The dynamics of the content and migration of trace metals in aquatic ecosystems of Moldova

Abstract

The current complex investigations, carried out according to well-established methods, allowed us to find the main patterns of the dynamics and migration of metals in the Dniester and Prut rivers, affected by natural and anthropogenic factors. Using a polyfactorial analysis approach, the quantitative effect of main factors (water debit, amount of suspended matter, volume of discharged wastewaters, amount of pesticides and fertilizers metals in water, suspended matter, silt sediments of rivers and reservoirs was revealed. The discharged industrial wastewaters contribute to freshwater pollution with Ni, Zn, Cu, and Cd (r >0.75) The use of fertilizers and pesticides for agricultural purposes affects directly the dynamics of Cu, Zn (r = 0.74-0.92), and the pollution is intensified by the dismembered relief, the peculiarities of rainfall and intensive erosion processes. The Moldavian Thermal Power Plant polluted the water of cooling reservoir with V, Mo, Ni, Cd and the water sediments - also with Pb, Zn and Cu, whose concentrations depend directly on the amount of burned fuel (r=0,76-0,97).