Treatment of clay soil contaminated with lead by in-situ immobilization process using animal bones

In this work, the application of bone wastes –Cow Bone, Pig Bone, and Horse Bone for the treatment of Lead (Pb) in Clay Soil by in-situ immobilization process, was investigated. The bone wastes were carbonized at a temperature of 700 OC for five hours. The Cow Bone Ash (CBA), Pig Bone Ash (PBA), and Horse Bone Ash (HBA) obtained were characterized with X-Ray Fluorescence (XRF). The physicochemical analysis of the soil sample was also performed. Batch experiments were done to investigate the effects of amendment dosage, time, and pH on immobilization efficiency. The physicochemical characterization of the amendments showed that they contain principally calcium phosphate. The XRF revealed that CBA contains 49.25 % CaO and 42.406 % P2O5, PBA contains 46.6 % CaO and 40.488 % P2O5 and HBA contains 45.664 % CaO and 33.857 % P2O5. The batch immobilization experiment revealed that CBA performed better than other sorbents in the removal of Pb. The removal efficiency is in the order CBA > PBA > HBA. The maximum removal of Pb in 100 g of soil was 71.2 %. This investigation has shown that animal bones can successfully remediate lead by immobilization process in a Pb contaminated Clay soil.