results obtained were: the spatial distribution of dissolved ozone concentration in the water column from the ozone flow, the ozone concentration in the gas mixture, and processing time. Experiments were carried out with a static volume of water and at constant inflow rate The results of ozone dissolubility research with a static volume of water are shown in fig. 3. Experimental conditions: ozone-containing gas flow rate of 700 l/h. Volume of treated water – m 3. a) b) c) а – the concentration of ozone in the gas mixture 35 g/m 3 ; b – the concentration of ozone in the gas mixture 45 g/m 3 ; c – the concentration of ozone in the gas mixture 55 g/m 3 Figure 3: Dissolved Ozone Concentration (mg/l) in a static volume of water at different initial concentration it in the gas mixture Results of the study ozone solubility with constant water flow rate of 12 l/min are shown in fig. 4. a) b) c) а – the concentration of ozone in the gas mixture 15 g/m 3 ; b – the concentration of ozone in the gas mixture 20 g/m 3 ; c – the concentration of ozone in the gas mixture 35 g/m 3 Figure 4: Dissolved ozone concentration (mg/l) in water at a constant flow rate of 12 l/min in height of the liquid column at different initial concentration in the gas mixture Based on the graphs of ozone water saturation as well as the dynamics of its decomposition can be noted that well treatment can be best employed during downtime; with processing times of only up to 30 mins required. However, in each particular case the treatment time will depend on parameters of well water intake and the ozone generator used. Field tests at the water intake station in settlement Yurovtsy near Bialystok (Poland) confirmed the obtained graphic dependences. In order to address problems and shortcomings of currently available methods of disinfection of water wells mentioned above, alternatively, ozone may be used as a disinfectant. According to various experiments presented in the literature, ozone exceeds the performance of all chlorine disinfectants; According to its bactericidal effects, ozone is 3–6 times better than UV radiation and 400–600 times more than chlorine. In the samples selected from the inner surface of the well found biological contamination (fig. 2). Definition of corrosion activity of disinfectants Another important issue to be considered when using ozone as a disinfectant is to compare its corrosive activity to chlorine disinfectants solutions. To determine the corrosive activity, the following reagents were used: calcium hypochlorite, sodium hypochlorite, bleach, a saturated solution of ozone in water. The investigated concentrations of chlorine-containing disinfectants were: 50, 100 and 150 mg/l of active chlorine. To generate the ozone used experimental cascade a turboozonator with concentration of ozone in the gas mixture 2.7 g/m 3 was used. Flow rate of gas mixture was 13.2 l/min. For the corrosion tests plates from carbon steel grades of two different marks St 37-3 and Ct 20 were used. To determine the resistance group of metal relative to disinfectant solutions, calculation of weighting corrosion rate (K m, g/m 2 ∙h) and deep corrosion rate (K g, mm/year) was performed, which characterises the uniform corrosion and corresponds to a decrease in metal thickness due to corrosion. Depth and weight indicators of corrosion in a saturated solution of ozone is 14.4 times less than for steel St20. Among the chlorine disinfectants, the most corrosive are sodium hypochlorite solutions. Deep corrosion rates are up to 9.6 and 4.9 times higher for steel St37-3 and up to 8.8 and 9.8 times higher for steel Ct20 than when calcium hypochlorite bleach solutions are used, respectively. In some experiments, passivation of the metal is observed with increasing concentration of active chlorine in the solution due to the formation of poorly soluble CaCO 3 on the metal surface. The transition of metal in the passive state is accompanied by deceleration of corrosion rate with an increase concentration of the active substance in solution. The weighting and depth indicator for steel St37-3 is significantly lower than for steel Ct20. That is, with increasing carbon content corresponded with observed acceleration of corrosion. This is because the process of corrosion in acidic environments usually controlled by the process of hydrogen depolarization, the rate of which increases with the square areas on the cathode metal surface. Such cathode sections for carbon alloys is cementite, the amount of which is increased in the steel with increasing carbon concentration. For steel grade Ct20 weight and depth corrosion indicators of a saturated solution of ozone exceed levels in chlorine disinfectants solution up to 31.4 and 31.2 times. For steel St37-3, the weight corrosion index of a saturated solution of ozone is almost 2 times higher than the values ​​ for calcium hypochlorite and bleach, and up to 2.5 times lower than the values ​​ for sodium hypochlorite solutions. It should be noted that the time for processing of wells using ozone does not exceed 15–20 min, while the weight rate of corrosion for steel Ct20 is 2.2 g/m 2, and because disinfection using chlorine solutions can last from 8 to 24 hours and the weight corrosion rate will be equal to g/m 2 for bleach solution with a concentration of active chlorine 100 mg/l. Thus, it can be concluded that in one step disinfection plant materials are subjected to a lesser degree of corrosion when using a saturated solution of ozone, rather than using chlorine disinfectants. Comparative analysis of the corrosive activity of disinfectants shows that the use of dissolved ozone in addition to achieving a more effective disinfection result will cause less corrosion of wells constructed from steel materials. New method of disinfecting water well V.I. Ramanouski*. A.D. Hurynovich** * Department of Industrial Ecology, Belarusian State Technological University, Sverdlova str., 13a, Minsk, , Belarus ( ** Department of engineering systems in environment protection, Belostok Technical University, Vejska Str., 45, Bialystok, Poland