Abstract
Through different scientific researches and empirical cases, it has been shown that compounds of Cr (VI), which are widely used in the tanning industry, are lethal, even at low concentrations. This situation arises the need to make effective treatments to effluents from the process and the activated carbon (AC) may be useful for treating the wastewater with low chromium concentration. The main objective of this work was to evaluate the behaviour of three different shapes of an AC obtained from the endocarp Colombian palm oil. Batch experiments were conducted based on specific experimental parameters, and the studies included an analysis of the kinetics of adsorption, Freundlich and Langmuir adsorption isotherms, pseudo-first and pseudo-second order kinetic, and a diffusion mechanism. The adsorbed amount of hexavalent chromium until the equilibrium was related with the surface area and pore size, which were obtained by BET analysis. The equilibrium data fitted well to Freundlich isotherm model, suggesting that the removal of hexavalent chromium is performed because of the energy distribution of the adsorption active sites and absence of monolayers. Finally, kinetic studies showed a better fit to the pseudo-second order model.
