KINETICS AND THERMODYNAMICS OF U-REDUCTION BY NATURAL AND SIMPLE ORGANIC-MATTER

Nakashima, S

HERO ID

4936963

Reference Type

Journal Article

Year

1992

HERO ID 4936963
In Press No
Year 1992
Title KINETICS AND THERMODYNAMICS OF U-REDUCTION BY NATURAL AND SIMPLE ORGANIC-MATTER
Authors Nakashima, S
Journal Organic Geochemistry
Volume 19
Issue 4-6
Page Numbers 421-430
Abstract The hypothesized reaction mechanisms for U reduction by the dehydrogenation of hydroxyl groups and aliphatic hydrocarbonaceous moieties of lignite were verified by kinetic U reduction experiments using simple alcohols (1 -octadecanol and 2-propanol) and aliphatic hydrocarbons (n -octacosane). The rate constants and activation energies for U reduction by these alcohols are similar to those obtained for U reduction by lignite. The rate-determining step for U reduction by both simple and natural organic matter is hypothesized to be controlled by oxygen diffusion through U oxides. The equilibria of the system lignite-aqueous uranyl have been used to calculate standard free energy changes DELTAG-degrees for lignite dehydrogenation. Their comparison with those for the dehydrogenation of simple organic molecules supports the proposed reactions thermodynamically.
Doi 10.1016/0146-6380(92)90009-M
Wosid WOS:A1992KG33700009
Is Certified Translation No
Dupe Override No
Is Public Yes
Keyword URANIUM; LIGNITE; REDUCTION; REACTION RATES; THERMODYNAMICS; ALCOHOLS; ALIPHATIC HYDROCARBONS