Synergic adsorption of acid blue 80 and heavy metal ions (Cu2+/Ni2+) onto activated carbon and its mechanisms

A novel synergic adsorption process of acid blue 80 dye (AB80) and heavy metal ions (Cu2+ or Ni2+) on a low-cost activated carbon (PRAC) which was prepared from potato residue was reported. The results indicated that the maximum adsorption capacity of PRAC for AB80 and Cu2+ were 294.7 mg/g and 45.0 mg/g in the AB80-Cu2+ system, respectively. In the mono-component system, the values were 173.0 mg/g and 26.8 mg/g, respectively. Compared with mono-component system, the AB80 and Cu2+ showed good synergistic effect on PRAC. The similarly result was revealed in the AB80-Ni2+ system. For a binary system, the adsorption isotherm of AB80 and heavy metal ions followed the non-modified Sips model, and the adsorption kinetic models followed the pseudo-second order kinetic model. The effect of pH also was discussed, and showed significant role in the binary-component system adsorption. The selectivity in synergic adsorption was discussed. BET, FE-SEM/EDX and XPS were used to characterize PRAC with and without adsorbed dye and heavy metal ions, possible mechanisms of AB80 and heavy metal ions synergic adsorption process were proposed. (C) 2015 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.