Mobility and Bioavailability of Heavy Metals after the Addition of High Levels of Cu on the Technogenically Affected Soils

M. Teoharov, Ts. Simeonova, L. Nenova, E. Atanasova, I. Atanasova

Abstract: Three technogenic soils from the industrial area of the metallurgical plant “Kremikovtsi” and an uncontaminated control soil from the region of the village of Seslavtsi were investigated. The soils are characterized by a neutral to slightly alkaline reaction and elevated levels of heavy metals, Zn, Cu, Mn, Fe and Pb, compared to the control. The soils are additionally contaminated with copper (at levels 500 mg/kg and 1000 mg/kg) in order to approximate the adsorption maxima in Cinnamonic Forest Soil (Chromic Luvisol). The development of rocket plants (Eruca sativa) was studied in a pot experiment. The yield and the heavy metal contents of plants were analyzed. Pseudo-total and bioavailable forms of heavy metals in soils were assessed (ISO 11466; 1M NH4NO3). The yield of the rocket plans was highest in the control unpolluted soil and decreased by 43% after the addition of 1000 mg/kg Cu to the soil. The additional pollution of the Technogenic soils lead to lower yields and significant increase in the concentration of copper in the plants in all of the investigated variants. These two parameters are related by correlation coefficient R = -0.637. In some variants a synergism between the bioavailability of copper and manganese was observed. As regards the iron, lead and zinc, the tendency is the opposite. The proportion of the bioavailable forms of copper from the total is higher in the technogenically affected soils after pollution. The proportion of the bioavailable forms of zinc, manganese, iron and lead from the total is higher in the control soil with lower pH.

Keywords: bioavailability; heavy metals; technogenically affected soils

Date published: 2016-12-05