Facile additive-free synthesis of hematite nanoparticles for enhanced adsorption of hexavalent chromium from aqueous media: Kinetic, isotherm, and thermodynamic study

ABSTRACT

Facile additive-free synthesis of hematite nanoparticles via a chemical co-precipitation technique is reported for adsorptive removal of Cr(VI) from aqueous media, and adsorption capacity as much as 43.05 mg/g at solution pH 2.0 is observed. Langmuir isotherm model was fitted nicely with adsorption experimental data, whereas kinetic studies reveal that both surface adsorption and intra-particle diffusion are involved in the adsorption mechanism. Thermodynamic studies established the favorability, spontaneity, and exothermic nature of the adsorption process. Regeneration studies revealed the stability of the adsorbent up to three consecutive cycles, indicating it as a potential adsorbent for Cr(VI)-contaminated wastewater remediation.

KEYWORDS:

• Iron oxide
• adsorption
• hexavalent chromium
• water treatment
• nanoparticle

Acknowledgment

The authors acknowledge the CRF facility of NIT Agartala for FESEM measurements.

Funding

B. Saha acknowledges the Department of Science and Technology (DST), Government of India, for financial support (Grants order No. SERB/F/7430/2013-14) under Fast Track Young Scientist award scheme.