Seasonal Variations in the Forms of Heavy Metal Occurrence in the Kuibyshev Reservoir Waters and Bottom Deposits

Seasonal dynamics of total concentrations and the main forms of occurrence of heavy metals (HM) in the water mass and bottom deposits (BD) are studied in the Priplotinnyi (Near-dam) Pool of the Kuibyshev Reservoir. In the near-bottom and interstitial waters, heavy metals are mostly found in the form of complex compounds with organic and mineral ligands; the proportions of these complexes and the dominant form in the above media change from season to season. The hard skeleton of bottom deposits contains a large store of heavy metals that can be a source of the secondary pollution of water masses.