Corn cob is an agricultural by-product worldwide available in large amounts. In this study, the potential of raw corn cob as a natural lignocellulosic waste material of no economic value was investigated for the removal of ammonium ions from aqueous solution. Sorption capacities of raw granular corn cob (GCC) for ammonium ions were evaluated in simulated and actual wastewater samples. The FT-IR analysis indicated the presence of different functional groups involved in a surface interaction with ammonium ions. Maximum removal efficiency of ammonium by raw GCC was found to be 56% achieved within 60 min contact time. Optimum pH range for the sorption of ammonium ions was found to be 4.5 to 9.5. The sorption of ammonium ions by GCC was best fitted to Freundlich isotherm. Pseudo-second order kinetic model was found to adequately describe the ammonium sorption process. In general, the results revealed that raw corn cob residues demonstrate good capacity for ammonium-nitrogen uptake.
Keywords: recycling, agricultural waste, corn cob, ammonium removal, sorption