Removal of Hexavalent Chromium from Bichromate Effluents using Activated Carbon Derived from Coffee Grounds

The aim of this study is to evaluate the efficacy of a synthesized carbon derived from coffee grounds in the adsorption of chromium VI present in bichromate effluents used during uranium analysis. A comparison with a commercial activated carbon is made under the identical conditions. Chromium is detected in the effluents at a concentration of 582 mg/L. However, following its use in uranium analysis, the measured chromium concentration decreases to 181.87 mg/L. It’s worth noting that both activated carbons share similar physical characteristics, including a particle size of approximately 1000 μm and closely matched specific surface areas, around 936 m²/g for the synthesized activated carbon and 1100m²/g for the commercial one. Parametric studies indicate that the adsorption of chromium VI by coffee grounds is favored at acidic pH values. The maximum adsorption capacity of chromiumVI determined for the synthesized activated carbon is 50.65mg/g for the commercial activated carbon; it is 56.86mg/g.