Fractionation of Heavy Metals in the Sewage Sludge Applied Soil

An incubation experiment was conducted to investigate the effects of sludge application to soil on heavy metal bioavailability, metal mobility and metal fractionation.A thermal stabilized sewage sludge was applied to the uncontaminated calcareous red Mediterranean soil, and after 6 months incubation period, soil heavy metals (Zn, Cu, Ni, Pb and Cd) were analyzed.Sludge application has significantly increased the DTPA extractable metals and all the metals in the water-soluble and exchangeable fractions.Sludge application significantly increased the mobility factor of all metals.Zn, Pb and Ni were the most increased metals in the soil by sewage sludge application.