Iodide, caesium and strontium adsorption by organophilic vermiculite
and strontium ions (125I-, 134Cs+ and 85Sr2+) were determined in untreated vermiculite and in vermiculite treated with the chloride salt of hexadecylpyridinium (HDPy+). Experimental data reveal that some of the alkylammonium ions were incorporated asHDPyCI ion pairs into the vermiculite. The fractio...
| Main Authors: | , , |
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| Other Authors: | |
| Format: | Text |
| Language: | English |
| Published: |
1996
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| Subjects: | |
| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.599.8100 http://www.minersoc.org/pages/Archive-CM/Volume_32/32-1-21.pdf |
| Summary: | and strontium ions (125I-, 134Cs+ and 85Sr2+) were determined in untreated vermiculite and in vermiculite treated with the chloride salt of hexadecylpyridinium (HDPy+). Experimental data reveal that some of the alkylammonium ions were incorporated asHDPyCI ion pairs into the vermiculite. The fraction of ion pairs adsorbed is reflected by an increase in distribution coefficients with increasing saturation levels. Consequently, a considerable part of the iodide adsorption could be attributed toan anion exchange process. At smaller amounts of Cs § and Sr z+ adsorbed, istribution coefficients of the modified clay mineral are significantly reduced in comparison with the original material. These differences are less pronounced when greater amounts of cations are adsorbed. Generally, larger distribution coefficients were found for the Cs + compared with the Sr z § ion in the untreated and modified samples. Soils represent an important filter and buffer system for many cations and anions. Generally, their sorption properties are determined by the contents and compositions of clay minerals and humic substances. A great part of the soil organic matter is associated with clay minerals forming organo-mineral complexes (Greenland, 1965) which are of pronounced importance with respect to element transport and/or etention and to aggregate stability. Clay minerals also interact with organic cations. The replacement of inorganic ations by alkylam-monium ions causes considerable modification in the hydration and swelling properties of the clays. Research in this area has significantly increased the knowledge on the physico-chemical behaviour of both clay minerals and organo clay minerals |
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