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Abstract

The radionuclide 95m-Tc proved to be very useful as a tracer for the experimental study of the behaviour of technetium in the marine environment at realistic mass concentrations. It has been shown that, in agreement with thermodynamic considerations, the anion pertechnetate is the chemical form of technetium stable in seawater and in aerobic sediments. When hydrazine reduced technetium is added to seawater, its oxidation to pertechnetate occurs rapidly and does not follow simple first-order kinetics. In the presence of anaerobic sediments, pertechnetate present in seawater may be immobilized as highly insoluble compounds. Although redox conditions should be responsible for reduction and fixation of technetium, diffusion through the sediment could be a rate limiting factor. Marine biota do not accumulate technetium to a remarkable extent, but in a few species relatively high concentration factors have been observed. Since accumulation kinetics are generally slow, it is difficult to achieve steady- state conditions: the application of mathematical models proved to be useful in reducing the duration of experiments directed to obtain concentration factors.

Additional information

Authors: SCHULTE E H, ENEA, CENTRO RICERCHE ENERGIA AMBIENTE, S. TERESA, LA SPEZIA (ITALY);SCOPPA P, ENEA, CENTRO RICERCHE ENERGIA AMBIENTE, S. TERESA, LA SPEZIA (ITALY);SECONDINI A ENEA, CENTRO RICERCHE ENERGIA AMBIENTE, S. TERESA, LA SPEZIA (ITALY), ENEA, CENTRO RICERCHE ENERGIA AMBIENTE, S. TERESA, LA SPEZIA (ITALY)
Bibliographic Reference: XXIXTH CONGRESS AND PLENARY ASSEMBLY "MARINE RADIOACTIVITY" LUZERN (SWITZERLAND), OCT. 11-19, 1984 WRITE TO CEC LUXEMBOURG, DG XIII/A2, POB 1907 MENTIONING PAPER E 31827 ORA
Availability: Can be ordered online
Record Number: 1989123005000 / Last updated on: 1987-01-01
Category: PUBLICATION
Available languages: en