ACIDIC COMPONENTS OF NATURAL AND WASTE ACIDIC WATERS - NEUTRALIZATION REFINEMENT BY USE OF CALCITE

The term ''total water acidity'' is introduced involving the result of all processes proceeding with the H+ ion release. MIF 31 thermodynamic programs allowing to account the H+ balance in the process of acidic water neutralisation by calcite were applied. It is revealed that the equilibrium in a closed system is attained at pH = 5,3-6,3, the dominant processes determining the acidity being the Fe+3 hydrolise, siderite and malachite deposition and the changes of free H+ concentration. The neutralisation of acidic waters in an open system the pH equilibrium values were found in the interval of 7,4-8,1; main acidity components are concerned as Fe+3 hydrolise and Fe(OH)3 deposition. In the process of acidic water neutralisation by calcite the volume of new formed solid phase, predominantly gypsum is more than 2-fold in relation to the volume of dissolved calcite. This phenomenon is resulted in the colmatage of rocks and the decrease of their water conductivity.