Комбинированное действие фенольных соединений и меди (II) на Elodea canadensis

Abstract

The combined effect of Cu2+ ions and dihydric phenols, hydroquinone and resorcinol, on the yield of electrolytes from shoots of Elodea canadensis was studied. The individual effects of these groups of toxicants on aquatic plants have been fairly well studied. However, their combined action remains a poorly studied issue. This led to increased interest in this topic and the relevance of the research. The test response of E. canadensis during the biotesting of polyphenols, copper, and their mixtures was the release of electrolytes from shoots. This parameter was recorded by the change in the electrical conductivity of the water in which the plant pretreated with the toxicant was placed. The toxicity of solutions of copper, polyphenols, and “copper+polyphenol” mixtures was evaluated in acute experiments: the contact time of E. canadensis shoots with the toxicant was 30 min. The experiments showed that copper (II) caused an increase in the release of electrolytes from the shoots of E. canadensis compared to the control (plants not exposed to the toxicant) in the concentration range from 0.001 to 0.0001 N. Thus, the electrical conductivity of a medium containing elodea preliminarily treated with copper (II) at a concentration of 0.0001 N increased to 35 µS after 60 min of exposure. At a content of 0.001 to 0.01 N, the index increased to 62-79 μS. At the same time, in the control, this indicator fluctuated at the level of 2.5-5.5 μS throughout the experiment. Hydroquinone caused a significant increase in the yield of electrolytes from the shoots of E. canadensis at a content of 5ꞏ10-2 M. In this case, the electrical conductivity of the medium in which the elodea treated with polyphenol was placed was 2.5 times higher than in the control (i.e. plant not exposed to toxicants). Resorcinol had a similar effect on E. canadensis at a content of 1ꞏ10 - 1 M) observed a decrease in copper toxicity under the influence of polyphenols. When biotesting mixtures of copper (II) (0.001 N, 0.0001 N) with the studied polyphenols (hydroquinone 5ꞏ10-2 M, resorcinol 1ꞏ10-1 M), a decrease in the toxicity of copper under the influence of polyphenols was observed. The considered method for assessing the toxicity of substances is suitable not only for assessing the individual effects of various pollutants, but also for identifying the combined effects of various compounds. At the same time, the technique is characterized by ease of implementation and high speed of obtaining a response (about 2 hours).