Dynamics and migration of microelements-metals in the water-solid suspension system of the Prut River

The article is based on the results of the investigations carried out in the period 2020- 2023 on the microelements-metals (Ag, Al, Ba, Be, Bi, Cd, Co, Cr, Cu, Li, Mn, Mo, Ni, Pb, Sr, Ti, Tl, V, Zn) in the water-solid suspension system in the Prut River downstream the Costești-Stânca reservoir till the confluence with the Danube River. Water samples were filtered in situ through membrane filters with a pore diameter of 45 microns, in order to separate dissolved metals from those in solid suspensions. Inductively coupled plasma atomic emission method was used for the determination of metals, with the assistance of the ICP OES iCAP 6200 Duo spectrometer. In most cases, the lowest concentrations, especially in suspensions, were recorded in the Costești- Stânca – Braniște river section, while the highest - downstream of the confluence of the Jijia River with the Prut River. By applying the ratio of the dissolved and suspended forms of metals in the river runoff as a geochemical criterion, it was revealed that in the last years, in conditions of hydrological droughts, only Al, Mn, Ti, Tl, V, Pb, Co, and Cr predominantly migrated in suspensions in the hydrographic basin of the Prut River.