Preparation of activated carbon from waste leaf blade of Japanese leek and its p-cresol adsorption capacity

Abstract

Tips of the leaf blades of Japanese leeks are cut off and discarded at harvest, resulting in a large amount of waste in Japan. In this study, the waste leaf blade was used as raw material to produce activated carbon. The activated carbon was prepared by adding beet sugar syrup to the pre-carbonized waste leaf blade, which was then carbonized and physically activated with CO₂ gas. The specific surface area, and micro- and meso-pore volumes increased with increasing activation time. The maximum specific surface area reached 1852.7 m²/g at an activation time of 3h. The leaf blade activated carbon had high adsorption capacity for p-cresol. Langmuir adsorption isotherms revealed that the maximum adsorption capacity of the leaf blade activated carbon was 401.5 mg/g, which was approximately 2.0 and 1.7 times that of commercial coal-based activated carbon and coconut shell activated carbon, respectively.