In situ redeposition of trace metals mobilized by CO2-charged brines

Wigley, Max and Kampman, Niko and Chapman, Hazel and Dubacq, Benoit and Bickle, Mike (2013) In situ redeposition of trace metals mobilized by CO2-charged brines. Geochemistry, Geophysics, Geosystems, 14 (5). 1321–1332. ISSN 1525-2027

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Abstract

Mobilization of contaminants by CO2-charged brines is one concern relating to injection of CO2 as part of carbon capture and storage projects. This study monitors the mobility of trace metals in an exhumed CO2-charged aquifer near the town of Green River, Utah (USA), where CO2-charged brines have bleached red sandstones, and concentrated trace metals at the bleaching reaction front. Mass balance calculations on the trace metal enrichments are used to calculate time-integrated fluid fluxes and show that a significant fraction of the metals mobilized by the CO2-rich brines are redeposited locally. A sequential extraction procedure on metal-enriched samples shows that these metals are incorporated into secondary carbonate and oxide phases which have been shown to grow at the CO2-promoted bleaching reaction front. We argue that while CO2-charged brines are capable of mobilizing trace metals, local metal redeposition implies that the potential for contamination of overlying freshwater aquifers is low.

Item Type:
Journal Article
Journal or Publication Title:
Geochemistry, Geophysics, Geosystems
Additional Information:
©2013. American Geophysical Union. All Rights Reserved.
Uncontrolled Keywords:
/dk/atira/pure/subjectarea/asjc/1900/1908
Subjects:
ID Code:
66484
Deposited By:
Deposited On:
17 Sep 2013 08:12
Refereed?:
Yes
Published?:
Published
Last Modified:
05 Jul 2020 03:46