99Tc is formed mostly during nuclear reactions and is released into the environment during weapons testing and inadvertent waste disposal. The long half-life, high environmental mobility (as Tc(VII)O4-) and its possible uptake into the food chain cause 99Tc to be a significant environmental contaminant. In this study, we evaluated the role of Fe(II) in biologically reduced clay mineral, nontronite (NAu-2), in reducing Tc(VII)O4- to poorly soluble Tc(IV) species as a function of pH and Fe(II) concentration. The rate of Tc(VII) reduction by Fe(II) in NAu-2 was higher at neutral pH (pH 7.0) than at acidic and basic pHs when Fe(II) concentration was low (
Revised: May 22, 2009 |
Published: June 20, 2009
Citation
Jaisi D.P., H. Dong, A.E. Plymale, J.K. Fredrickson, J.M. Zachara, S. Heald, and C. Liu. 2009.Reduction and long-term immobilization of technetium by Fe(II) associated with clay mineral nontronite.Chemical Geology 264, no. 1-4:127-138.PNNL-SA-65652.doi:10.1016/j.chemgeo.2009.02.018