Remediation of water using Theobroma Cacao pod-based activated carbon: A novel approach as determined by highly sensitive BiNP/MWCNT/Nafion-modified GCE

Rapid urbanization and industrial pollution have led to the generation of enormous waste in water. A standard method of waste removal in water; specifically, of heavy metals is not yet realized. To resolve the problem, the pursuit of exploring alternative environment-friendly waste removal using carbonized biowaste materials such as the Theobroma Cacao pods was undertaken. Activated carbon from the cacao pods was synthesized via activation with ZnCl2 and was subsequently used for the removal of heavy metals from contaminated water samples. Bismuth nanoparticles (BiNP)/multi-walled carbon nanotubes (MWCNT)/Nafion®-modified glassy carbon electrode (GCE) was fabricated and was used as the working electrode in anodic stripping voltammetry for heavy metal detection. The working electrode was optimized to obtain its optimum efficiency for detecting Zn2+, Cd2+, and Pb2+. The voltammograms showed a decrease of 24% to 81% in the concentrations of the heavy metals after remediation of the water samples by the activated carbon. This is attributed to the porous structure, large surface area and high adsorption capacity of the activated carbon. Hence, the ZnCl2-activated carbon from cacao pods is a promising material for water remediation. © 2019 IOP Publishing Ltd