10th U6+ Consortium of African Universities International Conference

The discharge of untreated industrial wastewater containing cadmium (Cd), arsenic (As), and lead (Pb) that cause development of kidney disease in human into the environment has become a major public health and ecological concern. Conventional treatment methods are often expensive, inefficient at low concentrations and generate secondary pollutants. Therefore, the need for development of low-cost, sustainable, and highly efficient adsorbents is necessary. This study investigated the preparation, characterisation, and application of Desert Date (Balanites aegyptiaca) shell-derived carbon nanotubes for removal of Cd (II), As(III), and Pb(II) ions from industrial wastewater. The various Desert Date Shell Carbon Nanotubes types were compared with Commercial Multi-Walled Carbon Nanotubes (CMWCNTs). The adsorbents were characterised using standard physicochemical and spectroscopic methods such as Brunauer–Emmett–Teller (BET) surface area, Scanning Electron Microscopy (SEM) and so on. The results revealed high iodine numbers (628.2- 737.5 mg g⁻¹), low ash (0.55–0.82%), BET surface areas (184.4 – 325.6 m² g⁻¹), EDS (84.12 – 94.44% carbon). SEM micrographs revealed extensive pore development and interconnected adsorption-active surfaces, while FTIR analysis identified functional groups responsible for metal-ion binding. The application of the adsorbents to industrial wastewater demonstrated excellent removal efficiencies (99.80 – 99.99%) of the metal ions. These values satisfied the World Health Organisation (WHO) and Nigerian Industrial Standards (NIS) permissible limits for wastewater discharge. Kinetic studies revealed that the pseudo-second-order model described the adsorption behaviour best suggesting the involvement of surface interactions and diffusion-controlled processes. Thermodynamic Gibbs free energy values confirmed that the adsorption processes were spontaneous. The study established that Desert Date shell-derived carbon nanotubes performance for the removal of Cd (II), As (III), and Pb (II) ions from industrial wastewater compared well to the commercial carbon nanotubes for sustainable environmental remediation and industrial wastewater treatment applications.