Abstract
This work deals with the use of a supersorbent, i.e., sodium hydroxyethylcellulose succinate (HEC-Suc-Na), for the removal of Cd(II) ions from aqueous solution. HEC-Suc was fabricated via esterification of HEC with succinic anhydride in the presence of dimethylaminopyridine (DMAP) as a catalyst. The treatment of HEC-Suc conjugate with saturated NaHCO3 solution provided HEC-Suc-Na (sodic form). These acidic and sodic forms of the sorbent were characterized by Fourier transform infrared and energy-dispersive spectroscopy. The surface morphology and charge on the surface of sorbent were monitoredby SEM and pH corresponding to point of zero charge. Sorption data conceded well to the pseudo-second-order kinetic and Langmuir isotherm model. Maximum sorption capacity of HEC-Suc-Na for Cd(II) removal as calculated by Langmuir model was 714.2 mg g(-1). Moreover, no significant decrease in the sorption capacity of the sorbent was found after five regeneration cycles suggesting its repeated use. Thermodynamic parameters(Lambda G degrees, Lambda H degrees and Lambda S degrees) showed negative values that indicate spontaneity and exothermic nature of the sorption process. Removal of Cd(II) in presence of Ni(II) was also studied.