Magnetic MnxNi1-xFe2O4 nanoparticles for environmental remediation: Dye adsorption, adsorption mechanism, and recovery of the adsorbents

Title : Magnetic MnxNi1-xFe2O4 nanoparticles for environmental remediation: Dye adsorption, adsorption mechanism, and recovery of the adsorbents

Abstract:

Nano-structured spinel ferrites have been attractive for wastewater treatment to remove hazardous effluents. This study reports the adsorption of methylene blue (MB) dye by nanocrystalline spinel ferrites Mn_xNi_1-xFe₂O₄ (x = 0.0 to 1.0, step: 0.2) and recovery of the same nanoparticles used in the dye adsorption experiment. The nano ferrite powders were synthesized by the citrate-gel auto-combustion technique, which carries the advantage of quick preparation of ferrite powders at a much lower temperature (180°C-200°C) compared to the conventional ceramic method. X-ray diffraction (XRD) confirmed the formation of single-phased ‘fcc’ spinel ferrites. The pore structure and pore surface area of the synthesized ferrite nanoparticles were studied by BET analysis. The experiment was carried out for various time intervals using the ferrite samples for different concentrations i.e., 5, 10, 15, and 20 mg/L of MB dye. The UV-Vis. spectra were recorded by using the MB dye solutions for all concentrations to study the absorbance. It shows fast removal of dye during the first 30 minutes and thereafter it moderates or decreases very slowly. The maximum removal efficiency was observed at equilibrium time t = 35 minutes, which is a very effective dye removal property of prepared nano-structured Mn-Ni ferrites. Among all the tested samples, the highest adsorption efficiency was observed by x = 1.0 sample for 5 mg/L MB dye solution which is the excellent result of this experiment. Equilibrium isotherms were analyzed by Langmuir, Freundlich, and Tempkin isotherm models. The adsorption mechanism was studied by fitting the experimental data with the pseudo-first-order and pseudo-second-order kinetic models. After performing the experiment, the ferrite samples were recovered and characterized by XRD and FTIR, which are in good agreement with the used ferrite samples and the basic characteristics of nano-structured spinel ferrites. These nano ferrites can be used in environmental remediation like wastewater treatment for pollutant and toxic dyes due to their remarkable dye adsorption performance.

Biography:

Dr. Laxmi J. Hathiya is a materials scientist specializing in nano ferrites, with over 10 years of research experience. She recently completed her postdoctoral fellowship at CHARUSAT University, India, where she worked on rare-earth ion-substituted Mn-Zn ferrite-based fluids for hyperthermia applications. She earned her Ph.D. in Physics from Saurashtra University in 2023. Her doctoral work was on “Synthesis and characterization of nano-structured ferrites with reference to special applications” and she also attained the best thesis award. She is awarded with a national fellowship by UGC – Statutory body of the government of India and she has worked as a JRF and SRF at the Department of Physics, Saurashtra University under this fellowship. Prior to this, she was a lecturer of Physics at VVP Engineering College, Rajkot India. She Received her M.Sc. (Physics) from Saurashtra University in 2014. The career objective of the speaker is to work in the field of nano ferrites with reference to their applications. She has presented her research work at many national and international conferences and achieved the best presentation awards. She has published research papers in peer-reviewed journals and conference proceedings. She has also published book chapters and a patent. She serves as a reviewer for six SCI-indexed journals.