Chemical Science International Journal

Adsorption of Fe³⁺/Fe²⁺ from a polluted shallow well water onto a palm kernel shell activated carbon (PKSAC) has been studied.  Batch experiment was adopted to study the Removal efficiency of Fe³⁺/Fe²⁺ on varying contact time, temperature, adsorbent loading and concentrations. Equilibrium isotherm and kinetic were also studied. Removal efficiency progressed with contact time till the peak adsorption time of 100 minutes when the efficiency remained at equilibrium. Also, removal efficiency got to equilibrium at the peak values of 80ºC, 4.8g and 12.5mg/l for temperature, adsorbent loading and concentration variations respectively. The adsorption isotherm models fitted the isotherm data got at 25ºC, 40ºC and 80ºC in this order; Langmuir > Temkin>Freunlich.  The dimensionless separation factor of 0.012, 0.017 and 0.015 for 25ºC, 40ºC and 80ºC respectively confirmed favorable adsorption of Fe³⁺/Fe²⁺ on the PKSAC adsorbent. Langmuir  adsorption capacity  increased from 203.9mg Fe³⁺/Fe^2+/g to 389.3 mg Fe³⁺/Fe^2+/g when the temperature increased from 25ºC to 40ºC but decreased to 308.1 mg Fe³⁺/Fe^2+/g  at temperature of 80ºC. The kinetic models described the kinetic study data got at 25ºC, 40ºC and 80ºC as follows; power-function>second-order>Elovick>intra-diffusion>first-order kinetics. Mass transfer through liquid film diffusion controlled the adsorption of Fe³⁺/Fe²⁺ onto PKSAC. Negative values of the Thermodynamic parameters ( ,  and ) got at various temperature values showed   favorability of adsorption of Fe^3+/Fe²⁺ onto PKSAC. It is therefore concluded that PKSAC removed Fe^3+/Fe²⁺ from aqueous solution.