Combined effect of heavy metals and shungite on the indicator plankton species

Abstract

The combined effect of salts of heavy metals and shungite on the test organisms of phyto- and zooplankton has been studied. The toxic effect of both cadmium sulfate and potassium dichromate on the culture of Scenedesmus guadricauda was inactivated in the presence of shungite (100 g/L). The efficiency of photosynthesis, the number of cells, the proportion of living cells, and the lifetime of the microalgae cell population increased after adding shungite to the medium (without toxicants). In addition, in acute experiments that lasted up to 96 h, the toxicity of potassium dichromate, copper sulfate, and cadmium sulfate on crustaceans (Daphnia magna and Ceriodaphnia affinis) was studied in the presence of shungite (0.01 g/L) and without it. This study of the effect of shungite’s presence on crustaceans showed that it protected both Daphnia magna and Ceriodaphnia affinis from the action of toxicants at the minimum concentration (0.01 g/L) of the five tested. Daphnia magna died at higher concentrations of shungite. It was shown that the acute toxicity of heavy metals for the two crustacean species decreased in the series Cu–Cd–Cr. The analysis of the obtained data showed that the shungite concentrations necessary for the inactivation of heavy metals were thousands of times higher for algae than for crustaceans. Therefore, when using the shungite as a protector against the toxic effects of various substances, a preliminary laboratory analysis of the survival of different species of hydrobionts in a specific aquatic environment is necessary.