Tag:bottom deposits

№6|2016

ENVIRONMENTAL PROTECTION

bbk 000000

UDC 550.41+556.114

Boldyrev K. A., KUZMIN V. V., KURANOV N. P.

The method of calculating heavy metal release from the layer of water body bottom deposits

Summary

The basics of the method of predicting heavy metal distribution between water and solid phases of bottom deposits in water bodies is outlined. Compared to other models of calculating heavy metal distribution between bottom deposits and void water the developed methodology takes into account the ongoing geochemical processes at the improved level with the use of advanced methods of geochemical modeling. An example of calculating heavy metal distribution under the conditions of the chemical composition of the solution changing with the use of advanced calculation methods in PhreeqC 2.18 program code is presented. The method can be used for the following tasks: geological mapping of the pollution of bottom deposits with heavy metals in water reservoirs and lakes; evaluation of the impact of bottom deposits on the chemical composition of water in water reservoirs and lakes; evaluation of the possible elimination of bottom deposits pollution or their immobilization and other measures of mitigating their impact on the water quality; evaluation of bottom deposits removal during dredging and also for solving the problem of their further utilization; evaluation of the possible instantaneous release of heavy metals from polluted bottom deposits and other emergency situations.

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№3|2017

ENVIRONMENTAL PROTECTION

bbk 000000

UDC 550.424:574

Boldyrev K. A., Utkin S. S., Kazakov S. V.

Specificities of predicting metal distribution between aqueous phase  and bottom sediments  (by the example of strontium and cesium radionuclides)

Summary

The basic provisions of the developed methodological approach to predicting the coefficient of Kd radionuclide distribution on the material of bottom sediments and suspended substances in water bodies are presented. As a tool for predicting Kd coefficient of me­tals under the conditions of the changing chemical composition of water the use of geochemical modelling was suggested. The basic approaches, models and results of predicting the values of Kd coefficient of metals in a reference water body (a surface water reservoir – radioactive waste storage) characterized by high pollution with 90Sr strontium and 137Cs radionuclides as well as by the intensive decrease of water mineralization are laid out. During the research the specific features of hydrochemical and hydrodynamic behavior of metals in the water body system as well as the methods of geochemical modeling were studied in detail. The geochemical thermodynamic model of metal sorption (by the example of 90Sr and 137Сs) by the suspended matter and bottom sediment layer in the model water reservoir was developed that could be considered as a basis for modeling different scenarios of the evolution of real polluted water reservoirs. The values of Kd coefficient for 90Sr and 137Сs at decreasing water mineralization were calculated. It was determined that Kd value is increasing while water mineralization is decreasing. The model can be used for predicting the rate of metal elimination from polluted water bodies in the process of self-purification.

Key words

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