Freshwater plankton as sorbent: Differences in the sorption properties of live and dead plankton

Resumo

The distribution coefficients of a number of chemical elements between live and dead plankton and aquatic medium were determined experimentally. The sorption isotherms of macro- (Mg, Ca) and microelements (Sr, Ba, Mn, Fe, REE, Th, U) on plankton as biosorbent under the conditions when their level exceeds the natural background in water follow the Langmuir equation. The equation parameters for samples of live and dead plankton differ statistically significantly. In the sorption affinity level (logK_d [mL g^–1] ~3–5), freshwater plankton can be considered as effective biosorbent. Electron microscopic examination with local multielement analysis revealed abnormally high content of manganese in the form of adsorption colloid for Trachelomonas acanthostoma var. acanthostoma plankton alga in separate water samples taken from the cooling pond of the Beloyarsk NPP.