Migration of Iodine in Beishan Granite Studied by Inject-Pulse Column Method

¹²⁹I is an important fission product which is easy to be released into the environment by the nuclear power plants. Its movement in environment causes a lot of attention all around the world. In this work, the migration of ¹²⁵I (as a substitute of ¹²⁹I) in Beishan granite was studied by an inject-pulse column method. The results show that the dominant mechanisms of iodine migration are convection and dispersion. The dispersion coefficient (D) of iodine increases with the increase of the flow velocity or the decrease with pH. The change tendency of D with pH is coincide with the surface charge distribution of Beishan granite. D is 3.29×10^-5m²·min^-1 when flow velocity is 0.07 mL·min^-1 and pH is 8.0. This result verifies the conclusion that dispersion coefficient only relates to the migration media.