Effect of the degree of supersaturation upon apparent partition coefficients of lead and strontium ions between BaSO₄ and aqueous solution

Abstract

Apparent partition coefficients of lead and strontium between barium sulfate and aqueous solution were determined under various conditions changing temperatures, chloride concentrations and degrees of supersaturation of the solution with respect to BaSO₄.
It was found that the apparent partition coefficients of lead and strontium are largely controlled by the degree of supersaturation of aqueous solution with BaSO₄ as well as temperature and chloride concentration.
The coefficients for lead ranged from 0.034 to 0.22 when initial solutions contain 0.004 mole/1 to 0.00025 mole/1 of barium plus lead ions in BaSO₄–PbSO₄ binary series. In the BaSO₄–PbSO₄–SrSO₄ ternary series, the coefficients for lead were from about 0.1 to 0.6 when the total cations in the initial solution changed from 0.0024 mole/1 to 0.0006 mole/1 and 0.05 to 0.15 with 0.05 mole/1 chloride ion. The values for strontium are from 4.1×10⁻³ to 1.5×10⁻² with the same change of the total cation concentration in the solution.
These experimental results were consistent with the partition of lead and strontium between Tamagawa Hot Spring water and hokutolite when the coefficients are related with barium and sulfate concentration in the solution.