Assessment of activated carbon prepared from corncob by chemical activation with phosphoric acid

Corncob, which is the main waste from corn agricultures in Egypt, has been used as a raw material for the preparation of different activated carbons. Activated carbons (ACs) were prepared by chemical activation with concentrated H3PO4 acid; followed by pyrolysis at 400, 500 and 600 °C. Different ACs have been used for the removal of methylene blue (MB) dye from aqueous solutions. Batch adsorption experiments were performed as a function of initial dye concentration, contact time, adsorbent dose and pH. Adsorption data were modeled using the Langmuir and Freundlich adsorption isotherms. Adsorption of MB on AC1 (R2=0.9868) and AC2 (R2=0.9810) followed Langmuir model with maximum monolayer sorption capacity of 28.65 and 17.57 mg/g, respectively. Adsorption onto AC3 was better fitted to Freundlich isotherm model (R2=0.9823).