Abstract
Sorption properties of surface modified activated carbon (AC) with p-nitrophenol (PNP) and methylene blue (MB) in aqueous solution were investigated. The calculated surface areas for AC and surface modified AC were compared using nitrogen sorption and a dye-based method. The surface areas of AC and the surface modified AC with glutaraldehyde (AC-β-CD) (1:10:10(9)) and 1,4-phenylene diisocyanate (ACPDICD) measured by nitrogen sorption were 1,269 m2/g, 103 m2/g, and 95 m2/g, respectively (Langmuir model) and 956 m2/g, 74 m2/g, and 69 m2/g (BET model), respectively. However, the calculated surface areas for the dye-based method (PNP; pH 6.00) for AC, AC-β-CD(1:10:10(9)), and ACPDICD was 1,035 m2/g, 814 m2/g, and 76 m2/g (Langmuir model), respectively and 1,491 m2/g, 1,669 m2/g, and 92 m2/g (BET model), respectively. The corresponding surface areas for the dye-based method (MB; pH 8.40) for AC-β-CD(1:10:10(9)) and ACPDICD was 263 m2/g and 171 m2/g (Langmuir model), respectively and 1019 m2/g and 182 m2/g (BET model), respectively. The sorption capacity (Qm ) and binding affinity characteristics [KF (L/g), KL (g/mol), and KBET (L/g)] were estimated at room temperature at equilibrium conditions using several sorption isotherm models.
Acknowledgments
We acknowledge NORIT America Ltd. for their kind provision of AC, and NSERC, the University of Saskatchewan, and CFI for their support of this research.