Strontium sorption and precipitation reactions at Shewenella and hydrous ferric oxide (HFO) surfaces

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Authors:Warren, Lesley A.; Ferris, F. Grant; Roden, Eric E.
Author Affiliations:Primary:
University of Toronto, Department of Geology, Toronto, ON, Canada
Volume Title:Geological Society of America, 1997 annual meeting
Source:Abstracts with Programs - Geological Society of America, 29(6), p.128; Geological Society of America, 1997 annual meeting, Salt Lake City, UT, Oct. 20-23, 1997. Publisher: Geological Society of America (GSA), Boulder, CO, United States. ISSN: 0016-7592
Publication Date:1997
Note:In English
Summary:Radionuclide contamination, e.g. Sr, of groundwater environments requires the development of effective remediation strategies. Bioremediation techniques involving bacteria appear very promising as they provide a potentially low cost effective treatment for removal of metal contaminants from aqueous environments. The ability of microbes to sorb metals effectively from solution as well as precipitate various mineral phases on their surfaces is well documented. If this ability to influence metal partitioning to the solid phase, with an eye towards subsequent removal of this solid metal capture phase from aquatic systems, can be quantified and understood mechanistically then microbes will represent a powerful tool for environmental cleanup of aqueous environments. We evaluated the partitioning of Sr between the solid and solution phases under differing concentration (10-4 to 10-6 M) and pH (6-8) gradients in the presence of Shewenella (BrY) and hydrous ferric oxides (HFOs) both common geochemically active constituents of groundwater systems, and compared that to chemical controls in the laboratory. Experiments were run under non growth conditions (BrY cell density equal to an optical density of 0.2) using a 2 hour incubation time and Sr concentrations were analyzed by flame atomic absorption. HFOs (50 mmolar total Fe concentration used in the experiments) were always prepared fresh and used within 24 hours of preparation to avoid aging associated changes in sorptive characteristics. Control treatments (Sr alone) were run under identical conditions to those used with BrY and HFO treatments. A clear enhancement of solid phase Sr partitioning was observed with both the bacterial and HFO treatment. We will present these results and discuss their implications in the context of surface precipitation modeling.
Subjects:Alkaline earth metals; Bioremediation; Controls; Experimental studies; Ground water; Isotope ratios; Isotopes; Metals; Models; Partitioning; Plantae; Pollutants; Pollution; Quantitative analysis; Radioactive isotopes; Remediation; Solutions; Sorption; Sr-87/Sr-86; Stable isotopes; Strontium; Thallophytes; Bacteria; Ferric oxide; Shewenella
Record ID:1999005401
Copyright Information:GeoRef, Copyright 2018 American Geosciences Institute. Reference includes data supplied by the Geological Society of America, Boulder, CO, United States
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