Cytotoxicity, Removal of Congo Red Dye in Aqueous Solution Using Synthesized Amorphous Iron Oxide Nanoparticles from Incense Sticks Ash Waste

Magnetic nanoparticles have gained huge importance in the last ten years. They have found tremendous applications in the field of medicine, electronics, and environmental cleanup. The synthesis of amorphous iron oxide nanoparticles (AIONPs) is expensive making its applications highly overpriced. This research study reports the synthesis of AIONPs from waste incense sticks ash (ISA) in two steps. The first step is the recovery of ferrous fractions from ISA, followed by concentrated HCl treatment of magnetic fraction along with ultrasonication. And the second step includes treatment of ferrous-rich leachate with sodium hydroxides. The size of synthesized AIONPs varied from 40-90 nm and were highly aggregated due to the formation of large clumps. Cytotoxicity of synthesized AIONPs was determined on a normal human lung (BEAS-2B) cell line by using an MTT assay. Data showed that AIONPs induced cell toxicity in a dose-dependent manner. The particles were mainly spherical to rod-shaped and highly aggregated, it was confirmed by the microscopy analysis. The Fourier transform infrared (FT-IR) and Raman spectroscopy revealed the Fe-O, Si-O-Al as major functional groups in the AIONPs, while X-ray diffraction (XRD) revealed the amorphicity and physical property measurement system (PPMS) revealed the magnetic strength of the synthesized AIONPs. Finally, the AIONPs particles were applied for the remediation of Congo red dye from the wastewater by the adsorption method, and about 72% removal was achieved after one hour. The utilization of such ISA waste, for the synthesis of value-added minerals and their utilization for environmental cleanup, makes this whole process cost-efficient and environment-friendly.