The effect of surface modification on heavy metal ion removal from water by carbon nanoporous adsorbent

In this work, chemically oxidized mesoporous carbon (COMC) with excellent lead adsorption performance was prepared by an acid surface modification method from mesoporous carbon (MC) by wet impregnation method. The structural order and textural properties of the mesoporous materials were studied by XRD, SEM, and nitrogen adsorption. The presence of carboxylic functional groups on the carbon surface was confirmed by FT-IR analysis. Batch adsorption experiments were conducted to study the effect of adsorbent dose, initial concentration and temperature for the removal of Pb(II) from aqueous systems. The adsorption was maximum for the initial pH in the range of 6.5–8.0. The kinetic data were best fitted to the pseudo-second order model. The adsorption of chemically oxidized mesoporous carbon to Pb(II) fits to the Langmuir model. The larger adsorption capacity of chemically oxidized mesoporous carbon for Pb(II) is mainly due to the oxygenous functional groups formed on the surface of COMC which can react with Pb(II) to form salt or complex deposited on the surface of MC.