Activated Carbon from the Chinese Herbal Medicine Waste by H3PO4 Activation

Large amounts of Chinese herbal medicine wastes produced by the medicinal factories have been mainly landfilled as waste. In this study, via phosphoric acid activation, a Chinese herbal medicine waste from Magnolia officinalis (CHMW-MO) was prepared for activated carbon (CHMW-MO-AC). The effect of preparation conditions (phosphoric acid/CHMW-MO impregnation ratio, activation temperature, and time) of activated carbon on yield of CHMW-MO-AC was investigated. The surface area and porous texture of the CHMW-MO-ACs were characterized by nitrogen adsorption at 77 K. The and pore volume were achieved in their highest value of 920 m2/g and 0.703 cm3/g, respectively. Thermal gravity analysis and scanning electron microscope images showed that CHMW-MO-ACs have a high thermal resistance and pore development. The results indicated that CHMW-MO is a good precursor material for preparing activated carbon, and CHMW-MO-AC with well-developed mesopore volume can be prepared by H3PO4 activation.