Application of Activated Carbon Banana Peel Coated with Al2O3-Chitosan for the Adsorptive Removal of Lead and Cadmium from Wastewater
Denga Ramutshatsha-Makhwedzha, Richard Mbaya, Mapula Lucey Mavhungu
Abstract
This study was aimed at evaluating the adsorption capacity of novel banana peel activated carbon (BPAC) modified with Al3O2@chitosan for the removal of cadmium (Cd2+) and lead (Pb2+) from wastewater. Characterization techniques such as X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Fourier transformed infrared (FTIR) spectroscopy, and Brunauer–Emmett–Teller analysis confirmed the synthesized BPAC@Al3O2@chitosan composite material. The univariate approach was used to study the influence of different experimental parameters (such as adsorbent mass, sample pH, and contact time) that affects simultaneous removal of Cd2+ and Pb2+ ions. Kinetic results showed that adsorption favored the pseudo-second-order kinetic model, whereas the adsorption of Cd2+ and Pb2+ was best described by the Langmuir model and the adsorption capacity for Cd2+ and Pb2+ was 46.9 mg g−1 and 57.1 mg g−1, respectively, for monolayer adsorption. It was shown the BPAC composite can be re-used until the third cycle of adsorption–desorption (% Re > 80). Based on the obtained results, it can be concluded that the prepared BPAC@Al3O2@chitosan composite material is cost effective, as it is generated from waste banana peels and can be re-used. In addition, the prepared material was able to remove Cd2+ and Pb2+ up to 99.9%.