Possibility of using a mixture of calcium salts to decrease sulphate concentration and total mineralisation of Surface and mine waters

Natural limestone may be an option for removing sulphates from water. Such waters, which contain high concentrations of sulphate ions, are surface and mine waters. In this work, the removal of sulphate from model solutions (pH 6–8) by their sorption and chemical binding with calcium salts was studied. For experimental studies, natural limestone was taken, which was crushed to 1–10 μm. Such limestone was modified with acetic acid. A mixture of grinding limestone with the obtained calcium acetate was used for research. Experiments conducted in static conditions showed a decrease in sulphate concentration from 1.2 to 0.38 mg·dm–3 for a duration of 3 days and adding CaСО3:Са(СН3СОО)2 in a ratio of 1 : 1. The analysis of various scientific studies allowed us to assume that when such a mixture of calcium salts is used to reduce sulphate ions in natural surface waters, the formed acetate ion will undergo biological degradation. Thus, it is possible to achieve a reduction in the total mineralisation of surface waters.