線香エアロゾルを用いた放射性元素状ヨウ素ガスの吸着特性の研究
1987 年 22 巻 1 号 p. 21-30
詳細
1987 年 22 巻 1 号 p. 21-30
Adsorption of radioactive elemental iodine gas (131I2) on incense stick aerosol particles has been studied to provide basic data for a realistic and precise assessment of dose to the public due to radio-iodine released from nuclear facilities.
A mixture of iodine gas and aerosol was passed once through a glass vessel to cause the adsorption reaction. The adsorption was studied at different reaction times, initial I2 gas concentrations and particle number concentrations.
The results showed that the adsorption reached an equilibrium in about 2min at the initial I2 gas concentration of 10-10g/cm3. The proportion of iodine adsorbed by the aerosol particles was almost constant, about 25% at the initial I2 gas concentrations below 10-11g/cm3 and at the reaction time of 1min, and decreased with increase of the initial concentration over 10-11g/cm3.
The adsorption isotherm of the aerosol for the gas was obtained from the experimental data. The semi-empirical equations to explain the adsorption reaction were also obtained based on the experimental data and the FUCHS's equation relating to vaporization of a droplet. The sticking probability in the equations was estimated to be 7.6×10-3. The calculated results using the equations were in good agreement with the experimental ones.
