Dynamic adsorption of toxic indigo carmine dye on bio-inspired synthesised Fe₃O₄ nanoparticles: kinetic and thermodynamic study

ABSTRACT

The bio-inspired synthesis of Fe₃O₄ nanoparticles using a common kitchen waste, Bengal gram bean (Cicer arietinum L.) extract (BGBE) for enhanced adsorption of toxic indigo carmine dye is reported. Synthesised adsorbent was characterised by FTIR, FE-SEM, XRD, BET and XPS to understand its meticulous properties. The Fe₃O₄ adsorbent shows fascinating surface area of 78.61 m² g⁻¹ with a pore volume of 0.25 cc g⁻¹ at P/P₀ = 0.98 and displayed nanograin like morphology. The efficiency towards adsorption of toxic IC dye was found up to 99.71 ± 0.35% within 40 min at pH 7 with 0.25 g of Fe₃O₄ nanomaterials having the 299 ± 2 K surrounding temperature. The Langmuir monolayer adsorption capacity was found to 393.7 mg g⁻¹ at the stroke speed 150 rpm. The experimental data follows the Freundlich adsorption isotherm. Kinetically the uptake rate of IC dye follows pseudo-second-order kinetic model. The thermodynamic study reveals that IC dye adsorption process is spontaneous and endothermic in nature.

KEYWORDS:

• Bengal gram bean (Cicer arietinum L.) extract
• bio-inspired magnetic Fe₃O₄
• adsorption
• indigo carmine dye
• Freundlich isotherm

Acknowledgments

Authors are thankful to UGC-SAP and DST-FIST, DST-PURSE for financial support and instrument facilities at the Department of Chemistry, Shivaji University, Kolhapur. Author SAP is thankful for Golden Jubilee Research Fellowship, Shivaji University, Kolhapur (SU/CUDC/UGK/GJRF/2015-17/1503), and DAE-BRNS for Junior Research Fellowship (36(4)/14/31/2015/36002). This work was partly supported by the Human Resources Development Program (No. 20194030202470) of the Korea Institute of Energy Technology Evaluation and Planning (KETEP) Grant funded by the Korean Government Ministry of Trade, Industry and Energy and was partially supported by the Priority Research Centres Program through the NRF, Korea funded by the Ministry of Education, Science and Technology (2018R1A6A1A03024334).

Disclosure Statement

The authors have no conflict of interest.

Additional information

Funding

This work was supported by the Human Resources Development [No. 20194030202470].