Scores:
12
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120.9
ICV
 
 

PROBLEMS OF PROTECTION OF URBAN AREAS FROM RADIONUCLIDES STRONTIUM-90 AND CAESIUM-137 AFTER TECHNOLOGICAL DISASTERS

Olga Cheremisina 1  ,  
Vasiliy Sergeev 1  ,  
Alexander Fedorov 1  ,  
 
1
Department of General and Physical Chemistry, Saint-Petersburg Mining University, 21st Line 2, 199106 Saint Petersburg, Russia
J. Ecol. Eng. 2017; 18(3):97–103
Publish date: 2017-05-02
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ABSTRACT:
The methods of decontamination of radionuclides from soils are considered. The literature focuses on fixing radionuclides in soils and creating geochemical barriers that it is prevent the spread of pollution. The main disadvantage of these methods is exclude the possibility of building a territory. It is need to clean up the area to the sanitary and hygienic requirements for further use and then it is desirable to fix the residual activity. Carried out an analysis of forms of radionuclides fixation in soils and mechanics of this fixation, therewith revealed that Cs-137 fixed more strongly on mineral component of soil, than Sr-90, which is mainly in the acid-soluble and exchangeable form, and, as a consequence, passes into the liquid phase during soil deactivation more easily. Contaminated soil deactivation in the urbanized territory is possible by washing it by ferric chloride solution at a concentration 0.02-0.05 M and with an equimolar addition of an ammonium chloride. Therewith most efficient methods, which used in-situ conditions, are heap and convection leaching technologies with treatment degree, which not less than 80%. At the same time, the most efficient methods which used in-situ conditions are heap and the convection leaching. The hardware-technological scheme of a convection leaching is presented. Noted that ammonium salts additions slightly rising coefficient of treatment from Sr-90. Because ammonium salts aren’t expensive, their additions allow to obtain significant economic benefits due to decreasing of ferric chloride consumption, which is more valuable, and waste water volume reduction.
CORRESPONDING AUTHOR:
Vasiliy Sergeev   
Department of General and Physical Chemistry, Saint-Petersburg Mining University, 21st Line 2, 199106 Saint Petersburg, Russia
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