Potentially toxic elements in soils and plants on a reclaimed coal-waste dump in southern Poland : preliminary study

Abstract

The phase composition and concentrations of six potentially toxic elements (Zn, Pb, Mn, Cu, Ni, and Cd) in topsoil and plants were studied. The samples were taken from the waste dump in Katowice in the Upper Silesian Coal Basin. Mineral matter was identified by XRD and SEM. Mineral composition of studied topsoils depends on material composition used to forming the surface layer on the dump. There aluminosilicates (chlorite, muscovite, clays minerals), quartz, Fe and Ca sulphates and Fe oxides dominate. On plants shoots there were identified dolomites, Fe oxides, Ca sulphates, Na and K chlorides and rarely Au-Cu alloys beside quartz and aluminosilicates. By using AAS and ICP-OES contents of heavy metals in soils and plants were determined. Scanning electron microscope allowed to define the chemical composition in soils and plants and XRD to identify mineral contents. In this work measurement of pH and total organic carbon content were carried out. Results indicate that topsoil is highly enriched in heavy metals, especially in zinc, and it is positive correlated with contents of metals in plants growing on such contaminated area. In soils Zn content was in the range from 120 to 3550 mg kg-1, Pb from 31 to 905 mg kg-1, Ni from 3 to 78 mg kg-1 and Cd from1 to 11 mg kg-1. For plants it was respectively Zn to 284 mg kg-1, Pb to 59 mg kg-1, Ni to 4 mg kg-1 and Cd to 1 mg kg-1. The results indicate that application of coal wastes as reclamation material is not advised due to environmental issues.