Radiochemical studies of the sorption behavior of strontium and barium

Abstract

The sorpt ion behavior of strontium and barium on kaolinite, bentonite and chlorite-illite mixed clay was studied by radi0mralytical techniques using file batch method. 90Sr (29.1 y) and 133Ba (10.5 y) were used as radiotracers. Characterization of the solid matrices was done by FFIR and XRD spectrometries and specific surface area measurements. Synthetic groundwater was used as the aqueous phase. The variation of the distribution ratio Rd, as a function of metal ion loading was examined. The sorption isotherms were fitted to various isotherm models. The sorption energies were calculated to be in the range of 8-10 k J/tool suggesting an ion exchange type of sorption mechanism. In detailed experiments, chlorile-illite mixed clay was first presaturated with K +, Sr 2+, Ca 2+ and A13+ ions, respectively, prior to sorption studies with Ba 2+ ions. The results of Ca 2+ pretreated chlorite-illite were very similar to those of natural chlorite-iUite, suggesting that the Ba 2 § ion exchanges primarily with the Ca 2 § ion on the clay minerals.The sorption of waste radionuclides on to soil constituents, particularly on clay minerals act as a barrier to their dispersion by the groundwater. Many investigations on radionuclide migration and their sorption behavior have been carried out. 1-1~ The general objective was to understand the effects of different parameters such as composition of groundwater, its pH, structure of solid maWix on the sorption process as well as to establish a basis for the modelling and prediction of radionuclide behavior in the geological environment.In this work the sorption behavior of Sr 2 § and Ba 2* cations were studied. The results would contribute to the establishment of a data base for migration models. Furthermore, since strontium and barium are homologs of important species radium, their results could provide information about the migration behavior of radium.

Geochemical and thermodynamic aspects of sorption of strontium on kaolinite dominated clay samples at Kalpakkam

“…However, Erdal et al (1978) reported that pH does not have any major effect on Sr-sorption on granite. Gokturk et al (1995) also reported that no significant change in the sorption behavior of barium and strontium is observed between the pH range 3.0-8.5 for kaolinite and bentonite.…”

A Study on Sorption of 226Ra on Different Clay Matrices

“…Many researchers have studied the removal of radionuclides from contaminated soil using different natural and artificial materials (Cho et al 1996;Göktürk et al 1995;IAEA 1995;Khan 2003;Lee et al 1997;Misra and Mehta 1995;Plećaš et al 1991;Shahwan and Erten 2001;Wang 2003). Bentonite was widely used as an adsorbent material by several researchers (Odom 1984;Montavon et al 2006;Murali and Mathur 2002;Göktürk et al 1995;Khan 2003;Lee et al 1997).…”

“…Bentonite was widely used as an adsorbent material by several researchers (Odom 1984;Montavon et al 2006;Murali and Mathur 2002;Göktürk et al 1995;Khan 2003;Lee et al 1997). Bentonite has the ability to adsorb a large volume of water, 12-15 times the volume of dry state bentonite, thus forming a gel material.…”