Green iron oxide particles for sustainable arsenic removal from water

Abstract

Arsenic sequestration from contaminated water using iron oxide particles (IOPs) is a promising green technology. Herein, iron oxide particles (IOPs) were prepared using an aqueous extract of locally available Melastoma malabathricum (MM) leaves and a ferric chloride hexahydrate (FeCl₃.₆H₂O) aqueous solution. Systematic characterization of the prepared IOPs was carried out by FTIR, XRD, SEM/EDX analysis, and pHpzc determination. FTIR spectrum of the IOPs showed a peak at 549 cm^-1 due to Fe-O stretching, while its XRD study indicated the amorphous nature of the synthesized IOPs. The EDX analysis confirmed the presence of Fe, O, and C atoms as major elements, and the point of zero charge (pHpzc) of the prepared material was found to be 6.98. The batch adsorption study showed the maximum As(V) adsorption of 93.03% at a pH value of 3. The experimental adsorption data of As(V) onto IOPs were best fitted with the Langmuir isotherm model, and the maximum adsorption capacity (qmax) was evaluated to be 103.63 mg/g. Further, the synthesized IOPs showed 70.11% arsenic removal from real ground water with 74.6 μg/L of arsenic concentration. The present study underscores the locally available plant’s leaves aqueous extract for the efficient production of low-cost, environmentally benign IOPs that have potential application in the remediation of arsenic contaminated water.