Activation Energy for Diffusion of Cesium in Compacted Sodium Montmorillonite.

Self-Diffusion of Water and Ions in Clay Barriers

“…Relative apparent diffusion coefficients D a / D 0 were calculated using D 0 ¼ 2.30, 2.27, and 2.24 10 À9 m 2 s À1 for H 2 O, HDO, and HTO (Mills, 1973) and 1.33, 2.07, 0.794, 2.03, 2.01, and 2.00 10 À9 m 2 s À1 for Na þ , Cs þ , Sr 2þ , Cl À , Br À , and I À at 298 K, respectively (Li and Gregory, 1974). Kozaki et al (1996Kozaki et al ( , 1997Kozaki et al ( , 1998Kozaki et al ( , 1999bKozaki et al ( , 2001Kozaki et al ( , 2005 Smectite (KP) HTO, Na þ , Cs þ , Ca 2þ 0 (Na/Ca) 288e323 AE 0.1 1.0, 1.8 D a , E a CC Kozaki et al (1999aKozaki et al ( , 2005Kozaki et al ( , 2010 Smectite ( …”

Diffusion measurement of caesium in compacted bentonite

“…4. The apparent activation energy (E,) of Da was about 35 kJ mo1-1 and agreed with that of Kozaki [11] for Cs diffusion in pure Na montomorillonite, which was obtained from Kunigel-V 1 by purification and Na-Ca exchange procedures. Of note is that the D a values for the two bentonite samples with p of ca.…”

The concentration and pH dependent diffusion of 137Cs in compacted bentonite by using capillary method

“…Kozaki et al [6] studied the diffusion of Cs + in compacted bentonite and found that diffusion coefficients of Cs + was higher than those reported by Sato et al [1]. Kozaki et al [6] gave the reason that the difference was attributed to the difference in diffusion temperature and particle sizes of the bentonite. Kozaki et al [8] also studied the effect of bentonite particle size on diffusion of Cs + in compacted bentonite and found that diffusion coefficient decreases with decreasing particle size.…”

“…The diffusion of many radionuclides in compacted bentonite was studied and the results indicated that diffusion coefficients of radionuclides decrease with increasing bulk dry densities [1,10]. Kozaki et al [6] studied the diffusion of Cs + in compacted bentonite and found that diffusion coefficients of Cs + was higher than those reported by Sato et al [1]. Kozaki et al [6] gave the reason that the difference was attributed to the difference in diffusion temperature and particle sizes of the bentonite.…”

“…Radionuclides diffusion and its mechanisms in different compacted bentonite clays have been investigated during the last decades [5][6][7][8][9]. Kim et al [9] studied the diffusion of Cs and Sr in compacted bentonite and indicated that it can not be concluded that the cation having a higher K d value always migrates through the compacted bentonite slower than the cation having a lower K d value.…”