Speciation of technetium in ground water has been studied for understanding the migration behaviour of this radionuclide in
deep geological formations. A combination of free-liquid electromigration, ion exchange, solvent extraction, coprecipitation
and dialysis methods has been applied. Both oxic and anoxic conditions have been employed. Systems studied include leaching
of sodium borosilicate glass spiked with99Tc and95mTc followed by its passage through glauconitic sand columns, and dialysis of TcO2 with ground water, sodium chloride, and humic acid solutions. Results indicate the presence of the pertechnetate, TcO
, ion as the dominating species.