title: Evaluating the applicability of regulatory leaching tests for assessing the hazards of Pb-contaminated soils.
abstract: Soil contamination is a major environmental problem due to the ecological threat it poses. In this work, electron probe microanalysis (EPMA), X-ray diffraction (XRD), and leaching studies were employed to explain the different leaching behaviors of non-stabilized and stabilized soils. The applicability of the leaching fluids used in the toxicity characteristic leaching procedure (TCLP) and Australian Standards, AS 4439.1-1997 for assessing the hazards of contaminated soils was investigated as was the leaching of lead from soil stabilized by cement and buffered phosphate techniques. The results showed Pb speciation in the soil highly influenced metal leaching. The synthetic leaching fluids were unable to provide a reliable estimation of Pb concentration in the municipal landfill leachate (ML) due to the absence of organic ligands capable of forming stable complexes with the lead. Water provided the closest representation of lead leaching from the non-stabilized and phosphate stabilized soils while sodium tetraborate buffer was found to be suitable for cement-stabilized soil in a non-putrescible landfill leachate system. A comparison of stabilization methods revealed that the buffered phosphate technique was more suitable for stabilizing the lead in the soil relative to cement stabilization.
authors.affiliation: ARC Centre for Functional Nanomaterials, School of Chemical Engineering and Industrial Chemistry, The University of New South Wales, Sydney, NSW 2052, Australia.
authors.forename: Cheryl E
authors.initials: CE
authors.lastname: Halim
authors.forename: Jason A
authors.initials: JA
authors.lastname: Scott
authors.forename: Rose
authors.initials: R
authors.lastname: Amal
authors.forename: Stephen A
authors.initials: SA
authors.lastname: Short
authors.forename: Donia
authors.initials: D
authors.lastname: Beydoun
authors.forename: Gary
authors.initials: G
authors.lastname: Low
authors.forename: Julie
authors.initials: J
authors.lastname: Cattle
mesh_terms: D004787:Environmental Pollution / Q000517:prevention & control*; D006256:Hazardous Waste; D007854:Lead / Q000032:analysis / Q000737:chemistry*; D012037:Refuse Disposal; D018570:Risk Assessment; D012989:Soil Pollutants / Q000032:analysis*; D012995:Solubility
chemical_list: D006256:Hazardous Waste; D012989:Soil Pollutants; D007854:Lead