Synthesis, characterization and application of steel waste-based iron oxide nanoparticles for removal of heavy metals from industrial wastewaters

Tumutungire Mwebembezi; Joel Wakatuntu; Joseph Jjagwe; Christopher Kanyesigye; Robinah N Kulabako; Peter Wilberforce Olupot

doi:10.1016/j.heliyon.2024.e28153

Synthesis, characterization and application of steel waste-based iron oxide nanoparticles for removal of heavy metals from industrial wastewaters

Heliyon. 2024 Mar 15;10(6):e28153. doi: 10.1016/j.heliyon.2024.e28153. eCollection 2024 Mar 30.

Authors

Tumutungire Mwebembezi¹, Joel Wakatuntu¹, Joseph Jjagwe¹, Christopher Kanyesigye², Robinah N Kulabako³, Peter Wilberforce Olupot¹

Affiliations

¹ Department of Mechanical Engineering, College of Engineering, Design, Art and Technology, Makerere University, P.O. Box 7062, Kampala-Uganda.
² National Water and Sewerage Corporation, Plot 3, Nakasero P.O BOX 7053 Kampala, Uganda.
³ Department of Civil and Environmental Engineering, College of Engineering, Design, Art and Technology, Makerere University, P.O. Box 7062, Kampala-Uganda.

Abstract

Water treatment and reuse can avail more clean and safe water for human use. In this study, iron oxide waste powder generated from the steel pickling process was used to develop iron oxide nanoparticles (IONPs) using solution gelation synthesis process. The powder and developed IONPs were characterized by X-ray fluorescence and diffraction (XRF, XRD), scanning electron microscopy, Fourier-transform infrared spectroscopy, and Brunauer-Emmett-Teller (BET) analyses. Adsorption experiments were carried out on synthetic water with lead and chromium metal ions. The adsorption data were analysed with Langmuir and Freundlich models. Adsorption kinetics were also analysed with Pseudo-First-Order and Pseudo-Second-Order models using non-linear regression. The synthesized IONPs were porous with active surface functional groups of hydroxyl bonds, with BET specific surface area of 325.02 m²/g. XRD results confirmed the cubic spinel structure of IONPs with particle sizes of 20-30 nm. The nanoparticles at a dosage of 0.35 g in 10 mL for 50 min effectively removed Pb(II) and Cr(VI) metal ions up to 99.9% from both synthetic water and industrial wastewater. The adsorption capacity (q_max) of IONPs was found to be 417 and 326.80 for Pb(II) and Cr(VI) respectively. Freundlich isotherm model data fitted best for the removal of both metal ions. The regression values for kinetic models confirmed that pseudo-second-order best fit the adsorption of both Pb(II) and Cr(VI) confirming chemisorption processes. This study contributes to elucidating alternative application of pickling waste from the steel rolling mills for the benefit of heavy metal removal in industrial wastewater.

Keywords: Heavy metals; Industrial wastewater treatment; Iron oxide nanoparticles; Nanoparticle synthesis; Steel pickling waste powder.