Published February 2016 | Version v1
Journal article Metadata-only

Speciation and valence of Np in balanced system of Np-groundwater-bentonite

Creators

  • 1. China Institute of Atomic Energy, Beijing (China)

Description

The speciation and valence distributions and effect of pH on the speciation and valence distributions of Np in the balanced system of Np-groundwater-bentonite were studied by batch experiments and solvent extraction methods. The results indicate that the valence of Np in groundwater is penta-valent state, and tetra- and penta-valent states were obtained on bentonite. With the increase of pH, the percentage of Np(Ⅴ) in bentonite increases at first and then decreases at pH > 9. With the increase of CO32-, the percentage of Np(Ⅴ) in bentonite decreases. The calculation results of PHREEQCI show that NpO2+ is the main speciation of Np at pH < 9, and NpO2OH at pH > 9. NpO2(CO3)23- and NpO2(CO3)35- are the main speciations of Np at high concentration CO32- solution. The valence of Np is not affected by pH. (authors)

Additional details

Identifiers

DOI
10.7538/yzk.2016.50.02.0242;

Publishing Information

Journal Title
Atomic Energy Science and Technology
Journal Volume
50
Journal Issue
2
Journal Page Range
p. 242-246
ISSN
1000-6931

INIS

Country of Publication
China
Country of Input or Organization
China
INIS RN
51032839
Subject category
S58: GEOSCIENCES;
Descriptors DEI
BENTONITE; CARBONATES; CONCENTRATION RATIO; DISTRIBUTION; GROUND WATER; NEPTUNIUM; NEPTUNIUM OXIDES; PH VALUE; SOLVENT EXTRACTION; VALENCE
Descriptors DEC
ACTINIDE COMPOUNDS; ACTINIDES; CARBON COMPOUNDS; CHALCOGENIDES; CLAYS; DIMENSIONLESS NUMBERS; ELEMENTS; EXTRACTION; HYDROGEN COMPOUNDS; INORGANIC ION EXCHANGERS; ION EXCHANGE MATERIALS; MATERIALS; METALS; MINERALS; NEPTUNIUM COMPOUNDS; OXIDES; OXYGEN COMPOUNDS; SEPARATION PROCESSES; SILICATE MINERALS; TRANSURANIUM COMPOUNDS; TRANSURANIUM ELEMENTS; WATER

Optional Information

Notes
7 figs., 3 tabs., 13 refs.; http://dx.doi.org/10.7538/yzk.2016.50.02.0242