Iron oxide nanoparticle-assisted arsenic removal from aqueous system

Area of Science:

• Environmental Science
• Materials Science
• Nanotechnology

Background:

• Arsenite [As(III)] is a highly toxic and mobile contaminant prevalent in groundwater.
• Iron oxide nanoparticles (IONPs) show potential for heavy metal remediation.

Purpose of the Study:

• To synthesize IONPs for effective removal of As(III) from contaminated water.
• To characterize the synthesized IONPs and evaluate their adsorption performance.

Main Methods:

• IONPs synthesized via a chemical method using iron cations (Fe3+) and polyvinyl alcohol (PVA).
• Characterization using X-ray diffraction (XRD) and transmission electron microscopy (TEM).
• Adsorption experiments conducted to determine As(III) removal efficiency and isotherm studies.

Main Results:

• XRD confirmed a single-phase rhombohedral crystal structure (R3c space group).
• TEM revealed IONPs with an average size of 45 nm and a rhombohedral shape.
• Maximum As(III) adsorption capacity reached 96% using 2.0 gL(-1) IONPs at pH 4.5-7.5.
• Langmuir isotherm provided a better fit than Freundlich for adsorption studies.

Conclusions:

• Synthesized IONPs are effective in removing As(III) from water.
• Adsorption mechanism involves As(III) binding to IONPs followed by surface hydrolysis of iron species.
• IONPs present a viable nanomaterial for arsenic remediation in contaminated water sources.