MODERN TECHNIQUES FOR CONTAMINATED SITES REMEDIATION

Remediation of radionuclide contaminated sites requires a combined technique for immobilizing and removal of radioactive matters captured by topsoil. To this end, new immobilizing agents based on interpolyelectrolyte complexes (IPEC) have been developed by joint efforts of VNIINM and MSU. The IPEC treatment produces a water-insoluble but air- and moisture- permeable protective coat, which is resistant to water and wind erosion. The water erosion resistance has been tested under field conditions. The polymeric agents are found to aggregate the soil structure and to increase the water resistance by 3-10 times. For wind erosion tests a laboratory wind tunnel was used. The erosion intensity and limiting air velocity studies with and without the protective coat show that in the wind velocity range from 0 to 40 m/s the treatment with 1.0 l/m 2 of the aqueous solution containing 2% wt. of IPEC provides a dust suppression factor of 10 - 7.5 *10 6 as a function of the treatment technique. The effect of the soil composition and properties on the soil-radionuclide interaction, the contamination features and factors influencing the radioactivity distribution throughout phases and fractions have been studied. Polymer structureformers were experimentally tested using the confinement technique developed. IPEC with trade mark “MM-1” was used at the Chernobyl NPP site in 1986-1990 on a commercial scale. Also, polymers developed can be helpful in reducing highly-saline sand transfer from dried-up bottom of the area of the Aral See ecological calamity. Tests carried out under the Polyarny Ural since 1995 suggest that the polymers are useful for remediation of forest-tundra soils.