Preparation and adsorption properties of magnetic mesoporous Fe₃C/carbon aerogel for arsenic removal from water

Abstract

Carbon materials are effective for removal of both toxic inorganic and organic substances. In this study, a novel magnetic mesoporous carbon aerogel which combined high specific surface area, adsorption capacity and magnetic property of Fe₃C was prepared by citrate sol-gel method. The as-prepared samples were characterized by powder X-ray diffraction, TEM, scanning electron microscope, and BET methods. Results show that the aerogel has the specific surface and average pore size of 290 m²/g and 2.7 nm, respectively. Magnetic Fe₃C nanoparticles were dispersed uniformly in carbon matrix and exhibit excellent response to an external magnetic field. As a result, the adsorbent can be easily separated from solution using an external magnetic field. Batch experimental results on As(V) removal showed that the adsorption kinetics and isotherm data were fitted well by a pseudo-second-order model and a Freundlich model, respectively. The monolayer adsorption capacity (q_m) of the adsorbent was calculated to be 56.2 mg/g at pH 7.0. The excellent uptake capability of the magnetic mesoporous materials make it be potentially attractive materials for removal of hazardous substances from water.

Keywords:

• Arsenic removal
• Adsorption kinetics and isotherm
• Adsorption capacity
• Mesoporous magnetic Fe₃C/Carbon aerogel

Acknowledgments

This work has been supported by Jiangsu Overseas Research & Training Program for University prominent young and middle-aged teachers and presidents and Science and Technology on Near-Surface Detection Laboratory.