The powdered activated carbon prepared by phosphoric acid activation was significantly affected by the carbonization temperature and the weight ratio between raw material and phosphoric acid. With an activation time of I h and an impregnation ratio of 1:1, the activated carbons with better adsorption capacity were obtained at 500 degrees C. A reduction in the adsorption capacity of the carbon product at higher acid content than this was observed, possibly due to the collapse of the micropore structure. The Properties of the resulting activated carbon were: bulk density 0.251 g cm(-3), ash content 4.88%, yield 26.2%, iodine adsorption 1043 mg g(-1), methylene blue adsorption number 427 mg g(-1), and BET surface area 1239 m(2) g(-1). (C) 2008 Elsevier Ltd. All rights reserved.