Open Access Highly Accessed Research article

Partitioning of silver and chemical speciation of free Ag in soils amended with nanoparticles

Rachel Benoit, Kevin J Wilkinson and Sébastien Sauvé*

Author Affiliations

Department of Chemistry, University of Montreal, Succ. Centre-Ville, P.O. Box 6128, Montreal, QC, H3C 3J7, Canada

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Chemistry Central Journal 2013, 7:75  doi:10.1186/1752-153X-7-75

Published: 25 April 2013

Abstract

Background

Knowledge about silver nanoparticles in soils is limited even if soils are a critical pathway for their environmental fate. In this paper, speciation results have been acquired using a silver ion selective electrode in three different soils.

Results

Soil organic matter and pH were the most important soil properties controlling the occurrence of silver ions in soils. In acidic soils, more free silver ions are available while in the presence of organic matter, ions were tightly bound in complexes. The evolution of the chemical speciation of the silver nanoparticles in soils was followed over six months.

Conclusion

During the first few hours, there appeared to be a strong sorption of the silver with soil ligands, whereas over time, silver ions were released, the final concentration being approximately 10 times higher than at the beginning. Ag release was associated with either the oxidation of the nanoparticles or a dissociation of adsorbed silver from the soil surfaces.

Keywords:
Chemical speciation; Complexation; Environmental fate; Ion selective electrode; Nanoparticles; Nanosilver; Contaminated soils

Graphical abstract