A comparative study on the kinetics and mechanisms of removal of Reactive Black 5 by adsorption onto activated carbons and bone char

The adsorption of a large reactive dye, Reactive Black 5, onto four adsorbents has been studied. A commercial active carbon, F400, was selected as a standard and two active carbons prepared from bamboo, a biomaterial. The two bamboo derived carbons, BACX2 and BACX6 had high specific surface areas, namely, 2123 and 1400 m2/g, respectively. A fourth widely used adsorbent, bone char, was also tested. The adsorption capacities for F400, bone char, BACX2 and BACX6 were 198, 160, 286 and 473 mg/g, respectively. A series of batch kinetics were carried out to investigate the rate and possible mechanism of Reactive Black 5 adsorption. Two pseudo-kinetic models and one intraparticle diffusion model were tested. The experimental concentration versus time decay curves were best explained by the intraparticle diffusion model.