abstract
- In order to understand the fixation mechanism of IO3- in ettringite, we studied the desorption behavior of IO3- from the IO3- sorbed ettringite and the IO3- type synthesized ettringite which was prepared by using IO3- instead of SO42-. Desorption behavior of IO3- was discussed by using distilled water, KOH (pH10.6) solution, 20 mM-K2SO4+KOH (pH10.6) solution, 20 mM-K2SO3+KOH (pH10.6) solution, and ettringite equilibrium solution, and it was found that the ettringite-like structure was preserved during the desorption reactions and that desorption fractionation of IO3- was about 1 to 7 % of total amounts of IO3- sorbed in ettringite. Change in the lattice constants of ettringite-like structure was evaluated for the the IO3- sorbed ettringite when IO3- was desorbed by 0.4 M-K2SO4+KOH (pH10.6) solution for one day, and the good correlation between the lattice constant change and the desorption amount of IO3- was observed.