Fabrication of electrospun cellulose/ball-milled bone char membranes for fast, efficient and selective sorption of aquatic U(VI)

Powdered sorbents in aqueous solutions suffer from the deficiency in the solid/liquid separation even the sorption capacities were higher than their bulk or less-dispersed forms. The combination of powdered sorbents with membranes would be highly desired to balance the contradiction between high separation efficiency and sorption capability. In this study, cellulose/ball-milled bone char (CL/MB) membranes with sub-micrometer diameter (276.0–281.7 nm) and developed porosity (21.5–98.6 m 2 /g) were fabricated by electrospinning technique. Bone chars originated from the pyrolysis of bone residuals at 350 °C, 500 °C and 650 °C could well dispersed in the electrospinning solvent. CL/MB membranes could adsorb U(VI) with fast kinetics (180.0 min), efficient capacity (309.8 mg/g at pH 5.00 and T 298 K) and excellent selectivity against the interference of coexisting ions in simulated waters. With spectroscopic analysis , the formation of (Ca(UO 2 ) 2 (PO 4 ) 2 (H 2 O) 3 precipitation was dominant for the selectivity. The surface complexation of O-/reductive N-groups with U(VI), the electrostatic attraction of deprotonated O - with positively charged U(VI) species, the cation exchange of U(VI) with Ca 2+ components, and the cation-π coordination of U(VI) should also be considered. This study pave the way for the feasible utilization of electrospun CL/MB membranes as a promising sorbent to capture aquatic U(VI).