Removal of Cadmium, Nickel, and Zinc from Aqueous Solutions by Activated Carbon Prepared from Corncob - Waste Agricultural Materials

Adsorption of zinc (Zn2+), cadmium (Cd2+), and nickel (Ni2+) from aqueous solutions by corncob (CC) and granular activated carbon prepared from corncob (GACC) were carried out. Synthetic solutions of Cd2+, Ni2+, and Zn2+ at 3.0 mg/L each were used to perform the adsorption process. A batch pattern was used to determine the removal efficiency of CC and GACC such as dose of adsorbents, contact time, and initial concentration of heavy metals, as well as kinetics studies and the adsorption isotherm parameters. The obtained results using either both the of CC and GACC separately were found to be matched with second-order model and the Langmuir isotherm model. Furthermore, the breakthrough study was conducted using CC, and GACC. The overall results in breakthrough curve indicated that adsorption of Cd2+> Ni2+> Zn2+, and Ni2+> Zn2+> Cd2+ on CC and GACC respectively. As demonstrated by R-2 and kinetic constant (k) values.