Simultaneous removal of methyl orange and Cr(VI) using polyethyleneimine-modified corncob-derived carbon material

Polyethyleneimine (PEI) modified corncob-derived carbon material (CCM) was prepared by the simple wet-impregnation technique. Field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDS), Fourier-transform infrared spectroscopy (FT-IR), and nitrogen isothermal adsorption/desorption measurements were used to compare the structural differences between the CCM and the PEI-modified CCM (PEI-CCM). In the single-pollutant removal experiment, the PEI-CCM showed high adsorption capacities for methyl orange (MO) and Cr(VI). However, the CCM only showed high adsorption capacity for MO. Moreover, the PEI-CCM exhibited high removal efficiencies in the simultaneous removal of MO and Cr(VI), with final removal efficiencies of 100% and 95%, respectively. The reusability experiment of PEI-CCM indicated that, after four recycles, PEI-CCM maintained high performance with the removal efficiency of MO and Cr(VI) decreased less than 3% and 16%, respectively. The prepared PEI-CCM could be a high-performance adsorbent for the simultaneous removal of MO and Cr(VI) from water containing multiple pollutants.