Abstract

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Currently much of the lignin produced in paper and pulp industry is consumed as a waste which is generally used only for its fuel value; therefore it can be of interest to prepare a high value and low cost product such as activated carbon from lignin. High surface area activated carbon was obtained by chemical activation of industrial waste lignin with H₃PO₄. To optimize the preparation method, the effect of the main process parameters such as H₃PO₄/lignin impregnation ratio, activation temperature and activation time on the iodine number and N₂-BET surface area were studied in detail. The activated carbon obtained were analyzed by its proximate and elemental analysis, FTIR characterization and SEM analysis. The surface textural properties were determined by surface area determination by N₂-BET isotherm and pore volume. The lignin based activated carbon with maximum surface area (~1343.98 m²/g) and pore volume (~0.6950 cm³/g ) was obtained with H3PO4-to-lignin impregnation ratio of 1:1, the activation temperature 800°C and the activation time 1 h . The adsorption capacity of prepared activated carbon has been tested for the decolourization of wastewater containing organic pollutant such as methylene blue dye. The effect of system variable such as concentration, pH, contact time and adsorbent dosage are investigated. The adsorption data was fitted with both Langmuir and Freundlich adsorption isotherms models.

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