Performance and mechanism study on phosphate adsorption onto activated carbon fiber loading lanthanum and iron oxides

Abstract

A hybrid sorbent of lanthanum and iron oxides doped onto activated carbon fiber (ACF–LaFeO) was developed for the removal of phosphate from water. The effects of n (La)/n (Fe), total metal ion concentration, activation time, and activation temperature on the sorbent performance were studied by single-factor method. Response surface method (RSM), based on three-variable, three-level Box–Behnken design (BBD), was used to optimize the preparation parameters. The phosphate adsorption mechanism was investigated by Brunauer–Emmett–Teller (BET) analysis, Fourier transform infrared (FT–IR) spectroscopy analysis, and the test of adsorption amount dependence on the solution pH. The possible adsorption mechanisms could be a combination of electrostatic interaction, ion exchange, and Lewis acid–base interactions, depending on solution pH.

Keywords:

• Phosphate adsorption
• Lanthanum iron oxides (LaFeO)
• Activated carbon fiber (ACF)
• Response surface method (RSM)
• Mechanism

Acknowledgments

The work was supported by National Natural Science Foundation of China (21207085, 41472312), Innovation Program of Shanghai Municipal Education Commission (14YZ014) and Program for Innovative Research Team in University (IRT13078).