ISSN:
1573-5117
Keywords:
mesocosm
;
sediment
;
trace element
;
radionuclide
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Radiotracers injected as soluble salts into ≈1.2 m3 limnocorrals in a shallow dystrophic lake were transported rapidly (2 to 12% d−1) from the water to the bottom sediments. Removal rates of most contaminants declined after ≈14 days. Tracers were removed from the water much more rapidly than stable element analogs present naturally. After 3 weeks Am, Co, Ra, Hg, Sn and Fe activities on the enclosure walls were greater than 15% of the activity in the water. However, activity on the walls was a small fraction (〈 6%) of the total amount of tracer injected. Particle fluxes inside the corrals were lower and much less variable than those measured outside. This difference appears to result from greater resuspension of bottom sediments in the lake than in the enclosures. Both particle-bound and soluble tracers were measured in cores of bottom sediments. Tracer sorption onto particles, diffusion into the bottom sediments, and uptake on the plastic enclosure walls were rapid and reversible. Tracer kinetics were very reproducible in replicate enclosures, providing a simple, experimental system in which limnological conditions can be manipulated. Loss rates and distributions of stable isotopes and radioisotopes can be used to develop and test a general model of element transport applicable to both short and long term analyses.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00008237
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