In order to address the issue of differing water contents in the samples, the water content was subtracted from the total oxide composition and the remainder was used to “adjust” or normalize the proportioning of the other components. [...] 2018) 19 Monitoring of the electrical conductivity of the freshwater side and repeated replacement of the external reservoir solution with deionized water allowed for removal of almost all the soluble ions from the MX80 and measuring of the reservoir fluid’s electrical conductivity and total dissolved solids (TDS), allowed for determination of the endpoint regarding soluble cation removal. [...] The exposure of the bentonite to brine solutions having high TDS, higher Ca and K to Na ratios relative to the raw materials will result in the release of much of the Na component (with corresponding decrease in Na in the desalinated specimen) and sorption of Ca and K to replace of the released Na (with corresponding increase in Ca and K in the XRF values of the desalinated specimen). [...] This means that the values reported for the raw samples reflect the sum of the total “natural” soluble salts and exchangeable cations present in the MX80 as well as the structural components in the mineral solids. [...] As anticipated, following soaking of the MX80 in SR-Sh brine and subsequent desalination of the samples, there is a notable reduction in the Na and increase in the Ca and K present in the remaining specimen following drying.
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- Pages
- 158
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- Canada
