Fabrication and characterization of a novel biosorbent and its evaluation as adsorbent for heavy metal ions

Abstract

Firstly, gelatin type B was extracted from the black tilapia fish wastes, and in the following, a novel gelatin-based nanocomposite biosorbent was synthesized via free radical graft copolymerization of acrylic acid (AcA) and butyl methacrylate (BuMc) onto gelatin backbone in a homogeneous medium. The nanocomposite biosorbent structure was confirmed by FTIR, SEM, EDX, XRD and TGA techniques. The metal ion-loaded nanocomposite biosorbent was also characterized by FTIR, SEM and EDX analysis. The maximum of adsorption capacities 172.3 and 192.4 mg g−1 for Cd2+ and Cu2+ in single-ion system were determined under optimum conditions. The results of adsorption isotherms also showed that the Langmuir model described the adsorption mechanism better than the Freundlich. The kinetic adsorption for both metal ions was also followed the pseudo-second-order model. In addition, the biosorbent exhibited satisfactory adsorption capacities for the metal ions (162.4 mg g−1 for Cu2+ and 128.7 mg g−1 for Cd2+ at ambient temperature) in the local river water and in the presence of other metal ions, and as a result, this favorable material can be used to facilitate the reuse of valuable metals.