Salt Systems And Natural Resources

The activities of the Laboratory “SALT SYSTEMS AND NATURAL RESOURCES" (SSNR) at IGIC – BAS are focused on fundamental and applied research in the fields of inorganic material science and preservation and utilization of natural resources.

• Inorganic material science

The research in this field is targeted in two directions:

– chemistry of water-salt systems;

– synthesis and characterization of calcium phosphate biomaterials.

Chemistry of water-salt systems. Theoretical and experimental studies are carried out on the processes of dissolution and crystallization in water-salt two-, three- and multicomponent systems. Crystallization and co-crystallization processes of simple and double salts, as well as of mixed crystals are being investigated. The kinetics of the processes is studied. Stable and metastable phase equilibria are thermodynamically modeled. The regularities between the composition and structure of the solutions and the structure and type of crystallizing solids are established. Interactions taking place in systems under changing conditions are predicted and clarified.

Synthesis and characterization of calcium phosphate biomaterials. Studies on the synthesis and characterization of biomedical materials, including nano- and modified calcium-phosphate composites, are being carried out. Modern instrumental and computational methods are applied to the investigation of the relationship composition-structure-property. Technologies for the production of biomaterials (mainly for dental medicine) with modified chemical and improved physical characteristics and biological activity are being developed.

• Preservation and utilization of natural resources

The research is focused on two directions:

– environmental studies;

– sustainable use.

Environmental studies aim at evaluating, predicting and improving the ecological status of industrially polluted natural waters, soils and vegetation by applying various analytical methods and thermodynamic models. Field and laboratory studies are being conducted to determine the degree of contamination, mobility and phytoaccumulation of transition metals. Various thermodynamic models (ionic association model, ionic interaction model and Stockholm- Humic model) are being applied to determine the inorganic and organic chemical species and dynamics of transition metals in the water – soil – soil extract – vegetation ecosystem.

Sustainable use. Natural mineral raw materials are being used to develop alternative biologically active materials containing biogenic trace elements and their compounds that affect the nervous, antioxidant and immune systems or regulate the mineral dysbalance in the body. Priority use is made of the mineral resources of the Black Sea. Product technologies for medical cosmetics and pharmaceutical industry are being developed. Small-scale production is organized.

1) Rabadjieva, A. Kovacheva, S. Tepavitcharova, M. Dassenakis, S. Karavoltsos
 Trace metal pollution of waters and soils in Kardjali region, Bulgaria,
Еnviron Мonit Аssess , 190(7) (2018) 383-399,

2) Tepavitcharova, S., Havlíček, D., Matulková, I., Rabadjieva, D., Balarew, C., Gergulova, R., Němec, I., Císařová, I., Plocek, J.
Solid phases in the systems glycine–ZnX₂–H₂O (X = Cl−, Br−, I−) at 25 °C,
Monatshefte fur Chemie, 149 (2) (2018) 299-311.

3) Balarew, C., Tepavitcharova, S., Kamburov, S.,
Study of the spontaneous crystallization of Na₂SO₄7H₂O and Na₂SeO₄•7.5H₂O.
Monatshefte für Chemie, 149 (2018) 289-298.

4) Sezanova, K., Kovacheva, D., Rabadjieva, D., Gergulova, R..
Mg- and Zn-modified calcium phosphate fine powders examined by Rietveld refinement. Bulgarian Chemical Communications, 50, Special Issue: F (2018) 99-106.

5) Kamburov, S., Schmidt, H., Voigt, W., Balarew, C.,
Crystal structures of sodium magnesium selenite decahydrate, Na₂Mg(SeO₄)₂10H₂O, a new selenate salt, and sodium magnesium selenate dihydrate, Na₂Mg(SeO₄)₂•2H₂O.
Acta Cryst. C, 73 (2017) 582-587.

6) Rabadjieva, D., Tepavitcharova, S., Sezanova, K., Gergulova, R.,
Chemical Equilibria Modeling of Calcium Phosphate Precipitation and Transformation in Simulated Physiological Solutions,
J Solution Chem 45 (2016) 1620–1633

7) Tepavitcharova, D. Havlícek, I. Matulkova, D. Rabadjieva, R. Gergulova, J. Plocek, I. Nemec, I. Císarova,
New zinc-glycine-iodide complexes as a product of equilibrium and non-equilibrium crystallization in the Gly – ZnI₂ – H₂O system,
Journal of Molecular Structure 1120 (2016) 42-49.

8) Balarew, Ch., Tepavitcharova, S., Rabadjieva, D., Kamburov, S.,
On the crystallization kinetics of highly soluble salts,
Pure and Applied Chemistry, 87(5) (2015) 445-451.

9) Kovacheva, D. Rabadjieva, St. Tepavitcharova,
Simulation of stable and metastable sea-type carbonate systems for optimization of MgCO₃.3H₂O precipitation from waste sea brines,
Desalination, 348 (2014) 66–73

10) Tepavitcharova, S., Rabadjieva, D., Todorov, , Kovacheva, A., Dassenakis, M., Paraskevopoulou, V.
Chemical speciation in fresh, saline and hyper-saline waters,
Pure and Applied Chemistry, 86 (7) (2014) 1097-1104.

• Department of Inorganic Chemistry, Faculty of Science, Charles University, Czech Republic
• Institute of Inorganic Chemistry of the ASCR, Czech Republic
• Department of Chemistry, Laboratory of Environmental Chemistry, National and Kapodistrian University of Athens, Greece