Abstract
The chemical composition of the bottom sediments of the Volga-Akhtuba floodplain was assessed. Chlorides (36 mg/kg) were found to be one of the predominant anions, while calcium (27 mg/kg) and sodium (27 mg/kg) were the predominant cations. In terms of pH, the bottom sediments were weakly alkaline throughout the studies. The agrochemical composition of bottom sediments of the studied water body corresponded to lime sapropel due to the content of organic matter in them (4.21%), as well as common forms of nitrogen (0.58%), phosphorus (0.27%) and potassium (1.1%). To assess the chemical and toxicological parameters in samples of bottom sediments, the quantitative content of metals and pesticides was determined. It was found that their content does not exceed the maximum permissible concentrations. An analysis of the IR spectrum data made it possible to establish that the IR spectrum contains absorption bands characteristic of bentonite clays, which have good fertilizing and water-retaining properties.