RESUMO
The iron nanoparticles (Fe-NPs) have been synthesized using an environmentally friendly and simple green synthesis method. This study aims to obtain an aqueous extract from natural material wastes for synthesizing Fe-NPs. The produced Fe-NPs were evaluated as adsorbents for removing Pb, Se, Cu, Zn, and Cr from aqueous solutions. The formation of Fe-NPs was observed on exposure of the aqueous extract to the ferrous chloride and ferric chloride solutions. The characterization of the synthesized Fe-NPs was carried out using different instrumental techniques. As a function of the initial metal ion concentration, contact time, and various doses, the removal of the heavy metal ions was investigated. The UV-Vis spectrum of Fe-NPs showed a peak at 386 nm, 386 nm, 400 nm, 420 nm, 210 nm, 215 nm, and 272 nm of banana, pomegranate, opuntia, orange, potato, and onion, respectively. The FT-IR spectra confirmed the attachment of bioactive molecules from plants on the Fe-NPs surface. The effective reduction of metal ions was greatly aided by the -OH functional groups. The functional groups were examined and responsible for adsorption process by nanoparticle powder sample, these peaks are 3400 cm-1, 2900 cm-1, 1600 cm-1,1000 cm-1, and 1550 cm-1. The magnetization measurements revealed superparamagnetic behavior in the produced iron oxide nanoparticles. Heavy metal ions uptake followed a time, dose, and initial concentration-dependent profile, with maximum removal efficiency at 45 min, 0.4 g, and 3.0 mg/L of metal concentration, respectively.