Molecular Interfacial Reactions between Pu(VI) and Manganese Oxide Minerals Manganite and Hausmannite
- LBNL Library
The sorption of Pu(VI) onto manganite (MnOOH) and hausmannite (Mn3O4) was studied as a function of time, solution pH, and initial plutonium concentration. Kinetic experiments indicate that the surface complexation of plutonium occurs over the first 24 h of contact with the mineral surface. The sorption increases with pH beginning at pH 3 until it reaches a maximum value of 100 percent at pH 8 (0.0011-0.84 mumol of Pu/m(2) of manganite and 0.98-1.22 mumol of Pu/m(2) of hausmannite) and then decreases over the pH range from 8 to 10. The ratio of solid to solution was 10 mg/mL for manganite experiments and 4 mg/mL for hausmannite samples. Carbonate was not excluded from the experiments. The amount of plutonium removed from the solution by the minerals is determined by a combination of factors including the plutonium solution species, the surface charge of the mineral, and the mineral surface area. X-ray absorption fine structure taken at the Pu L-III edge were compared to plutonium standard spectra and showed that Pu(VI) was reduced to Pu(IV) after contact with the minerals. Plutonium sorption to the mineral surface is consistent with an inner-sphere configuration, and PuO2 evidence of PuO2 precipitation is observed. The reduction and complexation of Pu(VI) by manganese minerals has direct implications on possible migration of Pu(VI) species in the environment. [References: 50]
- Research Organization:
- Ernest Orlando Lawrence Berkeley National Laboratory, Berkeley, CA (US)
- Sponsoring Organization:
- USDOE Director. Office of Science. Office of Basic Energy Sciences (US)
- DOE Contract Number:
- AC03-76SF00098
- OSTI ID:
- 835987
- Report Number(s):
- LBNL--51325
- Journal Information:
- Environmental Science and Technology, Journal Name: Environmental Science and Technology Journal Issue: 15 Vol. 37; ISSN ESTHAG; ISSN 0013-936X
- Country of Publication:
- United States
- Language:
- English
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