Stability of Organic Matter-Clay Systems in Presence of Aqueous Fe(II)
EMSL Project ID
49252
Abstract
Stabilization of soil organic matter (SOM) is important to sequestrate carbon and mitigate greenhouse gas emissions. The factors that govern this stabilization and preservation of OM, under redox conditions, however, are not well studied casting shadow on predicting the response of soil under varying conditions to climate change. The extent of SOM destabilization under these conditions, if any, will be a function of many parameters, e.g., the type of SOM, the type of mineral, the nature of SOM-mineral interaction, the SOM/mineral content, pH of the medium, and the mode of reduction/oxidation (abiotic or biotic). In case of SOM-Fe(III)-minerals, OM released upon reduction can exist in different forms. For example, as dissolved organic matter (DOM), (Fe,Al,Mg)-DOM, and OM sorbed onto secondary minerals. Furthermore, these pools of OM may be susceptible to microbial oxidation differently than the original sorbed OM. Our study will will provide fundamental understanding into a) the effects of clay reduction on OM remobilization. This is critical because OM-clays present in subsurface are prone to reduction (and reoxidation up on return of oxic conditions), and b) gain a deeper understanding of the effect of the nature of OM-clay interaction (e.g., inner-sphere OM vs. hydrophobic OM) on its stability.
Project Details
Start Date
2016-04-06
End Date
2016-09-30
Status
Closed
Released Data Link
Team
Principal Investigator
Co-Investigator(s)
Related Publications
Zhang L., H. Dong, R.K. Kukkadapu, Q. Jin, and L. Kovarik. 2019. "Electron Transfer Between Sorbed Fe(II) and Structural Fe(III) in Smectites and its Effect on Nitrate-Dependent Iron Oxidation by Pseudogulbenkiania sp. strain 2002." Geochimica et Cosmochimica Acta 265. PNNL-SA-135173. doi:10.1016/j.gca.2019.08.042