Application of Emulsified Liquid Membrane Technology to Remediate Heavy Metals in Soil and Sediments

摘要

Heavy metal contamination of soils, sediments and groundwater presentsan ongoing source of hazardous and persistent environmental pollution. How best toremediate these contaminants is the stimulus of continuing research efforts. Methodsinclude containment, ex situ and in situ techniques. A successful in situ method utilizinga combination of emulsified liquid membranes and zero-valent metal and bimetals hasdemonstrated impressive heavy metal reduction in 100 ppm solutions of Cd, Cu, Ni, Pb,Cr and U. Vial studies with Pb spiked sediment have shown repeatable 60% removal ofPb in spiked soils and sediments after seven days of treatment. A persistent patternemerged at ten days whereupon remediation levels began to drop. The current study wasestablished to determine the reason for the decline at ten days and beyond. Questionsaddressed: Does the formation of an oxide layer diminish the remediation capacity of theiron/magnesium system? Does the emulsion reach a maximum capacity to bond with thecontaminant? Were the soil components or the soil structure interfering with the accessto the contaminant?