Purpose: Dyes are highly toxic coloured compounds in nature that are largely applied in paper, food, textile and printing industries. Here, the adsorption technique was performed to remove methyl orange (MO) dye from water by polyethylene glycol (PEG) modified iron oxide nanoparticles (Fe3O4 NPs).
Methods: The method used for Fe3O4 NPs synthesis was chemical precipitation. The particles were analyzed by transmission electron microscope, magnetometer, BET analyzer, fourier-transform infrared spectroscopy, X-ray powder diffraction, zetasizer and particle size analyzer. The influence of pH (4.0 to 10.0), NaCl concentration (0.01 mM to 2 M), adsorbent dosage (1 to 10 mg), and the role of surface charge on adsorptive removal were investigated.
Results: The NPs size, zeta potential and surface area was found to be 26 ± 1.26 nm, 33.12 ± 1.01 mV and 119 m2/g respectively. The adsorption of MO on Fe3O4 NPs agreed best to Freundlich model (R2 = 0.965) when compared with Langmuir model (R2 = 0.249). By comparing pseudo-first-order kinetic model (R2 = 0.937), kinetic adsorption study was better followed by pseudo-second-order kinetic model (R2 = 1). The adsorption rate decreased with increasing NaCl concentration. At pH 4, maximum adsorption was noted. The particles were also exhibited excellent antibacterial and antibiofilm activities. The ROS formation, lipid peroxidation and oxidative stress were increased with increase in NPs concentration. The NPs precoated slides exhibited more than 50% growth inhibition.
Conclusion: The investigation denotes the versatile applications of the prepared particles for removing the dye stuffs from industrial effluents and as antibacterial and antibiofilm agent.
Keywords: Adsorption; Antimicrobial activity; Iron oxide particles; Methyl orange dye.
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