Adsorption Studies of Radionuclides by Turkish Minerals: A Review

Abstract

Hazardous radionuclides are produced during normal operation of nuclear power plants and research facilities. They can also spread to the environment due to fallout from nuclear accidents and nuclear weapon tests. The removal of hazardous radionuclides and the safe management of radioactive waste are of vital necessity. Natural minerals have been widely used for the removal of heavy metals and radionuclides because of their low cost, high capacity and radiation resistance properties. Turkey has an abundant natural mineral deposits. These deposits include clinoptilolite, bentonite, montmorillonite, kaolinite, vermiculite, illite, red clay, sepiolite, diatomite, perlite and volcanic tuff. Within the scope of this review, Turkish minerals were classified as three main groups as; zeolites, clay minerals and other minerals. The review consists of sections on the general properties of natural minerals such as zeolites and clays, the characteristics of Turkish minerals, and the adsorption performance of these minerals against some radionuclide ions (Sr, Cs, U, Th and Po).

Treatment of Waters Having Different Ionic Composition and pH with Natural Zeolites from Bulgaria

“…This change in pH is supposedly related to the partial dissolution of calcite (1.7% in Golobradovo, Table 2, Figure 3B) from the acidic water and the appearance of HCO 3 − in GBtrn1w. The neutralization of the water leachate marks the complete adsorption of U because, at pH ≥ 5, the U is completely adsorbed as reported by [5,[67][68][69]. Unlike the leachate from Golobradovo, the pH of Beli Plast (BPtrn1w) did not change much and remained acidic (pH = 3.40), which explains why U and the other transition metals (Cu 2+ , Zn 2+ , Cd 2+ , Pb 2+ , Fe 2+ , Co 2+ , and Ni 2+ ) remain in the leachate at a higher content.…”

Removal of Cesium and Strontium Ions from Aqueous Solutions by Thermally Treated Natural Zeolite

“…As estimated from the adsorption and desorption of the two cations with 1 M ammonium acetate solution, chemisorption dominates the retention for the monovalent Cs + and bivalent cation of Sr 2+ , and this can be due to a lesser extent by the zeolite structure. A possible explanation of the higher contribution of chemisorption to the retention of Cs + and Sr 2+ is that the stable inner-sphere complexes are formed at the zeolite surface [37]. The higher ionic radius of Cs + and Sr 2+ compared with the major cations from zeolite The most important changes in IR spectra following the Cs + and Sr 2+ sorption are observed in the range of the pseudo-lattice vibrations, that is, 700-600 cm −1 , as it has been previously reported for other heavy metals sorption [29].…”