ORIGINAL PAPER Arsenic ashy soils in Central Slovakia and their chemical and microbiological properties Slavomı ´r C ˇ ernˇ ansky´ 1 • Katarı ´na Pet’kova´ 2 • Zuzana Feketeova´ 3 • L’ubomı ´r Jurkovicˇ 2 • Alexandra S ˇ imonovicˇova´ 3 • Toma´sˇ Farago´ 2 • Toma´sˇ Mackul’ak 4 Received: 2 November 2016 / Accepted: 1 February 2017 / Published online: 9 February 2017 Ó Springer-Verlag Wien 2017 Abstract The aim of the study was to characterize chemical and microbiological properties of soil substrates and fly ash contaminated with arsenic below the active impoundment on six different sites in Zemianske Kosto- l’any area. The substrate of the impoundment and soils around this site are seriously contaminated with arsenic (93–634 lg/g soil) and mercury (0.29–1.67 lg/g soil) exceeding the indication limits for sanitation. Most of the samples give alkaline pH values and low carbon content, which was increased with increasing humidity. This is closely related with the abundance of microorganisms— non-sporulating anaerobic bacteria dominated in the sam- ples. The growth of r-strategists (80–90%) was recorded especially in the ash samples and in the samples with impurities of ash with elevated contents of arsenic and mercury. Among microscopic fungi dominated Ascomy- cota (75.8%) with Aspergillus niger and Penicillium chrysogenum var. chrysogenum which belong to the most tolerant species in this environment. The values of meta- bolic quotient for CO 2 (qCO 2 ) indicate that microorganisms are capable to utilize low sources of organic carbon in such damaged soils. However, low values of the substrate availability index indicate reduced potential of microbiota to degrade organic compounds. Graphical abstract Keywords Soil chemistry Á Fly ash Á Toxic metalloid Á Bacteria Á Fungi Á Microbial biomass Introduction Many inorganic and organic compounds of toxic metals, such as arsenic and mercury, are naturally occurred in the environment. However, human activities often introduce high amounts of various metals and metalloids into soils, water, sediments, and biological systems. It is not only industrial processes and agriculture, which represent sig- nificant sources of metal(loid) contamination in the environment but also mining activities and old mining burdens are responsible for releasing arsenic, mercury, and other toxic elements into the environment. Fly ash, a coal combustion by-product belongs to such sources of arsenic and mercury contamination, which comes primarily from coal-fired electricity generating power plants. It is com- posed mainly of non-combustible inorganic material but also contains some carbon that is a leftover from partially burned coal [1]. The disposal of the residues after burning & Slavomı ´r C ˇ ernˇansky´ cernanskys@fns.uniba.sk 1 Department of Environmental Ecology, Comenius University in Bratislava, Bratislava, Slovakia 2 Department of Geochemistry, Comenius University in Bratislava, Bratislava, Slovakia 3 Department of Soil Science, Comenius University in Bratislava, Bratislava, Slovakia 4 Department of Environmental Engineering, Faculty of Chemical and Food Technology, Slovak University of Technology, Radlinske´ho 9, 812 37 Bratislava, Slovakia 123 Monatsh Chem (2017) 148:593–600 DOI 10.1007/s00706-017-1928-6