Simultaneous diffusion of Re(VII) and Se(IV) in compacted Tamusu clay by capillary method

This paper presents the first laboratory-based, simultaneous diffusion experiments of Re(VII) and Se(IV) in Tamusu (TMS) clay, using the capillary method. We determined diffusion coefficients ( D a ) and adsorption values ( K d ) for these nuclides under varying clay compaction densities, solution pH values, ionic strengths, and in the presence of humic acid (HA). The results indicated rapid acquisition of diffusion data, the D a values predominantly ranging from 10 −9 m 2 /s to 10 −10  m 2 /s, and weak adsorption for both Re(VII) and Se(IV). While the presence of HA augmented the D a and K d values for Re(VII) and Se(IV) diffusion in clay, these values did not exhibit significant alterations in response to increasing HA concentrations.