Sorption of technetium on hematite colloids, at varying pH (3–10), has been studied in absence and presence of humic acid
using 95mTc-96Tc radiotracers. Technetium was found to be weakly sorbed on hematite at lower pH (<5) values, while no sorption was observed
at higher pH values. Humic acid was found to have no effect on the sorption of technetium on hematite under aerobic conditions,
while at lower pH values small reduction was observed which was attributed to the reduced zeta potential of the hematite colloids
owing to the strong sorption of humic acid.