FORMS OF SILICON MIGRATION IN WATERS IN THE ZONE OF INFILTRATION EFFECT OF THE CHITA TPP-1 ASH DUMP (THERMODYNAMIC ASSESSMENT)

: As a result of thermodynamic calculations using the HydroGeo 32 program, the possible forms of the presence of dissolved silicon in the waters of the settling tank of the Chita TPP-1 hydraulic ash dump and groundwater in the zone of its influence due to infiltration losses are determined. At Si concentrations of 2.1–17.8 mg/L, of the avail-able forms in the program, (HSi 2 O 6 ) 3 – is predominant, the contents of H 4 SiO 4 and SiO 2 following it are 6–8 orders of magnitude lower. The minimum calculated concentrations ( n 10 –21 mg/L) were obtained for (Si 2 O 5 ) 2 – and (SiO 4 ) 4– ions at pH 7.20.