THE USE OF SYNTHESIZED AQUEOUS-SOLUTIONS FOR DETERMINING STRONTIUM SORPTION ISOTHERMS

The use of synthesized aqueous solutions for determining experimentall y derived strontium sorption isotherms of sediment was investigated as part of a study accessing strontium chemical transport properties. Ba tch experimental techniques were used to determine strontium sorption isotherms using synthesized aqueous solutions designed to chemically r epresent water from a natural aquifer with respect to major ionic char acter and pH. A strontium sorption isotherm for a sediment derived usi ng a synthesized aqueous solution was found to be most comparable to a n isotherm derived using natural water when the synthesized aqueous so lution contained similar concentrations of calcium and magnesium, Howe ver, it is difficult to match compositions exactly due to the effects of disequilibrium between the solution and the sediment, Strong linear relations between sorbed strontium and solution concentrations of cal cium and magnesium confirm that these cations are important co-constit uents in these synthesized aqueous solutions. Conversely, weak linear relations between sorbed strontium and solution concentrations of sodi um and potassium indicate that these constituents do not affect sorpti on of strontium. The addition of silica to the synthesized aqueous sol ution does not appreciably affect the resulting strontium sorption iso therm. (C) 1998 Elsevier Science B.V.