Fabrication of fungus/attapulgite composites and their removal of U(VI) from aqueous solution

A new adsorbent of fungus/attapulgite (F/ATP) composites was synthesized by one-pot hydrothermal carbonization method under mild conditions and characterized by scanning electron microscope, X-ray diffraction, thermogravimetric analysis and Fourier transform infrared spectroscopy. The characterized results showed that the fungus (Geotrichum sp. dwc-1) can be as a superior template for the assembly of nanoscale attapulgite by covalent bonding. According to batch experiments, the maximum sorption capacity of F/ATP for U(VI) was 125 mg/g at pH 4.0 and T = 303 K. The thermodynamic parameters calculated from sorption isotherms showed that U(VI) sorption on F/ATP was a spontaneous and endothermic process. The fixed-bed column experiment further demonstrated that F/ATP presented the excellent adsorption performance. It was determined from regeneration experiments that the F/ATP composites exhibited high sorption of U(VI) (similar to 91%) over six cycles. Therefore, F/ATP can be as a promising candidate for the removal of U(VI) from aqueous solution due to its low-cost, sustainable, and efficient feature. (C) 2015 Elsevier B.V. All rights reserved.