Preparation of activated carbons from wet activated sludge by direct chemical activation

摘要

An improved method for preparing activated carbons from wet waste activated sludge (WAS) byndirect chemical activation was studied in this paper. The effects of processing parameters onniodine adsorption capacity of the product were investigated. Results show that sludge-basednactivated carbon prepared with KOH had a larger iodine value than those activated with ZnCl2nand KCl. The maximum iodine value was observed at the KOH concentration of 0.50M. Increasingnthe impregnation time from 10 to 20 h resulted in a 20% increase in the iodine value. The highestniodine value was obtained at the activation temperature of 6008C and holding time of 1 h. Sludgenwater content had insignificant effects on the iodine value of products. Raw WAS with a waterncontent of 93.2% can be converted into an activated carbon with a high specific surface areanof 737.6m2ng21nand iodine value of 864.8mg g21nunder optimum experimental conditions. Othernphysical properties such as total pore volume, micropore volume and mean pore diameternof the product were also reported and compared with those of commercial activated carbon.