Investigations on the behaviour of some radioisotopes in a laboratory-scale aquatic ecosystem

Mineralogical analysis and sorption characteristics of Ismailia Canal bottom sediments were investigated. The behaviour of the isotopes 89Sr, 134Cs, 60Co and 65Zn when injected into a laboratory-scale aquatic ecosystem was studied. In the case of impounded ecosystems a two-phase relation describing the behaviour of the isotope in the system was obtained. For flowing ecosystems a three-phase relation was demonstrated. The degree of penetration of the investigated isotopes into the bottom sediment layers of the aquaria was recorded in the form of respective histograms for flowing and non-flowing systems. The data obtained for both systems allow for the calculation of the number of displacements, or, in other words, the volume of contaminated water that can be injected into a laboratory-scale ecosystem before a given concentration ratio is exceeded. (author)