Bulk solubility and speciation of plutonium(VI) in phosphate-containing solutions

Conference · Wed Jan 01 04:00:00 EST 1992

OSTI ID:6903694

Weger, H T; Okajima, S; Cunnane, J C; Reed, D T

The solubility and speciation of Pu(VI) with phosphate as a function of pH was investigated to determine the ability of phosphate to act as an actinide getter. The general properties were first investigated and are reported here with the goal of performing more quantitative experiments in the future. Solubility was approached from oversaturation at initial pH = 4, 10 and 13.4. Absorption spectra were recorded, the solution filtered and the filtrate counted. Absorption spectra were obtained at varying phosphate concentrations and at pH of 2.7 to 11.9. The effect of complexation on the 833 mn Pu(VI) band was characterized. Evidence for three phosphate complexes was obtained for pH < 10 which have absorption bands at 842, 846 and 849 mn. Evidence for colloid formation was observed but is not conclusive. The possibility of colloids prevents accurate analysis of the solubility experiments. A concentration of 10[sup [minus]5] to 10[sup [minus]6] M Pu(VI) was measured in the filtrate at pH [le] 10 that were passed through a 50 mn filter. Pu(VI) complexes with phosphate over hydroxide at pH [le] 11.6, but at pH [ge] 11.9, only hydrolyzed Pu(VI) was detected. At pH = 12, the concentration of Pu(VI) was as high as 10[sup [minus]4] M.

• Research Organization: Argonne National Lab., IL (United States)
• Sponsoring Organization: DOE; USDOE, Washington, DC (United States)
• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 6903694
• Report Number(s): ANL/CMT/CP-78233; CONF-921101--19; ON: DE93004847
• Country of Publication: United States
• Language: English

Related Subjects

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
400702* -- Radiochemistry &amp; Nuclear Chemistry-- Properties of Radioactive Materials
ABSORPTION SPECTRA
ACTINIDE COMPLEXES
ACTINIDES
AQUEOUS SOLUTIONS
COLLOIDS
COMPLEXES
DISPERSIONS
ELEMENTS
METALS
MIXTURES
OXYGEN COMPOUNDS
PH VALUE
PHOSPHATES
PHOSPHORUS COMPOUNDS
PLUTONIUM
PLUTONIUM COMPLEXES
SOLUBILITY
SOLUTIONS
SPECTRA
TRANSURANIUM COMPLEXES
TRANSURANIUM ELEMENTS