ESTIMATION OF THE KINETICS OF THE EXCHANGEIZOTOPIC REACTIONS IN CLAY MINERALS
Abstract
On the base of the long-term experiments it was determined that temporal dependence of exchange-izotopic reactions between matrix water of clay minerals and initial HTO may be adequate description by be-exponential equation as fallows: At = A(1-e-k1t)+B(1-e-k2t). with validity as R = 0,97–0,99. An isotopic exchange coefficient a for different structural positions of kaolinite, montmorillonite and palygorscite were calculated. It was shown in spite of the fact that much more quantity OH-groups are in kaolinite then they are in montmorillonite and palygorscite but OThydroxyls access is more hard to the reaction positions within the mineral structure there is much less exchange between free tritium water and mineral matrix. Probable advance time of tritium peak concentrations in kaolinite, montmorillonite and palygorscite matrix OH-positions was calculated. With use of radioactive decay equation also the probable time of tritium decay to 10–20 Bq/l level when initial HTO being equal 1 MBq/l was evaluated.
References
Samodurov V.P., Hach-Ali P.F., Baker J.H., Lytovchenko A.S., Pushkarev A.V., Kovalenko G.D. Tritium labelling of phyllosilicate reactivity for clay barriers study. // European Journal of Mineralogy. — 2003. v. 15, — P. 231–234.
Несмеянов Ан.Н. Радиохимия. М.: Химия, 1972. — 592 с.
Тарасевич Ю.И. Строение и химия поверхности слоистых силикатов. Киев: Наук. думка, 1988. — 248 с.
Kalinichenko, E.A., Pushkarova, R.A., Fenoll Hach Ali, P. & L pez-Galindo, A. Tritium accumulation in the structure of some clay minerals // Clay Minerals. — 2002. — 37. — P. 497–508.
Samodurov V.P., Hach-Ali P.F., Baker J.H., Lytovchenko A.S., Pushkarev A.V., Kovalenko G.D. Tritium labelling of phyllosilicate reactivity for clay barriers study. // European Journal of Mineralogy. — 2003. v. 15, — P. 231–234.;
Tritium accumulation and preservation into phyllosilicates and mineral mixtures for environmental protection. Hach-Ali P.F., Baker J.H.,Lytovchenko A.S., Pushkarev A.V., Samodurov V.P. et al./ Final Report INTAS Project 2001–2166. — Brussels, Belgium, 2001. — Annexes. — 167 p.
A. Lopez-Galindo, P. Fenoll Hach-Ali, A.V. Pushkarev, A.S. Lytovchenko, J.H. Baker, R.A. Pushkarova Tritium redistribution between water and clay minerals //Applied Clay Science, — 2008, v.39, p. 151–159.
