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Sulphates are present in effluents of many industries, especially hydrometallurgy due to the widespread use of sulfuric acid in many processes and they are also the main anions in acid mine drainages that are product of sulphide oxidation. Sulphates are the contaminant with negative impact on water environment, therefore it should be removed from wastewater using an adequate process of treatment. Sulphates containing wastewaters or mine drainages are usually treated by a combination of operations including acidity neutralization, lime (or limestone) precipitation, reverse osmosis, electrodialysis and adsorption. The selection of the treatment process of such effluents is a function of many factors such as chemical availability, local regulations and process economics. Recent research has shown that biosorption by low cost biomass can also be an effective alternative. The paper deals with the sulphate removal from model solutions (initial concentration of sulphate ions 15 and 75 mg.L-1, respectively) by the natural biosorbents - wood sawdusts. Hornbeam sawdust had over 99 % efficiency for sulphate removal from model solution with initial concentration 15 mg.L-1. [ABSTRACT FROM AUTHOR]

The contamination of aquatic and terrestrial ecosystems with heavy metals and other mining chemicals have been major environmental problems in many mining areas of the world. Industrial wastes, geochemical structure and metals mining create a potential source of heavy metal pollution in the aquatic environment especially in sediment. Water reservoir Ruzin located in east Slovakia is one of the most contaminated sites by heavy metals originating from mining activity. Water reservoir Ruzin I. is situated in territory, which is well-known by its mining and metallurgical history for several centuries, such as ore deposit Smolnik. Surface water from this area is contaminated by acid mine drainage (AMD) outflowed from abandoned sulphide mine Smolnik. AMD with low value of the pH (about 3-4) is a result of chemical oxidation of sulphides and other chemical processes in mine. The pH increasing due to the mixture AMD with surface water is followed by metal precipitation and its sedimentation in water environment. Contaminated sediment is transported by erosion processes into the river Hnilec and then into water reservoir Ruzin. The data in this work were undergo several experimental procedures including statistical analyses, normalization and estimating anthropogenic impact factors to establish the concentration and identify the status of each heavy metal under investigation. The aim of this study was to evaluate the chemical quality of the sediment influenced by the mining activities from Smolnik creek through the Hnilec river until to water reservoir Ruzin I. by calculation of the enrichment factor, pollution load index and geoaccumulation index. [ABSTRACT FROM AUTHOR]

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]

Aquatic sediment contaminated with heavy metals is still an unsolved problem in Europe. The problem is serious also in the Slovak water reservoirs. Water reservoir Ruzin located in east Slovakia (situated on the Hornad river) is one of the most contaminated sites by heavy metals coming from abandoned metallurgical mines produced acid mine drainage (AMD). These acidic waters, which frequently contain high concentrations of heavy metals, often have adverse effect on the quality and ecology of waters receiving the effluent. Bottom sediments in this reservoir are contaminated above all by heavy metals, which are alluvial into the reservoir from localities of former mining activities and thus they represent ecological load mainly at the inputs into reservoir. The large share of pollution is coming from the Hnilec catchment where is situated the abandoned mine Smolnik. The aim of this paper is assess the quality of sediments along its course from the source (Smolnik creek - Hnilec creek) to the mouth (reservoir Ruzin) based on the requirements of Slovak and EÚ legislation. Use of these tools can provide essential characterizations of key watershed sources, sensitive receptors, natural variation, and both natural and anthropogenic stressors. Only with these multiple tools and an understanding of their interactions can reliable determinations of sediment pollution and longterm consequences be made. Then cost-effective, environmentally protective management decisions can be made about the type, extent, and need for sediment remediation. [ABSTRACT FROM AUTHOR]

Water quality monitoring has one of the highest priorities in environmental protection policy. The main objectives are to control and minimise the incidence of pollutant-oriented problems, and to provide water of appropriate quality to serve various purposes such as drinking water supply, irrigation water, etc. Pollution of the natural environment by heavy metals is a universal problem because these metals are indestructible and most of them have toxic effects on living organisms, when permissible concentration levels are exceeded. The degree of contamination in the the Smolnik creek, for the metals Ca, Mg, Fe, Mn, Al, Cu, Zn, As, Cd and Pb, has been evaluated using Enrichment factor (EF) and Pollution load index (PLI). Effect of heavy metals from mining activities in the Smolnik creek water evaluated using enrichment factor, present all indicators at deficiency to minimal enrichment to moderate enrichment. The content of sulphate in water show an extremely high enrichment in the water flow, it is represent as a high contamination of the water flow in Smolnik creek. Very high levels of pollution load index PLI (> 1) for both sampling sites are extremely high contamination with heavy metals. Declining value of PLI is due to dilution and spreading of heavy metals with distance from the source of contamination. [ABSTRACT FROM AUTHOR]

Manufacturing process, primarily mining activities, often result in the production of effluents containing high amounts of sulphate and heavy metals. These effluence are known as acid mine drainage (AMD) and is produced when sulphide - bearing material is exposed to oxygen and water. AMD usually due to low pH (2-5) contains high concentrations of inorganic pollutants (such as sulphates and heavy metals), which impact surface and groundwater. Consequently AMD prior to being released into the environment must be treated to meet government standards for the amount of inorganic pollutants contained in the water. Low pH is limiting for many various treatment technologies, including sorption. The paper deals with the study of two different methods (sorption and precipitation connected with oxidation) for heavy metals and sulphates removal from model acidic solutions [ABSTRACT FROM AUTHOR]

Aquatic sediments contaminated with heavy metals are still an unsolved problem in numerous industry sites in Europe. Water reservoir Ruzin located in east Slovakia is one of the most contaminated sites by heavy metals coming from mining and metallurgical industry. Mining activities are known to release significant amounts of toxic metals into the surrounding environment. The Ruzin water reservoir is situated in the Hornad River. The filling process of the reservoir began in 1969. During 40 years its volume was diminished by 10 million cubic meters. Bottom sediments are contaminated by heavy metals, namely Hg, Cu, Zn, Cd, Pb, Cr, Co, Sb and As which originate from the former mining activities e.g. locality Smolnik and represent the ecological loads mainly at the inputs into reservoir. This study presents the characterisation of the contaminated sediments from the water reservoir Ruzin by using of qualitative XRF analysis and FTIR method [ABSTRACT FROM AUTHOR]