Removal of Cu(II) by activated carbon impregnated with iron(III)

Fe-impregnated activated carbon (Fe-AC) was prepared by loading of Fe(III) on activated carbon (AC) at different preparations of pH. From the stability test of Fe-AC in acidic conditions, the dissolved iron was below the effluent standard of iron (2 ppm) in Korea, suggesting a strong acid-proof property. In the batch adsorption test, removal curves of copper shifted to the higher pH region as the copper concentration increased due to the finite number of adsorption sites on Fe-AC. From the strong chemical reaction between Fe(III) on AC and Cu(II), Fe-AC showed a greater adsorption capacity for Cu(II) than AC. Surface complexation modeling was performed by considering inner-sphere complexation reaction and using the diffuse layer model with MINTEQA2/PRODEFA2 program. The model predictions considering adsorption and precipitation generally well simulated the experimental removal trends of copper over the entire pH ranges. From the column test, Fe-AC was regarded as a promising filter material in the treatment of acidic wastewater contaminated with copper with proper controlling of the contact time between copper and Fe-AC.