Composition and element’s speciation in the spring’s waters of the southern part of Balashikh urban district (Moscow region)

Abstract

This study was carried out to evaluate the content of major ions (Ca2+, Mg2+, Na+, K+, NН4+, Cl–, SO42–, НСO3–, NO3–) and trace elements (Sr, Ba, Fe, Mn, Co, Ni, Cu, Zn, Cd, Pb, Al, Ti, Rb, U, V, Cr, As, Se, Mo, Ag) in the waters of 12 springs in the of Balashikhа urban district of the Moscow region. The district is located within the Uchinsko-Balashikha hydrogeological block, confined to the western part of the Meshchersky hydrogeological region of the Moscow artesian basin. The macro- and micro-component composition of groundwater of various aquifers was characterized according to the sampling data of springs. It has been established that the waters are slightly acidic— near neutral (pH 5,3–6,9), with a mineralization of 130–670 mg/l. Water has highly variations in macrocomponent composition and predominantly high content of nitrate ion and ammonium ion. It is shown that the mean contents of trace elements in the waters of springs are at the level of concentrations characteristic of groundwater in the leaching zone of a temperate climate. Based on the thermodynamic calculation using the Visual-MINTEQ, it was found that the predominant dissolved forms of Ba, Sr, Fe, Mn, Zn, Cd, Ni, Co in the waters of the surveyed springs are free ions, and Cu and Pb are carbonate and organic complexes.