Published January 2016 | Version v1
Journal article Metadata-only

Speciation and solubility of americium in Beishan groundwater

Creators

  • 1. Sino-French Institute of Nuclear Engineering and Technology, Sun Yat-Sen University, Zhuhai (China)
  • 2. CAS Key Laboratory of Mineralogy and Metallogeny, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou (China)

Description

Based on the thermodynamic data published by OECD/NEA and the estimated saturation indices for the precipitation of secondary minerals, the influence of pH, calcite, CO2, and humic acid (HA) on the speciation distribution and solubility of Americium (Am) in Beishan groundwater were investigated using PHREEQC software. The results indicated that Am mainly occurred as AmCO3+ and AmSiO(OH)32+ at nearly neutral condition, whereas ArTiOHCO3·0.5HO(cr) and Am (OH)3(cr) became predominantly at alkaline condition. Therefore, alkaline Beishan groundwater is favorable for the retardation of Am. Calcite exhibited a complex effect on the solubility and mobility of Am. At pH 6-8, it can decrease the solubility of Am slightly; at pH 8-9.7, the formation of anionic Am (CO3)2- was favorable thus the solubility and mobility of Am increased in presence of calcite; whereas as pH increased to 9.7-11, calcite can decrease the solubility of Am because of the formation of AmOHCO2·0.5H2O(cr). When pH was fixed at 7 56, the solubility of americium decreased firstly and then increased subsequently with increasing CO2 pressure, and reached a minimum value at 10-2.25 bar. The results also indicated that humic acid had strong affinity towards americium, and from nearly acidic to alkaline conditions it could increase the solubility and hence the mobility of americium. (authors)

Additional details

Publishing Information

Journal Title
Radiation Protection (Taiyuan)
Journal Volume
36
Journal Issue
1
Journal Page Range
p. 40-46
ISSN
1000-8187

INIS

Country of Publication
China
Country of Input or Organization
China
INIS RN
52043846
Subject category
S12: MANAGEMENT OF RADIOACTIVE WASTES, AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES;
Descriptors DEI
AFFINITY; AMERICIUM; AMERICIUM CARBONATES; AMERICIUM COMPLEXES; CARBONATES; CHEMICAL STATE; COMPUTER CODES; DATA; DISTRIBUTION; GROUND WATER; HUMIC ACIDS; MOBILITY; P CODES; PH VALUE; PRECIPITATION; RADIOACTIVE WASTE DISPOSAL; SATURATION; SOLUBILITY; THERMODYNAMICS
Descriptors DEC
ACTINIDE COMPLEXES; ACTINIDE COMPOUNDS; ACTINIDES; AMERICIUM COMPOUNDS; CARBON COMPOUNDS; CARBONATES; COMPLEXES; COMPUTER CODES; ELEMENTS; HYDROGEN COMPOUNDS; INFORMATION; MANAGEMENT; METALS; ORGANIC ACIDS; ORGANIC COMPOUNDS; OXYGEN COMPOUNDS; RADIOACTIVE WASTE MANAGEMENT; SEPARATION PROCESSES; TRANSPLUTONIUM COMPOUNDS; TRANSPLUTONIUM ELEMENTS; TRANSURANIUM COMPLEXES; TRANSURANIUM COMPOUNDS; TRANSURANIUM ELEMENTS; WASTE DISPOSAL; WASTE MANAGEMENT; WATER

Optional Information

Notes
6 figs., 2 tabs., 23 refs.