AbstractBiosorption was carried out in a batch process to test the suitability of corncob for the removal of manganese ion (Mn(II)) from aqueous solution. The amount of metal ions removed from solution depended on the metal ion-substrate contact time, ion concentration, temperature, and pH. The adsorption capacity of the biosorbent from corncob was also enhanced by treatment with acid. Kinetic modeling of the data obtained from the study showed that the biosorption of Mn(II) ions by the untreated and acid-treated corncob followed the Largergren pseudo-first order model. The adsorption capacity of the raw biomass was found to be 6.54 mg/g, while acid-treated biomass showed an adsorption capacity of 7.87 mg/g. The data obtained from this study fitted well with the Freundlich and Langmuir adsorption isotherms.