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Effects of the buffering capacity of the soil on the mobilization of heavy metals. Equilibrium and kinetics.

Villen-Guzman, Maria; Paz Garcia, Juan Manuel LU ; Amaya-Santos, Gema; Rodriguez-Maroto, Jose M; Vereda-Alonso, Carlos and Gomez-Lahoz, Cesar (2015) In Chemosphere 131. p.78-84
Abstract
Understanding the possible pH-buffering processes is of maximum importance for risk assessment and remediation feasibility studies of heavy-metal contaminated soils. This paper presents the results about the effect of the buffering capacity of a polluted soil, rich in carbonates, on the pH and on the leaching evolution of its main contaminant (lead) when a weak acid (acetic acid) or a strong one (nitric acid) are slowly added. In both cases, the behavior of lead dissolution could be predicted using available (scientifically verified freeware) models assuming equilibrium between the solid and the aqueous phase. However, the experimental results indicate that the dissolution of calcium and magnesium carbonates is kinetically controlled.... (More)
Understanding the possible pH-buffering processes is of maximum importance for risk assessment and remediation feasibility studies of heavy-metal contaminated soils. This paper presents the results about the effect of the buffering capacity of a polluted soil, rich in carbonates, on the pH and on the leaching evolution of its main contaminant (lead) when a weak acid (acetic acid) or a strong one (nitric acid) are slowly added. In both cases, the behavior of lead dissolution could be predicted using available (scientifically verified freeware) models assuming equilibrium between the solid and the aqueous phase. However, the experimental results indicate that the dissolution of calcium and magnesium carbonates is kinetically controlled. These kinetic limitations affect the overall behavior, and should be considered to understand also the response of the metals under local equilibrium. The well-known BCR sequential extraction procedure was used before- and after-treatment, to fractionate the lead concentration in the soil according to its mobility. The BCR results were also in agreement with the predictions of the equilibrium model. This agreement allows new insights about the information that could be derived from the BCR fractionation analysis. (Less)
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author
organization
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type
Contribution to journal
publication status
published
subject
in
Chemosphere
volume
131
pages
78 - 84
publisher
Elsevier
external identifiers
  • pmid:25781866
  • wos:000354584600010
  • scopus:84928724675
ISSN
1879-1298
DOI
10.1016/j.chemosphere.2015.02.034
language
English
LU publication?
yes
id
9f3a4e60-97a7-49ea-8d6d-a1e6cce4c310 (old id 5258355)
date added to LUP
2015-04-15 17:08:41
date last changed
2017-09-03 03:24:56
@article{9f3a4e60-97a7-49ea-8d6d-a1e6cce4c310,
  abstract     = {Understanding the possible pH-buffering processes is of maximum importance for risk assessment and remediation feasibility studies of heavy-metal contaminated soils. This paper presents the results about the effect of the buffering capacity of a polluted soil, rich in carbonates, on the pH and on the leaching evolution of its main contaminant (lead) when a weak acid (acetic acid) or a strong one (nitric acid) are slowly added. In both cases, the behavior of lead dissolution could be predicted using available (scientifically verified freeware) models assuming equilibrium between the solid and the aqueous phase. However, the experimental results indicate that the dissolution of calcium and magnesium carbonates is kinetically controlled. These kinetic limitations affect the overall behavior, and should be considered to understand also the response of the metals under local equilibrium. The well-known BCR sequential extraction procedure was used before- and after-treatment, to fractionate the lead concentration in the soil according to its mobility. The BCR results were also in agreement with the predictions of the equilibrium model. This agreement allows new insights about the information that could be derived from the BCR fractionation analysis.},
  author       = {Villen-Guzman, Maria and Paz Garcia, Juan Manuel and Amaya-Santos, Gema and Rodriguez-Maroto, Jose M and Vereda-Alonso, Carlos and Gomez-Lahoz, Cesar},
  issn         = {1879-1298},
  language     = {eng},
  pages        = {78--84},
  publisher    = {Elsevier},
  series       = {Chemosphere},
  title        = {Effects of the buffering capacity of the soil on the mobilization of heavy metals. Equilibrium and kinetics.},
  url          = {http://dx.doi.org/10.1016/j.chemosphere.2015.02.034},
  volume       = {131},
  year         = {2015},
}