A novel natural chitosan/activated carbon/iron bio-nanocomposite: Sonochemical synthesis, characterization, and application for cadmium removal in batch and continuous adsorption process.

The natural chitosan was synthesized using shrimp shells via sonochemical method, and activated carbon produced from grape stalks biomass. The novel bio-nanocomposite of chitosan/activated carbon/iron nanoparticles was synthesized via the sonochemical method and characterized using FTIR, SEM, and BET techniques. This bio-based nanocomposite was utilized to cadmium removal from dilute solution. The adsorption process via batch method was optimized, and the impacts of pH of feed, the dosage of adsorbent, and concentration of cadmium were analyzed. The kinetics and equilibrium analysis was done, and results indicate the predomination of chemical absorption and the single-layer adsorption process. Langmuir data indicates that the synthesized bio-nanocomposite can adsorb 344 mg cadmium per each gram. To evaluate the ability of the synthesized nanocomposite in the industrial application, the adsorption tests were done in a continuous adsorption system in three cycles.