Experimental study of the redistribution of heavy metals contaminants in coarse-grained soils by unidirectional freezing

To remediate polluted soils, unidirectional freezing experiments were conducted on porous packs made of glass beads or coarse sand grains, and saturated by dilute clayey suspensions charged with a heavy metal, zinc or lead. In this paper, we made evident that the low-rate propagation of a unidirectional freezing front leads to the rejection of both soluble and nonsoluble chemical forms of the metallic pollutants in the porous media. Moreover, we outlined the influence of several parameters on the efficiency of this remediation technique: pH of the suspension, nature of the porous material, nature of the metallic pollutant. (C) 2003 Elsevier B.V. All rights reserved.