The Composition and Element's Speciation in the Spring Waters of the Southern Part of the Balashikha Urban District (Moscow Region)

Data are presented on the contents of major ions (Ca2+, Mg2+, Na+, K+, N, Cl-, SO42-, HCO3- and NO3-) along with dissolved trace elements (Sr, Ba, Fe, Mn, Co, Ni, Cu, Zn, Cd, Pb, Al, Ti, Rb, U, V, Cr, As, Se, Mo, and Ag) in the waters of 12 springs in Balashikh. urban district of Moscow Region. In view of the testing data for the springs, the composition of groundwaters in different water-bearing layers was characterized for the Ucha-Balashikha hydrogeologic block, which is associated with the western part of the Meshchera hydrogeologic region of the Moscow artesian basin. The waters were found to be of low-acid to nearneutral (pH 5.3-6.9), of 130-670 mg/L mineralization and are characterized by wide variety of their major component compositions, as well as by mainly increased concentrations of nitrate and ammonium ions. It was shown that the average contents of trace elements was characteristic in general for groundwaters in the leaching zone of the temperate climate. TLVs were not exceeded, excluding Fe and Mn, in waters of several springs. Based on thermodynamic calculations using Visual-MINTEQ software, it was found that the predominant dissolved forms in the waters of the surveyed springs were free ions for Ba, Sr, Fe, Mn, Zn, Cd, Ni, and Co, and carbonate or organic complexes for Cu and Pb.