Abstract: The activated carbon was prepared from walnut shell with ZnCl₂ by microwave irradiation. The effect of activation conditions on the decolorizing capacity for methylene blue, iodine value and the yield of activated carbon were investigated. The optimal technical conditions were: walnut shell was 10 g, microwave power was 580 W, activation time was 7 min, ZnCl₂ solution concentration was 50%. The decolorizing capacity for methylene blue of activated carbon was 16 mL/g, the iodine value was 977.81mg/g, and the yield was 51.06%. The activation time was as short as 7/90 of the time for traditional technology and the yield was 1.5 times higher than that of the traditional technology.

Key words: microwave irradiation, walnut shell, activated carbon, technology