Green Production Adsorption Effect of Iron Oxide Nanoparticles for Chromium(Vi) Ion in Wastewater

Abstract

Due to its high toxicity, the elimination of Cr(VI) in polluted and wastewater by conventional methods is both costly and complex. In this study, iron oxide nanoparticles (GT-FeONPs) were prepared using Globularia trichosantha flower extract as an environmentally friendly, low-cost method to remove chromium ions from aqueous media. The characteristic properties of the synthesized GT-FeONPs were researched by UV-Vis, FT-IR, TEM and XRD techniques, followed by sequential experiments to remove Cr(VI) from aqueous solutions. In this context, the optimum initial pH, optimum concentration and optimum temperature values were determined. FT-IR spectrum analysis revealed that GT-FeONPs were covered by plant components and XRD analysis revealed that the crystals had an average size of 14.34 nm. TEM analysis revealed that the particles were spherical and nanostructured with an average size of 10.89 nm. When optimum adsorption conditions were provided, the highest removal efficiency was realized at pH 2.0. At temperatures higher than 40 °C, the removal rate decreased. Absorption measurements using UV–vis spectrophotometer with different amounts of adsorbent showed that the highest removal rate of Cr(VI) was 88.30 % and the highest removal rate for reuse was 91.5 %. When the adsorption data were applied to both Langmuir and Freundlich isotherm models, it was found that the Langmuir model was more powerful in showing the equilibrium form of Cr(VI) adsorption. The kinetic model that best explained the adsorption rate mechanism was determined to be the Pseudo Second Order Kinetic model. This study shows that FeONPs synthesized under the activity of Globularia trichosantha flower extract can be utilized as adsorbents to remove Cr(VI) ions from wastewater. © 2025