Technetium, as technetium -99, is present in environmental
waters as a result of radioactive effluent discharges from nuclear
It is necessary to be able to measure aqueous technetium levels
if accurate models are to be developed to predict the long term effects
of technetium releases on man. As natural waters contain little
technetium, less than μg dm-3 ,relatively large samples are required
( >500 cm3). A method has been developed in which the technetium in
the sample can be rapidly concentrated onto an anion-exchange column
after the removal of ruthenium isotopes by a precipitation procedure.
Further decontamination is achieved by washing the anion-exchange resin
with sodium hydroxide prior to removing the technetium with sodium
thiocyanate. The bulk of the concentrated technetium (> 75%) can be
removed from the resin into less than 15 cm
of eluent and further concentration
is achieved by extracting the technetium into butan-2-one.
The butan-2-one can be evaporated onto a planchette and the technetium
levels determined by measuring the amount of B-radiation emitted from
the final concentrate. The method has been shown to be capable of
removing between ca. 10-15 g and 10 -6 g of technetium from 500 cm 3 of
water and has been used successfully with samples ranging from natural
waters to nuclear installation effluent.
Technetium in natural waters may be lost from solution onto soils
and this has important consequences if environmental technetium levels
are to be measured. Experiments have been carried out to investigate
Some of the factors which influence technetium sorption onto soil and
microbial action has been shown to play an important role in determining
the rate at which technetium is lost from solution. Other parameters
found to affect technetium sorption onto soil include the chemical form
of the technetium and the type of water used in the experiment.
A Doctoral Thesis. Submitted in partial fulfilment of the requirements for the award of Doctor of Philosophy of Loughborough University.