Journal article
Fe(II)-Catalyzed Transformation of Organic Matter-Ferrihydrite Coprecipitates: A Closer Look Using Fe Isotopes
Environmental science & technology, Vol.52(19), pp.11142-11150
10/02/2018
DOI: 10.1021/acs.est.8b03407
PMID: 30189730
Abstract
Ferrihydrite is a common Fe mineral in soils and sediments that rapidly transforms to secondary minerals in the presence of Fe(II). Both the rate and products of Fe(II)-catalyzed ferrihydrite transformation have been shown to be significantly influenced by natural organic matter (NOM). Here, we used enriched Fe isotope experiments and
Fe Mössbauer spectroscopy to track the formation of secondary minerals, as well as electron transfer and Fe mixing between aqueous Fe(II) and ferrihydrite coprecipitated with several types of NOM. Ferrihydrite coprecipitated with humic acids transformed primarily to goethite after reaction with Fe(II). In contrast, ferrihydrite coprecipitated with fulvic acids and Suwannee River NOM (SRNOM) resulted in no measurable formation of secondary minerals. Despite no secondary mineral transformation, Mössbauer spectra indicated electron transfer still occurred between Fe(II) and ferrihydrite coprecipitated with fulvic acid and SRNOM. In addition, isotope tracer experiments revealed that a significant fraction of structural Fe in the ferrihydrite mixed with the aqueous phase Fe(II) (∼85%). After reaction with Fe(II), Mössbauer spectroscopy indicated some subtle changes in the crystallinity, particle size, or particle interactions in the coprecipitate. Our observations suggest that ferrihydrite coprecipitated with fulvic acid and SRNOM remains a highly dynamic phase even without ferrihydrite transformation.
Details
- Title: Subtitle
- Fe(II)-Catalyzed Transformation of Organic Matter-Ferrihydrite Coprecipitates: A Closer Look Using Fe Isotopes
- Creators
- Zhe Zhou - University of IowaDrew E Latta - University of IowaNadia Noor - University of GeorgiaAaron Thompson - Department of Crop & Soil Sciences , The University of Georgia , Athens , Georgia 30602 , United StatesThomas Borch - Colorado State UniversityMichelle M Scherer - University of Iowa
- Resource Type
- Journal article
- Publication Details
- Environmental science & technology, Vol.52(19), pp.11142-11150
- DOI
- 10.1021/acs.est.8b03407
- PMID
- 30189730
- ISSN
- 0013-936X
- eISSN
- 1520-5851
- Grant note
- DOI: 10.13039/100000160, name: Division of Earth Sciences, award: EAR-1451508; DOI: 10.13039/501100004543, name: China Scholarship Council
- Language
- English
- Date published
- 10/02/2018
- Academic Unit
- Civil and Environmental Engineering; IIHR--Hydroscience and Engineering
- Record Identifier
- 9984197253102771
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