Sewage sludge application effects to first year willows (Salix Viminalis L.) growth and heavy metal bioaccumulation

Abstract

The effects of sewage sludge application on first year willows (Salix viminalis L.) and the accumulation of heavy metals in plants were investigated. Plants were exposed to 1–15 kg m-2 of sewage sludge under field conditions. Willows were grown in the field for 6 months. Sewage sludge application enhanced willows growth. Stem height of willows grown in soil treated with sludge were by 15–31 % higher than those grown in control plots. The biomass of stems and roots were by 26–61 % and 36–62 %, respectively, higher than that of control plants. Sludge application resulted in increased heavy metals concentrations in soil and willows. Metals concentrations were plants tissue and sludge application rate dependent. The highest bioconcentration factor was detected for Cd. Due to uptake of heavy metals by willows, the concentrations of Cu, Zn, Cd in soil (at 20 and 40 cm depth) were significantly reduced after the growing season.