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Titolo:
Laboratory migration experiments with radionuclides and natural colloids in a granite fracture
Autore:
Vilks, P; Baik, MH;
Indirizzi:
Atom Energy Canada Ltd, Whiteshell Labs, Pinawa, MB R0E 1L0, Canada Atom Energy Canada Ltd Pinawa MB Canada R0E 1L0 inawa, MB R0E 1L0, Canada Korea Atom Energy Res Inst, Taejon 305600, South Korea Korea Atom Energy Res Inst Taejon South Korea 305600 305600, South Korea
Titolo Testata:
JOURNAL OF CONTAMINANT HYDROLOGY
fascicolo: 2-4, volume: 47, anno: 2001,
pagine: 197 - 210
SICI:
0169-7722(200102)47:2-4<197:LMEWRA>2.0.ZU;2-4
Fonte:
ISI
Lingua:
ENG
Soggetto:
SUSPENDED PARTICLES; SORPTION;
Keywords:
natural colloids; radionuclide transport; granite fracture;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Agriculture,Biology & Environmental Sciences
Citazioni:
11
Recensione:
Indirizzi per estratti:
Indirizzo: Vilks, P Atom Energy Canada Ltd, Whiteshell Labs, Pinawa, MB R0E 1L0, Canada Atom Energy Canada Ltd Pinawa MB Canada R0E 1L0 R0E 1L0, Canada
Citazione:
P. Vilks e M.H. Baik, "Laboratory migration experiments with radionuclides and natural colloids in a granite fracture", J CONTAM HY, 47(2-4), 2001, pp. 197-210

Abstract

Natural colloids in groundwater could facilitate radionuclide transport, provided the colloids are mobile, are present in sufficient concentrations and can adsorb radionuclides, This paper describes the results of a laboratory migration study carried out with combinations of radionuclides and natural colloids within a fracture in a large granite block to experimentally determine the impact of colloids on radionudide transport. The Sr-85 used in this study is an example of a moderately sorbing radionuclide, while the Am-241 is typical of a strongly sorbed radionuclide with very low solubility,The natural colloids used in this study were isolated from granite groundwater from Atomic Energy of Canada (AECL) Underground Research Laboratory (URL), and consisted of mostly 1-10 nm organic colloids, along with lesser amounts of 10-450 nm colloids (organics and aluminosilicates), The measured coefficients for radionuclide sorption onto these colloids were between 3 x 10(2) and 1 X 10(3) ml/g for Sr-85, and between 7 X 10(4) and 7 X 10(5) mg/l for Am-241, The Sr-85 sorption on the natural colloids appeared to be reversible. Migration experiments in the granite block were carried out by establishing a flow field between two boreholes tout of a total of nine) intersecting a main horizontal fracture. These experiments showed that dissolved85Sr behaved as a moderately sorbing tracer, while dissolved Am-241 was completely adsorbed by the fracture surfaces and showed no evidence of transport. However, when natural colloids were injected together with dissolved Am-241, a small amount of Am-241 transport was observed, demonstrating the ability of natural colloids to facilitate the transport of radionuclides with low solubility. Natural colloids had only a minor effect on the transportof Sr-85. In a separate experiment to test the effect of higher colloid concentrations on Sr-85 migration, synthetic colloids were produced from Avonlea bentonite. The introduction of a relatively high concentration of bentonite colloids actually reduced Sr-85 transport because, compared to naturalcolloids, the bentonite colloids were less mobile and they sorbed Sr-85 more strongly. (C) 2001 Elsevier Science B.V. All rights reserved.

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Documento generato il 12/07/20 alle ore 02:54:18