The effect of biogenic Fe(II) on the stability and sorption of Co(II)EDTA{sup 2{minus}} to goethite and a subsurface sediment
Laboratory experiments were conducted with suspensions of goethite ({alpha}-FeOOH) and a subsurface sediment to assess the influence of bacterial iron reduction on the fate of Co(II)EDTA{sup 2{minus}}, a representative metal-ligand complex of intermediate stability (log K{sub Co(II)EDTA} = 17.97). The goethite was synthetic (ca. 55 m{sup 2}/g) and the sediment was a Pleistocene age, Fe(III) oxide-containing material from the Atlantic coastal plain (Milford). Shewanella alga strain BrY, a dissimulatory iron reducing bacterium (DIRB), was used to promote Fe(III) oxide reduction. Sorption isotherms and pH adsorption edges were measured for Co{sup 2+}, Fe{sup 2+}, Co(II)EDTA{sup 2{minus}}, and Fe(II)EDTA{sup 2{minus}} on the two sorbents in 0.001 mol/L Ca(ClO{sub 4}){sub 2} to aid in experiment interpretation. It is concluded that cationic radionuclides such as {sup 60}Co or {sup 239/240}Pu, which may be mobilized from disposed wastes by complexation with EDTA{sup 4{minus}}, may become immobilized in groundwater zones where dissimilatory bacterial iron reduction is operative.
- Research Organization:
- Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
- OSTI ID:
- 20062606
- Journal Information:
- Geochimica et Cosmochimica Acta, Vol. 64, Issue 8; Other Information: PBD: Apr 2000; ISSN 0016-7037
- Country of Publication:
- United States
- Language:
- English
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