Effective Sequestering of Cobalt, Copper and Nickel Using Ethylenediaminetetraacetic Acid Modified Mesoporous Silica

Abstract

Ethylenediaminetetraacetic acid functionalized mesoporous silica (EDTA-SBA-15) has been synthesized for effective sequestering of corrosion products from nuclear power reactor coolant. Mesoporous structure, long-range-order, and functional group loading were evaluated by N2 adsorption/desorption, small-angle X-ray scattering (SAXS), high resolution transmission electron microscopy (HRTEM) and Fourier transform infrared spectroscopy (FTIR) techniques. Results showed a proportional relationship between functional group loading and adsorption capacity. Adsorption strictly followed pseudo second order reaction and removed the corrosion metals rapidly within 20 minutes. The adsorption capacity, calculated on the basis of Langmuir model, was 1.33 mmol/g, 1.44 mmol/g, and 1.40 mmol/g for Co(II), Ni(II) and Cu(II) respectively; which is higher than other EDTA based adsorbents. Moreover, EDTA-SBA-15 revealed excellent stability against gamma irradiation, and in concentrated acidic media, which makes it practicable to apply for radioactive decontamination in nuclear facilities.