Modified Sorbents Based on BAU-A Activated Carbon and Coarsely Porous Silica Gel for Removing Radionuclides and Nonferrous Metals from Aqueous Solutions

Abstract

Sorption of radionuclides (⁹⁰Sr, ⁹⁰Y, ¹³⁷Cs, ¹⁵²Eu) and nonferrous metals (Cu, Ni, Zn, Pb) from aqueous solutions onto granulated sorbents based on coarsely porous silica gel of KSKG and MSKG grades and on BAU-A activated carbon was studied. The granulated sorbents based on coarsely porous silica gel of KSKG and MSKG grades, modified with Cu, Zn, and Ni ferrocyanides, efficiently take up ⁹⁰Sr and ⁹⁰Y from distilled water. In tap water, the sorption efficiency for all the sorbents based on KSKG and MSKG does not exceed 70%. The surface of BAU-A was modified by keeping it in a nitrating atmosphere [NO_x-air or HNO₃ (vapor)-air] at 90–110°C for 4 h, and also by impregnating it with 10 wt % triethanolamine (TEA), triethylenediamine (TEDA), or urea (CH₄N₂O). The sorbents based on BAU-A activated carbon efficiently take up ⁹⁰Y (analog of trivalent actinides and lanthanides) and nonferrous metal ions from various aqueous solutions. Modification of BAU-A decreases its sorption capacity for Cu²⁺, Ni²⁺, and Zn²⁺ but increases its sorption capacity for Pb²⁺.