In situ sorption of technetium using activated carbon

The sorption of technetium in pertechnetate form on carbon has been investigated. The sorption is pH dependent with maximal distribution coefficients, Kd, in the order of 10(6) at pH 2-4 for activated carbon with a grain size < or = 100 microm. The equilibrium time to reach such distribution coefficient was about 5 h at room temperature. The exact mechanisms for the sorption are not fully understood but reduction of Tc by the carbon might be an important process. Technetium can effectively and rapidly (5 l min(-1)) be sorbed from very large volumes (several hundred liters) of environmental waters on commercial cartridge filters impregnated with activated carbon. After incineration, the filters can be analyzed for 99Tc by conventional methods.