Pectin/Al2O3–ZrO2 core/shell bead sorbent for fluoride removal from aqueous solution

Abstract

A novel sorbent of pectin/Al₂O₃–ZrO₂ core/shell beads for fluoride removal was prepared via a coaxial electrostatic spinning device, and its fluoride removal performance was investigated in batch experiments. The properties of the sorbent and the mechanism of fluoride removal were characterized by SEM, EDX and XPS. The effect on the sorption performance of various factors of initial pH, initial fluoride concentration, contact time, and sorption temperature were examined by batch experiments. The experimental data were fitted to the Langmuir and Freundlich model, and the maximum sorption capacity was calculated to be 98.077 mg g⁻¹. Meanwhile, the results showed that the sorption kinetic data was well fitted to pseudo-second-order. The thermodynamic parameters of ΔH⁰, ΔS⁰ and ΔG⁰ calculated according to the study showed that the process of fluoride removal was spontaneous and exothermic. The pectin/Al₂O₃–ZrO₂ core/shell bead sorbent could be considered as an effective sorbent for fluoride removal compared with other sorbents.