Functionalization of carbon nanomaterials by means of phytic acid for uranium enrichment

Lei Li; Ran Ma; Tao Wen; Pengcheng Gu; Sai Zhang; Maosheng Zheng; Xilin Wu; Xinjia Zhang; Tasawar Hayat; Xiangke Wang

doi:10.1016/j.scitotenv.2019.133697

Functionalization of carbon nanomaterials by means of phytic acid for uranium enrichment

Sci Total Environ. 2019 Dec 1:694:133697. doi: 10.1016/j.scitotenv.2019.133697. Epub 2019 Aug 1.

Authors

Lei Li¹, Ran Ma¹, Tao Wen², Pengcheng Gu¹, Sai Zhang¹, Maosheng Zheng¹, Xilin Wu³, Xinjia Zhang¹, Tasawar Hayat⁴, Xiangke Wang⁵

Affiliations

¹ MOE Key Laboratory of Resources and Environmental Systems Optimization, College of Environmental Science and Engineering, North China Electric Power University, Beijing 102206, PR China.
² MOE Key Laboratory of Resources and Environmental Systems Optimization, College of Environmental Science and Engineering, North China Electric Power University, Beijing 102206, PR China. Electronic address: twen@ncepu.edu.cn.
³ College of Geography and Environmental Science, Zhejiang Normal University, Jinhua 321004, PR China.
⁴ NAAM Research Group, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia.
⁵ MOE Key Laboratory of Resources and Environmental Systems Optimization, College of Environmental Science and Engineering, North China Electric Power University, Beijing 102206, PR China; Hebei Key Lab of Power Plant Flue Gas Multi-Pollutants Control, Department of Environmental Science and Engineering, North China Electric Power University, Baoding 071003, PR China.

PMID: 31401514
DOI: 10.1016/j.scitotenv.2019.133697

Abstract

A promising strategy for radionuclides immobilization on the functionalized carbon-based materials is a pursuing issue. Here, we developed phosphorylated hydrothermal carbon spheres (HCSs@PO₄) through chemical-grafted method using phytic acid as a phosphorus source. When served as U(VI) scavenger from simulated environmental wastewater, the resulting HCSs@PO₄ showed excellent adsorption capacity toward U(VI) (552.49 mg·g^-1 at pH 5.0 and T = 298 K), outperforming that of HCSs (32.06 mg·g^-1) and state-of the-art materials. A weak ionic strength-dependence of U(VI) enrichment with HCSs@PO₄ was investigated by a series of pH experiments, indicating an inner-sphere surface complexation. Through thermodynamic study, high temperature promoted the adsorptive ability of HCSs@PO₄ toward U(VI), revealing the endothermic and spontaneous nature. Additional selective adsorption applications were conducted to evaluate the ability of HCSs@PO₄ to capture uranium fission byproducts and other radioactive ions. Analyses of characteristic means (FT-IR and XPS) revealed enhanced uptake performance of HCSs@PO₄ originated from grafting abundant phosphate groups, which exhibited the stronger surface complexation toward U(VI) than sluggish hydroxyl and carboxyl groups. The findings herein highlighted a facile and powerful technique for the manufacture of phosphorylated carbon-based materials of radioactive wastewater remediation.

Keywords: Adsorption; Hydrothermal carbon spheres; Phosphate groups; U(VI).