Heavy Metals in Bottom Sediment in the Upper and Lower Volga

Abstract

Heavy metal concentrations in bottom sediment in some reaches of the Upper (the Ivankovo Reservoir) and Lower Volga (from Volgograd to the mouth offshore area). The bottom sediment in the Ivankovo Reservoir are shown to be heavily polluted by Cu and Zn and to a lesser extent, by Co and Ni; heavy pollution with Ni and Cr and moderate pollution with Zn and Mn were recorded in the Lower Volga. Principal component procedure was used to assess bottom sediment pollution. The role of organic matter in the formation of the Ivankovo Reservoir bottom sediment pollution with heavy metals is shown to be moderate because of the weak correlation between heavy metal concentration and organic matter content of bottom sediment. The same is true for the Lower Volga because of low organic matter content of bottom sediment. The major role in the redox cycle of elements is shown to belong to Fe in the Ivankovo Reservoir and Mn in the Lower Volga.