DBPapers
DOI: 10.5593/sgem2017/31/S12.014

CHEMICAL MODELLING OF MAJOR AND TRACE ELEMENTS MIGRATION COMPLEXES IN WESTERN MONGOLIAN SALINE LAKES

M. Kolpakova, O. Gaskova
Monday 11 September 2017 by Libadmin2017

References: 17th International Multidisciplinary Scientific GeoConference SGEM 2017, www.sgem.org, SGEM2017 Conference Proceedings, ISBN 978-619-7408-04-1 / ISSN 1314-2704, 29 June - 5 July, 2017, Vol. 17, Issue 31, 105-112 pp, DOI: 10.5593/sgem2017/31/S12.014

ABSTRACT

The inorganic migration forms of trace elements in the lakes of Western Mongolia characterized by a high content of such trace elements as U (up to 3 mg/L), Li (up to 82), Br (up to 718), Al (up to 0.4) were calculated using HydroGeo software (Bukaty, 2002). All studied lakes have high concentration of total dissolved salinity (TDS) that ranges from 1 to 360 g/L and high pH values varies from 6.9 to 10.3. According to calculated results Br, Li, Rb, Na, K, Sr, Ca, and Mg in lake waters migrate predominantly in ionic forms. The last two cations (Ca and Mg) are also characterized by a partial (up to 40%) binding to complexes with carbonate, sulfate and chloride ions, depending on the salinity and acid-base conditions of the environment. The fluoride can be bound in MgF⁺ form (up to 30%). The predominant forms of migration for Si, V (V), and As(V) are HkMeOnᵐ⁺, for Al is usually the form of hydroxocomplexes. The uranium (VI) migrates in carbonate complexes of different stoichiometry. The influence of the geochemical environment on the mobility of elements and the equilibrium state of water with minerals presenting in bottom sediments and in the catchment area of lakes is assessed. It is shown that at different stages of the lakes evolution, the variety of secondary mineral phase composition is controlled, on the one hand, by the migration features of the chemical elements, and, on the other hand, by the degree of water evaporation that determining a selective concentration of elements in a solution up to industrially valuable values.

Keywords: Mongolia; trace elements; migration species; HydroGeo