Adsorption of Cd(Ⅱ) from aqueous solution by modified activated carbon made from activated sludge
改性污泥活性炭对水中镉离子的吸附性能

Activated carbon was prepared from excessive sludge from municipal wastewater treatment plant, and zinc chloride was used as the activation reagent. The activated carbon from sludge was also treated using 6.0 mol/L nitric acid to prepare modified activated carbon. The performances of the two types of activated carbon for Cd2+ adsorption were compared. Results show that the adsorption capacity of the unmodified activated carbon and modified activated carbon was 8.45 and 23.35 mg of Cd2+ per g of activated carbon, respectively at a pH of 5.0, an initial concentration of Cd2+ of 100 mg/L, and a dosage of activated carbon of 2.0 g/L. Therefore, these two types of activated carbon had good adsorption capacities, and the modification by nitric acid greatly improved the adsorption performance for Cd2+. At room temperature, the adsorption of Cd2+ by the modified sludge activated carbon accords with the Langmuir equation pretty well.