Diverse Surface Chemistry of Cobalt Ferrite Nanoparticles to Optimize Copper(II) Removal from Aqueous Media

Abstract

Water pollution by heavy metals is one of the most serious worldwide environmental issues. With a focus on copper(II) ions and copper complex removal, in the present study, ultra-small primary CoFe2O4 magnetic nanoparticles (MNPs) coated with octadecylamine (ODA) of adequate magnetization were solvothermally prepared. The surface modification of the initial MNPs was adapted via three different chemical approaches based on amine and/or carboxylate functional groups: (i) the deposition of polyethylimide (PEI), (ii) covalent binding with diethylenetriaminepentaacetic acid (DTPA), and (iii) conjugation with both PEI and DTPA, respectively. FT-IR, TGA, and DLS measurements confirmed that PEI or/and DTPA were successfully functionalized. The percentage of the free amine (−NH2) groups was also estimated. Increased magnetization values were found in case of PEI and DTPA-modified MNPs that stemmed from the adsorbed amine or oxygen ligands. Comparative UV–Vis studies for copper(II) ion removal from aqueous solutions were conducted, and the effect of time on the adsorption capacity was analyzed. The PEI-modified particles exhibited the highest adsorption capacity (164.2 mg/g) for copper(II) ions and followed the pseudo-second-order kinetics, while the polynuclear copper(II) complex Cux(DTPA)y was also able to be immobilized. The nanoadsorbents were quickly isolated from the solution by magnetic separation and regenerated easily by acidic treatment.

Study of Kinetics and the Working Mechanism of Silica-Coated Amino-Functionalized CoFe2O4 Ferrite Nanoparticles to Treat Wastewater for Heavy Metals

“…Chemisorption is distinguished by its energy dependency on surface coverage and temperature, with activation energy often required due to strong intermolecular interactions between the adsorbate and the surface. The pseudo-second-order model generated a straight line that matched the data more correctly than the first-order model, which is in consonant with the results found in the previous investigation of Ren et al and Vamvakidis et al The maximal adsorption capacity based on the pseudo-second-order kinetic model is around 180.505 mg g –1 , which is much larger than the adsorption capacities obtained using the pristine adsorbent. The results indicate that the method used for Cu­(II) ion adsorption on the functionalized adsorbent is chemisorption.…”

“…On the basis of pseudo-models, Figure 9 displays a comparison plot of Cu(II) ion adsorption onto synthesized pristine and functionalized adsorbents. According to the work by Vamvakidis et al, 53 16.6 mg/g of Cu(II) ions adsorbed on the ferrite nanoparticles under equilibrium conditions. These calculations employed pseudo-first-order kinetics.…”

Fly Ash Coated with Magnetic Materials: Improved Adsorbent for Cu (II) Removal from Wastewater

“…Copper ions are one of the most widespread metals used in industry [ 3 ]. Among the three forms in which copper can be found, Cu 2+ is considered to be the most toxic [ 4 , 5 ], leading to negative impacts on human health and the environment [ 6 , 7 , 8 ]. The allowable limit of copper ions in drinking water was established by World Health Organization at 2 mg/L.…”

Dynamic remagnetisation of CoFe2O4 nanoparticles: thermal fluctuational thawing of anisotropy

“…Magnetic nanoparticles have great prospects for applications in various fields of engineering and technology. Their scope comprises both classical problems (the manufacture of permanent magnets [1,2] and catalysis [3,4]) and the development of novel cutting-edge techniques for ecology [5][6][7], biotechnology [8,9], and medicine (field-controlled drug delivery, magnetic hyperthermia, and cell surgery) [10][11][12][13]. * Author to whom any correspondence should be addressed.…”