Quantitative mechanistic description of Ni, Zn and Ca sorption on Na-Montmorillonite. Part II: Sorption measurements

摘要

The main focus of the experimental work presented here is the sorption behavior of Ni on conditioned Na-montmorillonite. Ca and Zn were also studied as important background impurity cations which can, depending on the circumstances, be competitive for the available sorption sites. Distribution ratios were measured for all three radionuclides at trace concentrations as a function of pH over a range from 2 to 10.5 to produce so-called 'sorption edges'. In the cases of Ca and Ni such measurements were carried out as a function of the NaClO4 background electrolyte concentration. In addition to sorption edges, sorption isotherms were determined for Ni and Zn in solutions of 0.1 M NaClO4 at several pH values. The non-linear sorption isotherms indicated that in addition to cation exchange, at least 2 different sites identical to SOH sites were present in Na-montmorillonite contributing to the overall sorption. (author) 22 figs., 10 tabs., refs. (Atomindex citation 26:069191)