Journal article
Speciation of Fe(II) and Fe(III) in Contaminated Aquifer Sediments Using Chemical Extraction Techniques
The iron mineralogy of aquifer sediments was described by chemical extraction techniques. Single-step extractions including 1 M CaC12, NaAc, oxalate, dithionite, Ti(II1)- EDTA, 0.5 M HC1,5 M HC1, hot 6 M HC1, and a sequential extraction by HI and CrIIHC1 were tested on standard iron minerals and nine aquifer sediments from different redox environments sampled in a landfill leachate plume.
Ion-exchangeable Fe(I1) is easily quantified by anaerobic CaClz extraction. A rapid indication of the redox status of a sediment sample can be achieved by a 0.5 M HC1 extraction. This extraction gives an indication of the content of amorphous Fe(II1) and reduced Fe(I1) species such as FeS and FeC03, though the fractions are not quantified.
A good estimate of the iron(II1) oxide content contributing to the oxidation capacity (OXC) of the sediment is given by the Ti(II1)-EDTA extraction. The iron(I1) sulfide species are distinguished as AVS (acid volatile sulfide, hot 6 M HC1 extraction) and pyrite (sequential HI and CrIIHC1 extraction).
By including a cold 5 M HC1 extraction, the total distribution of the major reactive Fe(I1) and Fe(II1) fractions in aquifer sediments can be assessed.
Language: | English |
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Publisher: | American Chemical Society |
Year: | 1994 |
Pages: | 1698-1705 |
ISSN: | 15205851 and 0013936x |
Types: | Journal article |
DOI: | 10.1021/es00058a023 |
ORCIDs: | Christensen, Thomas Højlund |