Determination of heavy metals and radionuclides in the alluvial soil and clay of the river Danube

Abstract

Contaminated an unpure ground is this ground which containes (between of the rest) unallowed quantity of heavy metals: Cr, Mn, Cu, Zn, Cd, Hg, Pb, As and others. The greates danger comes from immediately accepted ions of toxic metals and very dispersed, easily soluble compounds. Metal toxicity is not expressed by their harmful effect on plants only, but on the soil microflora and microfauna. The aim of this study was to find out whether there was the alluvium of the Danube and clay in its immediate vicinity, as the result of NATO aggression during 1999. The alluvium sample collected downstream from the imaginary line indicated deviations from the alluvium taken upstream and the clay sediment, in the near Batajnica airport. In this paper used the next experimental method: determination of contents of dry substances, determination of alcaline-ground's carbonates, determination of contents of microelements by the AAS method, with the intention of examination ground's unpurity, that is the presence of heavy metals, alcaline-ground's carbonates and contents of dry substance. The results showed that there were no changes in the Danube alluvium ana that there was no contamination by heavy metals and radionuclides. The clay sample indicated a somewhat higher content of nickel than maximum allowed soil concentration, however, this was not a result of momentary contamination. This results may be interpreted in two ways: a) by earlier contamination with river alluvium or b) the nature of the sediment itself. .

Kontaminirano ili zagađeno zemljište je ono zemljište koje, između ostalog, sadrži nedozvoljene količine teških metala: Sr, Mn, Cu, Zn, Cd, Hg, Pb, As i dr. Usvajanje teških metala od strane biljaka zavisi od hemijske forme u kojoj se oni nalaze u zemljištu. Najveću opasnost predstavljaju neposredno usvojeni joni i jako dispergovana, lako rastvorna jedinjenja. Toksičnost metala ne ispoljava se štetnim dejstvom samo na biljke, nego i na mikrofloru i mikrofaunu zemljišta. Cilj ovoga rada bio je utvrđivanje eventualne kontaminacije aluvijalnog nanosa reke Dunav u neposrednoj blizini uzimanja uzoraka sedimenta, kao rezultat NATO-bombardovanja (agresije) tokom 1999. Uzorci aluvijalnog nanosa reke Dunav uzimani su uzvodno i nizvodno u odnosu na zamišljenu liniju koja povezuje Dunav sa aerodromom u Batajnici koji je bio intenzivno bombardovan. Uzorak gline uziman je u neposrednoj blizini mesta gde su uzeti uzorci aluvijalnog nanosa. U radu je obavljeno: određivanje sadržaja: suve supstance, zemnoalkalnih karbonata, mikroelemenata metodom atomske apsorpcione spektrofotometrije u cilju utvrđivanja kontaminiranosti zemljišta, tj. prisustva teških metala i suve supstance. Dobijeni rezultati pokazali su da uzorci aluvijalnog nanosa nisu bili kontaminirani. Uzorak gline ima nešto veći sadržaj nikla od maksimalno dozvoljene koncentracije u zemljištu, što, međutim, nije rezultat trenutne kontaminacije. Ovaj rezultat se može tumačiti na dva načina: a) ranijom kontaminacijom rečnim nanosom, ili b) prirodnim fonom samog sedimenta. .