Effects of sewage sludge on the accumulation of heavy metals in soil and in mixtures of lawn grasses

The study was conducted on three specially prepared test areas along main streets of Bialystok. The experimental plots were sown with two lawn grass mixtures: Eko and Roadside, and three doses of sewage sludge 0.0 (control), 7.5 kg/m2 and 15.0 kg/m2 were used. The calculated bioconcentration factor made possible to determine the mobility of the various metals from the soil solution to the aerial parts of plants. The obtained results showed that the plants absorbed Cd, Zn, Cu easier than Pb and Ni suggesting a high mobility, in particular of Cd, Zn, Cu, and reflects the easiness extraction of those metals by plants. Significant correlations between concentrations of metals in soil and grass were observed, nickel in soil was significantly correlated with Cd, Zn and Cu in plants, while the Zn content in soil with the level of Cu in plants.