Interim Report - Hanford Site

Spectrum O Na Al P Ca Cu U Total
1 47.717 0.805 11.899 16.003 23.576 100
2 32.031 0.259 8.470 5.800 0.465 52.976 100
3 39.003 0.252 7.634 4.749 48.361 100
4 38.778 0.765 0.156 11.88 15.03 33.389 100
5 34.351 0.282 8.274 6.311 0.511 50.272 100
Max. 47.717 0.805 0.282 11.899 16.003 0.511 52.976
Min. 32.031 0.765 0.156 7.634 4.749 0.462 23.576
All results in weight%.
Figure 23. A Scanning Electron Photomicrograph of Hydroxyapatite in Apatite-Equilibrated Water
Reacted with 100 ppm Uranium at pH 7
3.3.4 Column Transport Experiments
Column experiments were conducted to quantify the efficacy of an in situ hydroxyapatite barrier on
the retardation and retention of uranium. Sorption of uranium during transport, or retardation, R ef , was
calculated from the experimental BTC using moment analysis, which is based on the center-of-mass and
area under the BTC (Valocchi 1984; 1985). Apparent K d values, K d-ap , were calculated from R ef , as
follows
θ
K d − ap
= ( Ref
−1)
(16)
ρ
b
where θ is the volumetric water content and ρ b is the bulk density.
3.25