Online ISSN : 1884-4111
Print ISSN : 0033-8303
ISSN-L : 0033-8303
Uptake and Loss of Radioactive Ruthenium by Freshwater Organisms
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1971 Volume 20 Issue 8 Pages 376-382


The uptake of radioactive ruthenium by freshwater organisms in a biocenose was studied in an aquarium ecosystem which consisted of natural river water, duckweeds, mud snails, river snails, freshwater mussels, crucian carps and bottom sands. The aquarium was equipped with a filtration-aeratian apparatus.
After a single addition of 106Ru in nitrosyl ruthenium nitrato complex forms into the aquarium ecosystem, the uptake and distribution of 106Ru in organisms were observed.
The loss of 106Ru from organisms were also studied.
The radioactive concentration in rearing water rapidly decreased in 1 or 2 days and then maintained a constant level. The radioactive concentrations of 106Ru in organisms reached peaks in 1 or 2 days, then gradually decreased with a gradual tendency to reach an equilibrium state. The deposition of 106Ru in upper layer of bottom sands reached an equilibrium state in about 7 days.
The average concentration factors for 106Ru in organisms showed a decreasing tendency in following order: duckweeds, mud snails, river snails, freshwater mussels and crucian carps.
In soft tissues of mud snails, freshwater mussels and river snails, the concentration factors for 106Ru (RuNO-nitrato) were less than about several times in rearing single species.
However, in crucian carps no significant difference of the concentration factor for 106Ru was observed with different rearing conditions.
In crucian carps, about 80% of total radioactivity was distributed in visceral mass including digestive tract.
The loss of 106Ru in chlorocomplex forms from some organisms was more rapid than that of ruthenium in nitrosyl nitrato complex forms. Two biological half-lives of 106Ru were observed in some tissues.

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