- 1National Yunlin University of Science and Technology, Department of Safety, Health, and Environmental Engineering, Yunlin, Taiwan (cefi63214@gmail.com)
- 2Research Centre for Soil & Water Resources and Natural Disaster Prevention (SWAN), National Yunlin University of Science and Technology, Douliou, Yunlin 64002, Taiwan (R.O.C.)
- 3Department and Graduate School of Safety Health and Environmental Engineering, National Yunlin University of Science and Technology, 123, Section 3, University Road, Douliou, Yunlin 64002, Taiwan (R.O.C.)
Amaranth (AM) is a typical anionic azo dye, which has been applied in cosmetics, wood, paper, synthetic fiber, food additives, leather, and artificial dyeing, poses significant risks to both human health and the environment. Therefore, its removal from water is essential to safeguard public health and ensure a sustainable ecosystem. In this work, a novel magnetic Fe3O4@LPP was successfully synthesized via a co-precipitation method and applied for the removal of AM dye from an aqueous environment. Several characterization techniques, including point of zero charge (pHPZC), N2 adsorption/desorption, Energy dispersive X-ray spectroscopy (EDS), Field emission scanning electron microscopy (FE-SEM), Vibrating sample magnetometer (VSM), Fourier transform infrared spectroscopy (FTIR), Transmission electron microscopy (TEM) and X-ray diffractometer (XRD), were analyzed to reveal the functional and structural properties of the as-synthesized Fe3O4@LPP composite. AM dye adsorption performances were tested as a function of the operational conditions, such as stirring speed (50-300 rpm), temperature (25-55 oC), initial pH solution (2-10), Fe3O4@LPP dosage (0.01 to 0.08 g/30 mL), contact duration (0-180 minutes), and initial AM dye concentration (50-500 mg/L) in a batch mode of operation. Kinetic analysis revealed that the sorption process followed the pseudo-1st-order kinetic model across all initial concentrations, showing strong correlation between the experimental data and the model predications. Furthermore, the equilibrium sorption data were best fitted by the Langmuir isotherm model, suggesting monolayer sorption on a homogeneous surface, with a maximal adsorption uptake of 445.5±19.6 mg g-1. The thermodynamic analysis of AM dye adsorption indicated that the process was endothermic, feasible, and spontaneous. Various eluting agents were evaluated in the desorption studies, and 0.1 M NaOH exhibited the greater desorption efficiency of 89.4%. Overall, the outcomes of this study confirm that Fe3O4@LPP composite is a promising and effective adsorbent for the remove of dyestuff from wastewater.
Keywords: Removal, Amaranth, Iron oxide, Lychee peel, Desorption.
How to cite: Hsu, J.-Y., Munagapati, V. S., and Wen, J.-C.: Adsorptive removal of an anionic Amaranth dye from aqueous solution using magnetic iron oxide-loaded lychee peel powder (Fe3O4@LPP): Isotherm, kinetic, thermodynamic and desorption studies, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-9232, https://doi.org/10.5194/egusphere-egu26-9232, 2026.
