Hexavalent chromium removal from aqueous solutions using biogenic iron nanoparticles: Kinetics and equilibrium study

Area of Science:

• Environmental Science
• Materials Science
• Nanotechnology

Background:

• Hexavalent chromium (Cr (VI)) poses a significant threat to aquatic ecosystems and human health.
• Conventional methods for Cr (VI) removal are often costly and inefficient.
• Developing sustainable and effective nanomaterials for pollutant removal is crucial.

Purpose of the Study:

• To synthesize iron oxide nanoparticles using Rosa indica flower petal extract (RIFP-FeONPs).
• To characterize the synthesized RIFP-FeONPs using various analytical techniques.
• To evaluate the efficiency of RIFP-FeONPs in removing Cr (VI) from aqueous solutions.

Main Methods:

• Green synthesis of RIFP-FeONPs using Rosa indica flower petal extract.
• Characterization using UV-Visible Spectroscopy, FTIR, SEM, EDX, XRD, Zeta potential, and DLS.
• Adsorption studies to assess Cr (VI) removal efficiency.
• Analysis using adsorption isotherm and kinetic models (Langmuir, Freundlich, pseudo-first order).

Main Results:

• RIFP-FeONPs exhibited surface plasmon resonance at 269 nm, indicating Fe3+ presence.
• XRD confirmed the face-centered cubic structure of pure iron nanoparticles.
• Particles were spherical, polydisperse, with a size range of 70-120 nm (average 115.5 ± 29 nm).
• High Cr (VI) removal efficiency was observed, fitting well with Langmuir and Freundlich isotherms (R² = 0.98).

Conclusions:

• RIFP-FeONPs are effectively synthesized via a green route.
• The synthesized nanoparticles demonstrate significant potential for hexavalent chromium removal.
• RIFP-FeONPs represent a promising and sustainable nanosorbent for industrial wastewater treatment.