"One-can" strategy for the synthesis of hydrothermal biochar modified with phosphate groups and efficient removal of uranium(VI)

Xinchen Chen; Yang Wang; Hongtao Xia; Qi Ren; Yang Li; Lejin Xu; Chuting Xie; Yun Wang

doi:10.1016/j.jenvrad.2023.107182

"One-can" strategy for the synthesis of hydrothermal biochar modified with phosphate groups and efficient removal of uranium(VI)

J Environ Radioact. 2023 Jul:263:107182. doi: 10.1016/j.jenvrad.2023.107182. Epub 2023 Apr 23.

Authors

Xinchen Chen¹, Yang Wang¹, Hongtao Xia¹, Qi Ren¹, Yang Li¹, Lejin Xu², Chuting Xie³, Yun Wang⁴

Affiliations

¹ School of Nuclear Science and Engineering, East China University of Technology, Nanchang, 330013, Jiangxi, China.
² School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan, 430074, Hubei, China.
³ School of Architecture & Urban Planning, Huazhong University of Science and Technology, Wuhan, 430074, Hubei, China.
⁴ School of Nuclear Science and Engineering, East China University of Technology, Nanchang, 330013, Jiangxi, China. Electronic address: wangyun@ecut.edu.cn.

PMID: 37094506
DOI: 10.1016/j.jenvrad.2023.107182

Abstract

Significant selectivity, reasonable surface modification and increased structural porosity were three key factors to improve the competitiveness of biochar in the adsorption field. In this study, a hydrothermal bamboo-derived biochar modified with phosphate groups (HPBC) was synthesized using "one-can" strategy. BET showed that this method could effectively increase the specific surface area (137.32 m² g^-1) and simulation of wastewater experiments indicated HPBC had an excellent selectivity for U(VI) (70.35%), which was conducive to removal of U(VI) in real and complex environments. The accurate matchings of pseudo-second-order kinetic model, thermodynamic model and Langmuir isotherm showed that at 298 K, pH = 4.0, the adsorption process dominated by chemical complexation and monolayer adsorption was spontaneous, endothermic and disordered. Saturated adsorption capacity of HPBC could reach 781.02 mg g^-1 within 2 h. The introduction of phosphoric acid and citric acid by "one-can" method not only provided abundant -PO₄ to assist adsorption, but also activated oxygen-containing groups on the surface of the bamboo matrix. Results showed that adsorption mechanism of U(VI) by HPBC included electrostatic action and chemical complexation involving P-O, PO and ample oxygen-containing functional groups. Therefore, HPBC with high phosphorus content, outstanding adsorption performance, excellent regeneration, remarkable selectivity and green value provided a novel solution for the field of radioactive wastewater treatment.

Keywords: Adsorption; Bamboo; Biochar; Phosphate groups; Uranium(VI).

MeSH terms

Adsorption
Charcoal / chemistry
Hydrothermal Vents
Kinetics
Phosphates*
Radiation Monitoring
Uranium*
Water Pollutants, Chemical* / analysis

Substances

biochar
Charcoal
Phosphates
Uranium
Water Pollutants, Chemical