SYNTHESIS OF ACTIVATED CARBON FROM JATROPHA SEED COAT AND APPLICATION TO ADSORPTION OF IODINE AND METHYLENE BLUE |
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Authors: | Samorn Hirunpraditkoon Penjit Srinophakun Narumon Sombun Elvin J Moore |
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Affiliation: | 1. Department of Chemical Engineering, Faculty of Engineering , King Mongkut's University of Technology North Bangkok , Bangsue , Bangkok , Thailand samornh@hotmail.com;3. Department of Chemical Engineering, Faculty of Engineering , Kasetsart University , Lat Yao, Chatuchak , Bangkok , Thailand;4. Department of Mathematics, Faculty of Applied Science , King Mongkut's University of Technology North Bangkok , Bangsue , Bangkok , Thailand |
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Abstract: | This article provides evidence that jatropha seed coat residues can be used as a carbon source for preparing activated carbons that have good adsorption properties for iodine and methylene blue. Activated carbons were prepared using three different methods of activation, physical, chemical, and physico-chemical, for a range of activation temperatures (600°, 700°, 800°, and 900°C) and activation hold times (1, 2, and 3 h). The highest BET surface area (1479 m2 g?1) and the highest iodine adsorption (1511 mg g?1) were obtained with physico-chemical activation at a temperature of 900°C and a hold time of 2 h. This activated carbon gave higher BET surface area and iodine adsorption than commercial activated carbon (1169.1 m2 g?1 and 1076 mg g?1). The activated carbons prepared by physico-chemical activation at 900°C and 2 h were then tested for adsorption of methylene blue at a range of concentrations of methylene blue (100, 200, 300, 400, and 500 mg L?1). It was found that a Langmuir isotherm gave a better fit (R 2 = 0.999) to the observed adsorptions than a Freundlich isotherm (R 2 = 0.884). For the adsorption kinetics, a pseudo-second-order model gave a better fit (R 2 > 0.998, Δq e = 3.7%) than a pseudo-first-order model (R 2 ≈ 0.95, Δq e = 85.6%). These results suggest that chemisorption is the rate-controlling step for the adsorption of methylene blue. The experimental results show that jatropha seed coat is a lignocellulosic waste precursor for preparation of activated carbon that is an alternative source for preparation of commercial-grade activated carbons. |
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Keywords: | Activated carbon Iodine Jatropha seed coat Kinetics Methylene blue |
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