Nitrogen compounds in the surface and subsurface waters of Karelia

Materials of long-term studies of the concentration and distribution of N forms (NH₄⁺, NO₃⁻, NO₂⁻, N_org) in precipitation, surface water and groundwater are generalized. Precipitation was found to be the main source of N compounds input into these waters. The effect of anthropogenic factors is local and does not influence the concentration and distribution of N forms in most water bodies that serve as wastewater recipients. The N forms dominating in precipitation are NO₃⁻ and N H₄⁺; N_org dominates in most surface water bodies, and NO₃⁻ dominates in groundwater. The median concentrations of N_tot in clear surface and subsurface waters are similar. The obtained characteristics of the concentrations and distribution of N forms in natural waters of Karelia can be used for other water bodies in the humid zone.     

Assessing External Water Exchange of Lake Bays by Water Chemistry Characteristics

Water Resources - External water exchange of bays of the lakes Onega (Kondopoga and Petrozavodsk bays) and Ladoga (Hiidenselkä Bay), considering the exchange with the lake water, was assessed...     

One river,two streams: chemical and chromium isotopic features of the Neglinka River (Karelia,northwest Russia)

The physico-chemical and hydrochemical characteristics of run-off of the Neglinka River Basin (northwest Russia) monitored for a year are different for the upstream and downstream sections. The river known hydrologically as the Neglinka, consists hydrochemically of two different streams: one represented by the upstream part of the basin, and the other one by the downstream. The upstream water is characterized by low mineralization (water hardness 0.08–0.43 mmol L^?1) and low δ⁵³Cr values (+0.30 to +0.42‰), whereas the lower part is characterized by high mineralization (water hardness 0.37–3.46 mmol L^?1) and high δ⁵³Cr values (+0.92 to +1.73‰). The difference in chemical composition of the upstream and downstream waters could be due to the underground discharge input. Aqueous chromium (Cr) mobilized from weathering profiles may have been reduced from soluble Cr(VI) to insoluble Cr(III) during the riverine transportation. Partial removal of Cr from the water balance resulted in a decrease in Cr concentration and an increase in δ⁵³Cr values.