Abstract—To prepare activated carbons (ACs) with higher BET specific surface area (SBET) and revealed granulated particles with higher dye adsorption, Japanese cedar (Cryptomeria japonica) ash was used as a natural activating agent and also a precursor for preparing ACs using precarbonization and subsequent combined two-stage of activations with wood ash and steam. The yield and iodine value of the prepared ACs were 9.1-21.3% and 502.4-1171.1 mg/g. When the activation temperature was 750
oC, the SBET was 1619-1758 m
2/g and the micropore volume (Vmi) was 0.26-0.33 cm
3/g, which were higher than that activated by K
2CO
3 (SBET 1537 m
2/g and Vmi 0.16 cm
3/g), and the required activation temperature was lower than the K
2CO
3 activation. Granular ACs (P200-0.25-750) at the yield of 14.9% and SBET 1619 m
2/g could be prepared under the conditions of precarbonization temperature of 200oC, ash to water ratio of 0.25 wt%, activation temperature of 750
oC, steam flow of 0.5 mL/min, and activation duration of 1.0 h, where the nitrogen adsorption-desorption isotherm type was Type IV, indicating the presence of micro/mesoporous structures mostly. The adsorbability of P200-0.25-750 for basic dye Auramine-O and Malachite green dye had simultaneous physical adsorption and ion exchange mechanisms, and in solutions onto prepared granular ACs were fitted with the Langmuir model with maximum adsorption capacity of 625.0 and 769.2 mg/g.
Index Terms—Activated carbons (ACs), precarbonization, wood ash, dye.
Chia-Wen Peng is with the Experimental Forest, College of Bio-Resources and Agriculture, National Taiwan University, Nantou, Taiwan (e-mail: s0981490@alumni.ncyu.edu.tw).
Han Chien Lin is with the Department of Wood Based Materials and Design, National Chiayi University, 60004 Chiayi, Taiwan (e-mail: alexhlin@mail.ncyu.edu.tw).
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Cite: Chia-Wen Peng and Han Chien Lin, "Adsorption for Dyes on Activation Carbons from Japanese Cedar Wood Prepared by Precarbonization and Two-stage Composite Activations with Wood Ash and Steam," International Journal of Chemical Engineering and Applications vol. 8, no. 4, pp. 277-285, 2017.
