PIERWIASTKI ŚLADOWE W OSADACH RZEKI BRDY W BYDGOSZCZY

Abstract

TRACE ELEMENTS IN SEDIMENTS OF THE BRDA RIVER IN BYDGOSZCZ

Abstract. In the city of Bydgoszcz, sediment samples were token from 22 embankment cones in the Brda River, formed near the outlets of sewers through which waste water was discharged into the river. One averaged sample, which was obtained by combining 4 to 9 full-thickness cores taken at different locations of the cone, was collected front each cone. The samples were analysed for As, Ba, Cr, Pb, Co, Cu, Ni, Sn and Zn contents by the ICP-OES method, and for Hg content using the AAS method with pre-concentration on a gold amalgamate trap. The maximum levels of individual elements were as follows: Hg - 2.72 mg/kg, Cd - 6.9 mg/kg Cr - 255 mg/kg, Sn - 19 mg/kg, Zn - 592 mg/kg, Cu - 231 mg/kg, Ni - 74 mg/kg, Pb - 301 mg/kg, and Ba - 233 mg/kg. The concentrations exceeding permissible limits of Hg, Pb, Cr, Cu, according to the Decree of the Minister of the Environment (Rozporządzenie, 2002) for dragged sediments, were found in 11 embankment cones. It was estimated that the embankment cones set up at the months of the sewers have accumulated about 8.6 thousand m³ of sediments, of which about 4.5 thousand m³ of sediments were uncontaminated and could be relocated within the body of water, and about 4.1 thousand m³ of sediments were contaminated.