Applied Surface Science, Vol.292, 735-741, 2014
Highly efficient adsorption of chlorophenols onto chemically modified chitosan
A novel chemically modified chitosan CS-SA-CD with phenol and beta-cyclodextrin groups was prepared. The adsorptions of phenol, 2-chlorophenol (2-CP), 4-chlorophenol (4-CP), 2,4-dichlorophenol (DCP) and 2,4,6-trichlorophenol (TCP) on the functional chitosan from aqueous solution were investigated. CS-SA-CD exhibited excellent adsorption ability for chlorophenols especially for DCP and TCP. The maximum adsorption capacities of phenol, 2-CP, 4-CP, DCP and TCP on CS-SA-CD were 59.74, 70.52, 96.43, 315.46 and 375.94 mg/g, respectively. The scanning electron microscope and Brunauer-Emmett-Teller analyses revealed that the introduction of phenol group changed the surface morphology and surface properties of chitosan. The modified chitosan CS-SA-CD possesses larger surface areas (4.72 m(2)/g), pore volume (7.29 x 10(-3) mL/g) and average pore diameter (59.99 angstrom) as compared to those of chitosan 3.27 m(2)/g, 2.00 x 10(-3) mL/g and 15.95 angstrom, respectively. The enhanced adsorption of chlorophenols was also attributed to the interaction of hydrogen bond between Cl atom and -OH group. The adsorption of chlorophenols on CS-SA-CD followed the pseudo-second-order kinetic model. Adsorbent could be regenerated easily and the regenerated CS-SA-CD remained 80-91% adsorption efficiency. (C) 2013 Elsevier B.V. All rights reserved.