The impact of saline mine water on fate of mineral elements and organic matter: The case study of the Upper Silesian Coal Basin

The work presented here provides a complex environmental impact of sediments in vicinity to the area of the former Lazy coal mine site in the Upper Silesian Coal Basin (Czech Republic). The main aim of this work has been to determine the degree of contamination, to describe the organic matter, and to carry out sorption isotherms to see the size and distribution of pores in the monitored sediments that are the crucial parameters to assumption of removal mechanisms of elements carried in mine water. The results show that the greatest enrichment of Mn, Sr, Ba, and was in sediments of the first tens of meters from the mine water discharge sediments. Ba and Sr were precipitated as mineral barite and thus formed a dominant insoluble component in the river sediments, which were further carried by water flow towards the water reservoirs. Predominant amounts of fossil material and smaller quantities of carbonized and recent organic matter were altered by weathering and erosion processes. The coal materials have a relatively beneficial sorption capacity, which increases with the carbon content. The overburden waste should be considered for use in removing heavy metals in-situ.