The presence of managanese in drinking water is undesirable due to harmful effects on people’s health upon larger accumulation in the body. In the thesis the solutions of managanese have been treated with ozone and hydrogen peroxide. By oxidating manganese, its concentration in the water has been lowered to the boundary level of approximately 0.05 mg/L. With the ozonation of MnCl2 and MnSO4 solutions during a time period of 150 minutes, the differences in the velocity of reducing the concentration of manganese of the aforementioned solutions have been determined in the water from waterworks and demineralized water. The efficiency of removal has been better in the MnCl2 and MnSO4 solutions with the tap water. The reason for better removal in the water from waterworks has been the buffer capacity of water due to presence of dissolved carbonates on account of which the solution of water from waterworks retained constant pH value, while in the solutions with demineralized water pH value dropped due to creation of hydrogen ions during the reaction of manganese and ozone. Due to creation of hydrogen ions during ozonation, the electrical conductivity has increased. The adding of hydrogen peroxide in the solution of manganese with the initial concentration of 2 mg/L did not result in its reduction after the time period of 60 minutes.