Biomass-derived porous carbon highly efficient for removal of Pb(II) and Cd(II)

Abstract

The utilization of abundant and renewable biomass to fabricate advanced functional materials is considered a promising route for environmental applications. Herein, Lignin-based porous carbon with layered graphene-like structure (LPC) is successfully synthesized and applied to efficiently remove Pb(II) and Cd(II). The as-synthesized LPC materials are systematically characterized and these results show that LPC has a porous graphene-like structure, facilitating the diffusion and immobilization of heavy metal ions. The influence of different reaction parameters (solution pH, initial concentration of metal ions, contact time and adsorbent amount) on the adsorption performance is investigated in details. The results demonstrate that LPC can achieve superior adsorption capacities of 250.5 mg g−1 for Pb(II) and 126.4 mg g−1 for Cd(II), which are far superior to the previously reported adsorbents. Pseudo-second order kinetics model and Freundlich isotherm model describe the adsorption process well. Furthermore, the exhausted LPC can be regenerated easily and exhibits the removal efficiency of 96% and 92% for Pb(II) and Cd(II) after five continuous runs, respectively. This study shows a sustainable strategy for the design of porous carbon material from naïve biomass and highlights the great potential in wastewater treatment. Keywords: Porous carbon, Layered structure, Heavy metals, Adsorption kinetics, Recyclability