| Title: | Mercury speciation in highly contaminated soils from chlor-alkali plants using chemical extractions |
| Author(s): | Neculita CM; Zagury GJ; Deschenes L; |
| Address: | "Department of Civil, Geological and Mining Engineering, Ecole Polytechnique de Montreal, P.O. Box 6079, Station Centre-ville, Montreal, QC, Canada H3C 3A7" |
| ISSN/ISBN: | 0047-2425 (Print) 0047-2425 (Linking) |
| Abstract: | "A four-step novel sequential extraction procedure (SEP) was developed to assess Hg fractionation and mobility in three highly contaminated soils from chlor-alkali plants (CAPs). The SEP was validated using a certified reference material (CRM) and pure Hg compounds. Total, volatile, and methyl Hg concentrations were also determined using single extractions. Mercury was separated into four fractions defined as water-soluble (F1), exchangeable (F2) (0.5 M NH4Ac-EDTA and 1 M CaCl2 were tested), organic (F3) (successive extractions with 0.2 M NaOH and CH3COOH 4% [v/v]), and residual (F4) (HNO3 + H2SO4 + HClO4). The soil characterization revealed extremely contaminated (295 +/- 18 to 11 500 +/- 500 mg Hg kg(-1)) coarse-grained sandy soils having an alkaline pH (7.9-9.1), high chloride concentrations (5-35 mg kg(-1)), and very low organic carbon content (0.00-18.2 g kg(-1)). Methyl Hg concentrations were low (0.2-19.3 microg kg(-1)) in all soils. Sequential extractions indicated that the majority of the Hg was associated with the residual fraction (F4). In Soils 1 and 3, however, high percentages (88-98%) of the total Hg were present as volatile Hg. Therefore, in these two soils, a high proportion of volatile Hg was present in the residual fraction. The nonresidual fraction (F1 + F2 + F3) was most abundant in Soil 1 (14-42%), suggesting a higher availability of Hg in this soil. The developed and validated SEP was reproducible and efficient for highly contaminated samples. Recovery ranged between 93 and 98% for the CRM and 70 and 130% for the CAP-contaminated soils" |
| Keywords: | "*Chemical Industry Chemistry Techniques, Analytical Environmental Monitoring Hydrogen-Ion Concentration Mercury/*analysis/*chemistry Soil Pollutants/*analysis;" |
| Notes: | "MedlineNeculita, Carmen-Mihaela Zagury, Gerald J Deschenes, Louise eng Research Support, Non-U.S. Gov't 2005/01/14 J Environ Qual. 2005 Jan-Feb; 34(1):255-62" |
