Microbial-mineral interaction during freezing process
Abstract
Dissolution of Fe from iron oxides and Fe-bearing clay minerals through biotic/abiotic process is of important as a source of bioavailable iron in Antarctic region. In the present study, the dissolution of iron oxide particles during freezing process was investigated as a new pathway of iron supply. Batch experiments of microbe-mineral interaction under the various temperatures (from 4 ° to -4 °, pH 7) were performed to understand the mechanism of biogeochemical dissolution of iron oxides at the seasonal temperature changes in Antarctic region. The dissolution of iron oxides by microbial Fe-respiration in aqueous phase may accelerate the Fe-dissolution accompanying with the abiotic "freeze concentration effect" in the ice phase. The dissolved iron under aqueous phase was mainly in the ferrous form, which indicates that the dissolution was induced by a reductive process. The enhanced dissolution of iron oxides in ice phase is mainly ascribed to the "freeze concentration effect" (Kim et al., 2012) which concentrates iron oxide particles, organic ligands, and protons in the liquid like ice grain boundary region and accelerates the dissolution of iron oxides. The association of microbial Fe-reduction at low temperature in Fe-dissolution will be discussed.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2016
- Bibcode:
- 2016AGUFM.B41C0446J
- Keywords:
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- 0414 Biogeochemical cycles;
- processes;
- and modeling;
- BIOGEOSCIENCESDE: 0428 Carbon cycling;
- BIOGEOSCIENCESDE: 0470 Nutrients and nutrient cycling;
- BIOGEOSCIENCESDE: 0475 Permafrost;
- cryosphere;
- and high-latitude processes;
- BIOGEOSCIENCES