Adsorption Efficiency of Activated Carbon Produced from Corn Cob for the Removal of Cadmium Ions from Aqueous Solution

Studies were carried out to evaluate the adsorption efficiency of activated carbon produced from corn cob for the removal of Cd II ions from aqueous solution. The studies were carried out with due consideration of standard analytical procedures and instrumentation. Increase in the Cd II ions concentration from 90 to 180mg/l decreased the adsorption capacity of the adsorbent from 89.273 to 65.770%. Increase in the adsorbent's dosage from 0.5 to 2.0g increased the adsorption of Cd II ions from 81.522 to 91.980%. At pH of 5.0, the adsorption process attained equilibrium with a peak adsorption of Cd II ion at 93.628%. At a contact of time of 30mins between the adsorbate (Cd II ions) at the adsorbent; the adsorption of Cd II ions reached a peak value of 92.410%. The adsorption of Cd II ions on the surface of the activated carbon increased from 90.436 to 93.210% with increase in temperature from 40o to 160oC. The decrease in Gibb's free energy of adsorption of Cd II ions on the surface of the activated carbon revealed that the adsorption was favourable at high temperatures. The positive values of ∆H and ∆S shows that the adsorption process was endothermic.