Physical and chemical substantiation of decontamination of the 5th district of Vasilievsky Island in St. Petersburg from strontium-90 contamination
- 1 — G.V. Plekhanov Saint Petersburg Mining University
- 2 — G.V. Plekhanov Saint Petersburg Mining University
- 3 — G.V. Plekhanov Saint Petersburg Mining University
- 4 — G.V. Plekhanov Saint Petersburg Mining University
Abstract
In order to calculate parameters of purification of soils from 90 Sr the exchange isotherm of Sr 2+ Ha cations of iron (III) between Cambrian clay and aqueous solution with pH = 3 was studied. Isotherms of joint cation adsorption in joint presence are described by the Langmuir equation. Using the values of the Langmuir constants, the Gibbs constant and energy of ion exchange equal to 15 and -6.7 kJ/mol, respectively, were calculated. These values coincide with those calculated from the individual adsorption isotherms of Sr 2+ and Fe (III) cations on clay. According to the obtained constants it is possible to deactivate soils from 90 Sr contamination by means of ion-exchange washing with solutions of iron (III) salts, which is confirmed by field studies in the 5th quarter of Vasilievsky Island. The performed technical-economic assessment of the decontamination of the 5th quarter shows that the washing cleaning will give an economic effect of about 150 million rubles compared to soil removal and burial.