Nanocellulose from Banana Pseudostem for Pb2+ and Cd2+ Ions Removal from Aqueous Solutions

Banana pseudostem nanocellulose for Pb2+ and Cd2+ ions removal

Abstract

The aim of this study was to investigate the removal of Pb and Cd ions from aqueous solutions using Nanocellulose (NC) extracted from banana pseudostem fiber. The microstructure and properties of nanocellulose were characterized using various techniques, including Fourier transform infrared (FTIR), transmission electron microscopy (TEM), energy dispersive X-ray (EDX) coupled with field emission scanning electron microscopy (FE-SEM), and Brunauer-Emmett-Teller (BET) analysis. The adsorption process was evaluated by analyzing several influencing factors, including pH (3 –7), contact time (20 – 100 min), initial concentration (10 – 50 mg/L), and adsorbent dose (0.05 – 0.25 g). The kinetics of adsorption were studied using the pseudo-first-order and pseudo-second-order models, while the adsorption isotherms were analyzed using the Langmuir and Freundlich models. Optimal adsorption conditions were determined to be pH 5 for Pb²⁺ and pH 6 for Cd^2+, with a contact time of 60 minutes. The NC achieved adsorption percentages of 96.22% and 92.5% for Pb²⁺ and Cd²⁺, respectively, with corresponding adsorption capacities of 24.02 mg/g and 20.54 mg/g. The findings demonstrate that the adsorption process of Pb²⁺ and Cd²⁺ onto the surface of NC followed the 2^nd order kinetic, as evidenced by the high values of (R²) 0.98019 and 0.98428 for Pb and Cd ions, respectively, compared to the 1^st order model with values of 0.8048 and 0.67804.  Furthermore, the Langmuir model was found to be a better fit for the adsorption process, with (R²) values of 0.97001 and 0.94761 for lead and cadmium ions, respectively, compared to the Freundlich model with values of 0.93307 and 0.9086. The BET analysis showed a surface area of 52.3891 m²/g for NC. The results of the adsorption process at optimal conditions indicate that the surface of the NC is somewhat effective in the adsorption of lead and cadmium ions from aqueous solutions.