Adsorbents for Cr(VI) Uptake from Contaminated Water: Part I Activated Carbon

Abstract

Chromium in its hexavalent form (Cr(VI)) poses a significant threat to the environment and human health due to its toxicity, mobility, and bioaccumulation capacity. This paper presents a study on the removal of Cr(VI) from aqueous solutions using three types of activated carbon: BIOMUS PYL 22 (PAC), NORIT 1240 (GAC), and SORBOTECH LGCO (GAC). The effects of key process parameters, such as contact time, stirring speed, pH, temperature, initial Cr(VI) concentration, and sorbent dosage, on adsorption efficiency were analyzed. The results indicate that powdered activated carbon (PAC) exhibits the highest Cr(VI) removal efficiency, reaching 80–90% under optimal conditions. Cr(VI) adsorption is most effective at acidic pH (~2) and elevated temperatures (40–60°C), although high removal efficiencies were also achieved at room temperature. The Langmuir and Freundlich isotherm models confirm the favorable nature of the adsorption process. These results provide a basis for designing efficient and economically viable processes for the removal of Cr(VI) from industrial wastewater.