Dying out of the helophytes as the factor of migration of 137Cs in water bodies

Abstract

Quantitative parameters of migration of 137Cs to the bottom sediments of eutrophic (Kyiv reservoir) and oligotrophic (Lake Beloe) water bodies after the dying out of Phragmites australis, Tуpha angustifolia, Glyceria maxima and Scirpus lacustris were determined. The specific activity of 137Cs in the overground organs and plant rhizomes was 8 - 522 Bq/kg, in soil roots – 139 - 3410 Bq/kg. After the dying out of the plants, 1.6 - 8.7 % of the total 137Cs accumulated in the phytomass enters the water masses, 4.9 - 19.7 % enters the detritus, and 63.5 - 83.9 % enters the bottom sediments. In shallow water areas of the studied water bodies as a result of the dying out of helophytes, from 0.3 to 1.1 % of 137Cs of its total number in the upper 30 cm layer of bottom sediments are annually transferred to bottom sediments.

Keywords

• water bodies
• helophytes
• 137Cs migration
• bottom sediments.