Abstract:
This study investigated, in batch studies, the removal of Cr(VI) from aqueous solutions, by adsorption on commercially granular activated carbon (GAC) Nobrac CG 700. The influence of pH on the efficiency of the Cr(VI) adsorption process was evaluated at 25o/ C, over the pH range of 1 - 3. Sorption data have been interpreted in terms of Langmuir and Freundlich isotherm equations, and their constants were evaluated. The results show that the adsorption capacity and the adsorption intensity increased with the decrease of pH. Although the determined values of ΔG0298 indicate the spontaneous and exothermic nature of the adsorption process over the entire studied pH range, Cr(VI) adsorption was thermodinamically less favored under very strong acidic conditions (pH = 1.10).
Keywords:
hexavalent chromium, heavy metals, activated carbon, adsorption
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