Immobilization of nanoparticles by occlusion into microbial calcite

Skuce, R. L., Tobler, D. J., MacLaren, I. , Lee, M. R. and Phoenix, V. R. (2017) Immobilization of nanoparticles by occlusion into microbial calcite. Chemical Geology, 453, pp. 72-79. (doi: 10.1016/j.chemgeo.2017.02.005)

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Binding of nanoparticles (NPs) to mineral surfaces influences their transport through the environment. The potential, however, for growing minerals to immobilize NPs via occlusion (the process of trapping particles inside the growing mineral) has yet to be explored in environmentally relevant systems. In this study, the ureolytic bacteria Sporosarcina pasteurii was used to induce calcium carbonate precipitation in the presence of organo-metallic manufactured nanoparticles. As calcite crystals grew the nanoparticles in the solution became trapped inside these crystals. Capture of NPs within the calcite via occlusion was verified by transmission electron microscopy of thin foils. Nanoparticles with a negative surface charge were captured with greater efficiency than those with a positive surface charge, resulting from stronger attachment of negative nanoparticles to the positively charged calcite surfaces, which in turn facilitated occlusion. Thermodynamic and kinetic analysis, however, did not reveal a significant difference in kp (calcite precipitation rate constant) or the critical saturation at which precipitation initiates (Scrit), indicating the presence of different charged nanoparticles did not influence calcite precipitation at the concentrations used here. Overall, these findings demonstrate that microbially driven mineral precipitation has potential to immobilize nanoparticles in the environment via occlusion.

Item Type:Articles
Glasgow Author(s) Enlighten ID:Tobler, Dr Dominique and Lee, Professor Martin and MacLaren, Dr Ian and Phoenix, Dr Vernon
Authors: Skuce, R. L., Tobler, D. J., MacLaren, I., Lee, M. R., and Phoenix, V. R.
College/School:College of Science and Engineering > School of Geographical and Earth Sciences
College of Science and Engineering > School of Physics and Astronomy
Journal Name:Chemical Geology
ISSN (Online):1872-6836
Published Online:06 February 2017
Copyright Holders:Copyright © 2017 The Authors
First Published:First published in Chemical Geology 453:72-79
Publisher Policy:Reproduced under a Creative Commons License

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Project CodeAward NoProject NamePrincipal InvestigatorFunder's NameFunder RefLead Dept
474402Biogeochemical Applications in Nuclear Decommissioning and Waste DisposalVernon PhoenixEngineering & Physical Sciences Research Council (EPSRC)EP/G063699/1SCHOOL OF GEOGRAPHICAL & EARTH SCIENCES