Study of the chemical properties of gravitation dust sediments

The chemical properties of the gravitation dust sediment particles depend on their source. Two samples of the gravitation dust sediment have been investigated. The first sample, collected in locality Košice – Vel’ká Ida, near by U.S. Steel Ltd. (a metallurgy plant), represents the metallurgy industry pollutants. The second sample, collected in Košice city, represents the urban dust. Dust sediments particles create a non-homogeneous system. For this reason, the particles size distribution has been studied. On the base of the obtained experimental results one sample was divided into two approximately same mass fractions. The mineralogical composition of the dust particles matrix was determined by DTA, XRD, and SEM-EDS analyses. The total content of the chosen trace risk elements was defined by various AAS methods. The physical–chemical forms of elements in the dust sediment are characterised by different mobility and biotoxicity. The single-step extraction was used for the isolation of various element forms. 1 mol · dm⁻³ NH₄NO₃, 0.05 mol · dm⁻³ EDTA, and 2 mol · dm⁻³ HNO₃ were used as extraction reagents. The content of the elements in extracts was determined by the FAAS method.