Magnetite-containing сomposite based on corn cob cellulose for adsorption of U(VI) compounds

Abstract

Sources of U(VI) compounds in ground and surface water are uranium-containing minerals and anthropogenic activity: nuclear and thermal power plants, mineral processing plants, mines, testing nuclear weapon. Due to toxicity and radioactivity of the compounds of this metal, their content in water is strictly regulated. In order to remove small amount of U(VI) from water, adsorption and ion exchange look most attractively. In this work, magnetite-containing composite adsorbent based on cellulose, which was produced from corn cobs, has been developed. Its advantages over synthetic adsorbents are cheap and available feedstock as well as a simple manufacture procedure. In order to provide high magnetite content (» 13.5 mass. %), both hydrophilic and hydrophobic constituents were removed from cellulose before the particle embedding. Mesopores, a size of which are 10 nm, make a contribution to porous structure of the composite and magnetite, pure cellulose is characterized by microporous structure. Comparing with this material, the composite shows a wider pH interval of U(VI) adsorption. The most favorable conditions are realized at pH 4–6, when the degree of uranium removal reaches 87–97 %. The composite shows a synergetic effect demonstrating the fastest adsorption than both magnetite and cellulose. Moreover, higher capacity of adsorption monolayer was found for the composite (0.71 mmol g–1) comparing with magnetite (0.14 mmol g–1). For utilization, the adsorbent can be added to uranium-containing ore before its treatment.