Leaching characteristic of solidification/ stabilization for Cu2+ contaminated soils with carbide slag and metakaolin

Abstract:

The geopolymer, consists of carbide slag (CS) and metakaolin (MK), was used to solidify and stabilize the Cu₂₊ contaminated soils. A series of toxic characteristic leaching procedure (TCLP) tests were conducted on the solidified soils and then the optimal contents of CS and MK were selected for this geopolymer. The results obtained from laboratory experiments show that the pH of leaching solution increases and the Cu₂₊ concentration decreases with the increases in CS content, while the Cu₂₊concentration does not continue to reduce when the CS content is more than 9%. As MK content increases, the pH of leaching solution decreases slightly, but the Cu₂₊concentration firstly decreases and then increases. Based on the results, the optimal contents of CS and MK were selected for this geopolymer to be 10% and 5%, respectively.

Key words:Cu₂₊ contaminated soils; Stabilization/ solidification; Geopolymer; TCLP test