Production and detailed characterization of bean husk-based carbon: Efficient cadmium (II) removal from aqueous solutions

We report the production of a modified carbon by heat treating bean husk (Phaseolus vulgaris) at 270 °C in Ar, followed by chemical activation using HNO3. The material was studied using thermogravimetric analysis (TGA), infrared spectroscopy (IRS), high-resolution transmission electron microscopy (HRTEM), elemental mapping, energy dispersive X-ray spectroscopy (EDX), X-ray powder diffraction and scanning electron microscopy (SEM). Cd2+ sorption studies with this material were carried out at different concentrations. It was found that cadmium (II) is effectively removed by the modified material obtained from bean husk (180 mg/g). The sorption mechanism is discussed in terms of the activated surface properties. A relationship between the oxygen content and sorption was found in this novel material. Commercial activated carbon (AC) (F400) was used for comparison.