Preparation and sorption studies of β-cyclodextrin–chitosan–glutaraldehyde terpolymers

β-Cyclodextrin–chitosan–glutaraldehyde terpolymers were synthesized by reacting variable weight fractions of β-cyclodextrin (β-CD) and chitosan (Chi), with a constant amount of crosslinker (glutaraldehyde). The β-CD:Chi:Glu terpolymer sorbents were characterized by FT-IR spectroscopy and TGA. The solid-solution sorption isotherms in aqueous solution for the copolymers were characterized using two spectroscopic methods (UV–Vis and ICAP-OES) for p  -nitrophenol (PNP) and the arsenate oxoanion (HAsO42-) at alkaline pH conditions. The Sips isotherm model was utilized to obtain sorption parameters at pH 8.5 and 295 K (i.e. sorbent surface area, sorption capacity and removal efficiency) for each copolymer sorbent. The sorbent surface area estimates for the terpolymers at low (T1), medium (T2), and high (T3) weight fractions of β-CD are listed in parentheses (m2 g−1), as follows: T1 (161), T2 (51.2) and T3 (275). The removal efficiencies are dependent on the relative weight fraction of the polysaccharide components (i.e. β-CD and Chi); whereas the removal efficiencies for p  -nitrophenolate ranged between 7.3% and 28%, and H2AsO42- ranged between 23% and 55%.

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► Terpolymers were prepared containing chitosan, β-cyclodextrin (β-CD), and glutaraldehyde.
► Adsorption of p  -nitrophenolate (PNP) and arsenate (HAsO42-) anions were observed in aqueous solution.
► Tunable anion sorption properties were observed according to variable β-CD and chitosan content.