Effects of an integrated carbide slag-mushroom dreg-calcium superphosphate amendment on the stabilization process of Pb, Cu, Zn and Cd in contaminated soils

Abstract

In the present study, the integrated use of organic and inorganic amendments (CS-MD-CSP) including carbide slag (CS), calcium superphosphate (CSP) and mushroom dreg (MD) are employed for the stabilization of heavy metals in contaminated soils. A response surface methodology combined with immobilization efficiency was employed to evaluate and optimize the proportion of the integration amendments on the stabilization process. The results predicted by a Box-Behnken design indicated that the maximum immobilization efficiencies of soil Pb, Cu, Zn and Cd could be achieve up to 99.88, 96.11, 99.78 and 87.88%, respectively, when the dosage of CS, CSP and MD were set as 4, 1 and 6%, respectively. European Community Bureau of Reference (BCR) speciation analysis indicated that the acid-soluble proportion of Pb, Cu, Zn and Cd in the soils decreased by 72.68, 37.03, 9.36 and 12.94%, respectively. Thus, this CS-MD-CSP integration amendment could potentially be used for the remediation of Pb, Cu, Zn and Cd in contaminated soils.