Leaching behavior of copper and chromium in the mortar containing artificial fine aggregate prepared by contaminated soil

Abstract

The feasibility of recycling contaminated soil by preparing artificial fine aggregate (AFA) and applying in artificial fine aggregate mortars (AFAM) was investigated systematically. Properties and heavy metal immobilization status of AFA, compressive strength and heavy metal leaching behavior of AFAM were tested. Results showed that Cu reduced the melting and crystallization temperatures of AFA, whereas Cr improved that. Heavy metal addition had a negative impact on the compressive strength of AFAM, but the toxicity characteristic leaching procedure (TCLP) test indicated that the AFAM system was is suitable for solidification of heavy metals. Moreover, it was observed that Cu leaching almost disappeared in the initial periods, while it tended to dissolve in the terminal periods. The leaching mechanism of AFAM with Cr at the initial periods conformed to Fick's law of diffusion, and it tended to deplete in the terminal periods. These results are practically instructive the recycling of heavy metal contaminated solid waste in the field of construction materials.