This paper shows that natural materials such as barks can successfully replace synthetic
resins for industrial purposes. Evaluated in batch conditions, biosorption of uranium on
suitably prepared Douglas fir barks took place in less than 10 min and appeared to be
optimum at pH>4. The biosorption process of uranium (uranyl form
was characterized in the optimal physico-chemical conditions and could be mathematically
modeled as a Langmuir isotherm. With a maximum uranium specific uptake
qmaxvalue of 1.16 meq.g-1 (138
mgU.g-1) it was found that the sorption capability of Douglas fir barks was
at least five times higher for uranium than for other heavy metals such as lead.
Adsorption of uranium contained in water leached from a former uranium mine was then
monitored over a one-month period in a laboratory-scale chromatography column. The
fixation capacity remained fairly constant throughout the whole testing period. Water
radioactivity decreased from 1500 mBq.L-1 (0.12 mgU.L-1) to
<5 mBq.L-1(0.4 μ gU.L-1) at the column
exit. This technology was successfully transferred and tested through a pilot project
under industrial conditions with the support of AREVA NC.