Epichlorohydrin crosslinked carboxymethyl cellulose-ethylenediamine imprinted polymer for the selective uptake of Cr(VI)

A new ion-imprinted polymer (IIP) was synthesized from sodium carboxymethyl cellulose and used for the adsorption of hexavalent chromium from aqueous solution. Epichlorohydrin was used to stabilize the polymer before ethylenediamine (EDA) ligand and Cr(VI) were introduced. The obtained IIP was characterized with FTIR, XPS, TGA,13C NMR, SEM, EDX, BET and zeta sizer. The kinetics of adsorption followed a pseudo-second-order model while the Langmuir adsorption isotherm provided the best fit with a maximum adsorption capacity of 177.62 mg/g at 25 °C. The Langmuir adsorption capacity for the non-imprinted polymer (NIP) at 25 °C was 149.93 mg/g. Thermodynamic parameters indicated an endothermic process and spontaneous adsorption of Cr (VI) on the polymers. IIP adsorbent was successfully recycled 5 times using 0.1 M NaOH as a leachate; 98% Cr(VI) was desorbed during the last adsorption-desorption cycle.