Adsorption Behavior of Al2O3 Nanoparticles in the Treatment of Heavy-Metal-Laden Pharmaceutical Effluents
Authors: *Okoye, J.N., Egbosiuba, T.C., Umeuzuegbu, J.C., Mustapha, S., Ezeugo, J.O. And Kamuche, T.
DOI Info: http://doi.org/10.5281/zenodo.21045262
ABSTRACT
Heavy metal contamination in pharmaceutical wastewater remains a critical environmental concern due to the toxicity of Ni, Fe, Cr, and Pb. This study evaluates aluminum oxide (Al2O3) nanoparticles as an efficient adsorbent for the removal of these heavy metals from pharmaceutical effluents. Al2O3 nanoparticles were synthesized via a controlled precipitation method and characterized using X-ray diffraction (XRD), high-resolution scanning electron microscopy (HRSEM), Energy dispersive X-ray (EDX), High-resolution transmission electron microscopy (HRTEM), and Selected area electron diffraction (SAED). The XRD patterns confirmed the formation of highly crystalline a-Al2O3, while HRSEM images revealed well-defined spherical particles with porous networks, and EDX spectra verified the presence of aluminum and oxygen, indicating high purity. HRTEM and SAED demonstrated distinct lattice fringes and polycrystalline diffraction rings. BET analysis showed a high surface area and mesoporous structure, enhancing adsorption potential. Batch adsorption experiments assessed the effects of contact time, adsorbent dosage, and temperature on removal efficiency. Results indicated rapid adsorption within the first 30 minutes, reaching equilibrium at approximately 50 minutes. Also, removal efficiency increased with dosage, achieving nearly 100% removal at 0.6–0.7 g. Adsorption improved at higher temperatures, indicating an endothermic process. BET isotherm modeling demonstrated strong adsorption affinity, particularly for Cr. Kinetic analysis showed that metal ion uptake followed a pseudo-second-order model, signifying chemisorption. Thermodynamic parameters confirmed the spontaneity of the process. Overall, Al2O3 nanoparticles demonstrate strong potential as a low-cost and environmentally sustainable adsorbent for the treatment of heavy-metal-laden pharmaceutical wastewater.
Affiliations: Department of Chemical Engineering, School of Engineering Technology, Chukwuemeka Odumegwu Ojukwu University, Uli, Anambra State, Nigeria.
Keywords: Al2O3 Nanoparticles, Heavy Metals, Pharmaceutical Wastewater, Adsorption, Wastewater Treatment, Langmuir Isotherm, Pseudo-second-order Kinetics
Published date: 2026/06/30
