1974 年 9 巻 4 号 p. 211-217
Some characteristics of I2-gas relevant to its transportation in earths were investigated.
The sorption was studied by passing 131I loaded I2-gas through thin beds of earth samples under various conditions of the temperature and relative humidity. Desorption was examined by sweeping these beds with dry air and by leaching with water. Some of the results are (1) sorption is large for dry earths, while it becomes much smaller with increase of moisture, (2) a variety of desorptivity was observed, still the remaining quantity at the end of water leaching was nearly independent of the kind of samples and of experimental conditions, and (3) sorption increases linearly at first and tends to saturation, where the limit of linearity will correspond to the adsorption with monomolecular layer.
The transportation behavior was studied by passing I2-gas through a 35cm tube filled with the earth sample. The time-dependent distribution of iodine was obtained radiologically. The result is approximately expressed by a transport equation taking the Henry type adsorption and the chemisorption into account.