The experiment was based on filtration of the highly aggressive water through the melaphyre bed. The quartz bed was non-reactive reference material. The aim of this work was to determine the ability of the melaphyre to remove aggressive CO2 during the chemical reaction. It was noted that a decrease of acidity of the filtrate in comparison to the feed and an increase of its alkalinity and pH. It was calculated that until the moment of exhaustion of the de-acidifying properties of the melaphyre, maximum amount of bound CO2 added to the water was 29.7 g CO2/L of the bed, and maximum amount of the aggressive CO2 removed from the water was 33.3 g CO2/L of the bed. Regarding very high content of the aggressive CO2 (116 mg/L average) in the feed only 28.76% of this component was subject to transformation into bound and affiliated CO2 in the filtrate. For the melaphyre bed the CO2 loss from the experiment system following from desorption was 7.80% of the total load of CO2 added with the feed. On the quartz bed the loss was slightly lower 4.56%.