We found a match
Your institution may have rights to this item. Sign in to continue.
- Title
Sorption and desorption of mercury(II) in saline and alkaline soils of Bahía Blanca, Argentina.
- Authors
Lafont, Daniela; Soulages, Olga; Acebal, Silvia; Bonorino, A.
- Abstract
The objective of this work was to study sorption-desorption and/or precipitation-dissolution processes of Hg(II) compounds considering an eventual contact of soils with Hg-bearing wastes. In addition, this study contributes new data about Hg(II) chemistry in alkaline systems. Saline and alkaline soils with low organic matter (<1 %) and high clay content (60-70 %) were obtained near a chlor-alkali plant. Batch techniques were used to perform the experiments using 0.1 M NaNO solutions. Total Hg(II) concentrations ranged from 6.2 × 10 to 6.3 × 10 M. Sorption of Hg(II) was evaluated at two concentration ranges: (a) 6.2 × 10 to 1.1 × 10 M, and (b) 6.4 × 10 to 6.3 × 10 M. At low Hg(II) concentrations, adsorption occurred with a maximum sorption capacity ranging from 4 to 5 mmol/kg. At high Hg(II) concentrations, sorption-precipitation reactions occurred and maximum sorption capacity ranged from 17 to 31 mmol/kg. The distribution of Hg(II) hydrolysis products showed that Hg(OH) was the predominant species under soil conditions. According to sorption experiments, X-ray diffraction and chemical speciation modelling, the presence of Hg(OH) in the interlayer of the interstratified clay minerals can be proposed. Hg(OH) was partially desorbed by repeated equilibrations in 0.1 M NaNO solution. Desorption ranged from 0.1 to 0.9 mmol/kg for soils treated with 5.8 × 10 M Hg(II), whereas 2.1-3.8 mmol/kg was desorbed from soils treated with 6.3 × 10 M Hg(II). Formation of soluble Hg(II) complexes was limited by low organic matter content, whereas neutral Hg(OH) was retained by adsorption on clay mineral surfaces.
- Subjects
MERCURY; SOIL salinity; SODIC soils; HUMUS; CLAY soils; SORPTION techniques; CLAY minerals
- Publication
Environmental Earth Sciences, 2013, Vol 70, Issue 3, p1379
- ISSN
1866-6280
- Publication type
Article
- DOI
10.1007/s12665-013-2221-6