Development of an electrolysis system for tritium enrichment in superficial water samples.
Tritium present in the environment gradually decreased in the last decades and nowadays it has reached extremely low activity concentrations. The purpose of the present work is the implementation of a tritium enrichment system in water samples using electrolytic techniques and pure nickel and iron electrodes. In the present work a mean tritium enrichment factor of 13.0 +/- 3.2 was obtained. This result should allow to reach a minimum detectable activity of tritium in water samples of about 1 tritium unit (TU) or less. The present enrichment system necessitates further adjustments and improvements, such as a cooling system in order to reduce the tritium losses due to evaporation.
Monitoraggio dell'inquinamento da discariche: metodi isotopici per individuare la presenza di contaminazione delle acque sotterranee
The presence of dumps in Italy has been constituting for years a great environmental problem. Numerous they have been the approaches and the methods to study the behaviour of the dumps, and to determine if there can be losses in action from the side or bottom barriers. In this note we introduce some theoretical aspects with regard to the use of isotopic methods to determine possible spillages of leachate from landfills. Such methods are based on the perfect knowledge of the hydrogeological settings which the isotopic contents of deuterium, oxygen-18 and tritium furnish, and on the observation of possible variations of such parameters in comparison to the background environment for the area in examination. Particularly it has been in relief in numerous studies, and in different experiences currently conducted in field by the authors in the last years, as the tritium content of the leachate is superior hundreds of times to that present in the natural waters. This fact implicates the possibility to exploit the tritium as tracing of dump pollution, being the same dump the only possible source of tritium superior to the environmental levels. The use of such isotope as tracing is more useful in comparison to the observation of the chemical data of the waters, since tritium is not influenced by chemical or physical reactions, it belongs to the molecule of the water and it follows the flow of water without suffering decelerations or absorptions of relief. In many cases the variation of isotopic contents is manifested with notable advance in comparison to the arrival of the polluting plume, i.e. the zone of underground water where the chemical parameters have sensitively altered in comparison to the background environment. During the present note are introduced therefore the results of different jobs related to dumps located in the Northern Italy. Key terms: tritium, isotopic techniques, leachate, groundwater, tracers, pollution, landfill. Termini chiave: tritio, tecniche isotopiche, percolato, acque sotterranee, traccianti, inquinamento, discarica.
DESIGN AND PERFORMANCE OF TRITIUM MEASUREMENT SYSTEMS USING ELECTROLYTIC ENRICHMENT.
Abstract Equations and data are given which enable the enrichment, reproducibility, electrical characteristics and heat output of electrolytic tritium enrichment cells to be calculated. From these equations together with the characteristics of the counting method the overall performance of a tritium counting system may be estimated. Two theoretical system designs using liquid scintillation emulsion counting are given. One uses an initial sample volume of 3 l and measures 1 T.U. to ±10% with a throughput of 40 samples per week. The other uses a sample volume of 0.5 l and measures 5 T.U. to ± 10% at the same throughput.