skip to main content

Title: Microbially-Mediated Subsurface Calcite Precipitation for Removal of Hazardous Divalent Cations

We are investigating microbially-mediated acceleration of calcite precipitation and co-precipitation of hazardous divalent cations (e.g., 90Sr) in calcite saturated subsurface systems. In theory, the addition of urea to an aquifer or vadose zone and its subsequent hydrolysis by indigenous microbes will cause an increase in alkalinity, pH and calcite precipitation. Lab studies indicated the ability of various bacteria to precipitate calcite through urea hydrolysis and that incorporation of strontium in biogenically-formed calcite is greater than in abiotically formed calcite. Results from a field experiment in a pristine location in the Snake River Plain aquifer involving the phased addition of molasses and then urea showed increases in total cell numbers, rate of urea hydrolysis and calcite formation during the study. The combined diagnostic approaches of microbiology, molecular ecology and analytical chemistry demonstrate the feasibility of this biogeochemical manipulation for subsurface remediation at arid Western DOE sites such as Hanford and INEEL.
Authors:
; ; ; ; ; ; ; ; ; ; ; ;
Publication Date:
OSTI Identifier:
826394
Resource Type:
Conference
Resource Relation:
Conference: 225th American Chemical Society Meeting, New Orleans, LA (US), 03/23/2003--03/27/2003; Other Information: PBD: 27 Mar 2003
Research Org:
Idaho National Engineering and Environmental Lab., Idaho Falls, ID; University of Idaho, Idaho Falls, ID; University of Toronto, Toronto, Ontario, Canada; Portland State University, Portland, OR; Idaho State University, Pocatello, ID (US)
Sponsoring Org:
USDOE Office of Science (SC) (US)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; 54 ENVIRONMENTAL SCIENCES; ACCELERATION; ACID NEUTRALIZING CAPACITY; AQUIFERS; BACTERIA; CALCITE; CATIONS; CHEMISTRY; ECOLOGY; HYDROLYSIS; MOLASSES; PRECIPITATION; REMOVAL; SNAKE RIVER PLAIN; STRONTIUM; UREA