APPLICATION OF VARIOUS METHODS FOR SULPHATES REMOVAL UNDER ACIDIC CONDITIONS.

The occurrence of acid mine drainage is usually associated with mining activities. Acid mine drainage usually due to low pH (3-4) contains high concentrations of sulphates and heavy metals, and because of water pollution and devastation of the country can cause serious environmental problems. Depending on the hydrological characteristics of the region, it may affect a much larger area and can cause the deterioration of the quality parameters of surface and groundwater and the consequent threat to human health. According to Directive 2000/60/EC of the European Parliament it is necessary to ensure adequate water quality and protection of all water sources. In Slovak Republic, as the country with long mining traditions, now exist a few localities with existing acid mine drainage generation conditions (either in form of direct outflow from mine or leachate from tailing ponds). Low pH of these waters is limiting for many various treatment technologies and must be taken into consideration in the research of potential methods for acid mine drainage treatment. The presented paper deals with the utilisation of different substances for sulphates removal from model acidic solutions that imitate the conditions of acid mine drainage. Results of sorption experiments with surface modified silica and also precipitation using barium chloride and Portland cement are presented. [ABSTRACT FROM AUTHOR]