Removal of chromium Cr(VI) by low-cost chemically activated carbon materials from water.

Low-cost, chemically activated carbon materials, Pellet-600 and PVA-300, were prepared at relatively low temperatures and show more effective removal efficiency of Cr(VI) from water than commercially available activated carbons tested. The Pellet-600 is a pelletized carbon material with high mesoporous volumes and surface area, and the PVA-300 is composed of a high surface area carbon coating on a fiberglass mat substrate. A much faster adsorption kinetics and a much higher adsorption capacity for Cr(VI) are achieved by the Pellet-600. At very low concentrations of Cr(VI), the PVA-300 displays a strong adsorption ability for Cr(VI). XPS data show an increase in the atomic ratio of Cr/C and oxidation of carbon materials after adsorption of Cr(VI). These results suggest that a high content of mesopores with a high surface area and surface functional groups greatly improve the Cr(VI) removal efficiency from water.