Surface engineered magnetic nanoparticles for removal of toxic metal ions and bacterial pathogens

• Published in: Journal of hazardous materials Vol. 192; no. 3; pp. 1539 - 1547
• Main Authors: Singh, Sarika, Barick, K.C., Bahadur, D.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 15.09.2011; Elsevier
• Subjects: Adsorption; Applied sciences; arsenic; Atmospheric pollution; Bacteria; Bacterial pathogens; cadmium; Chemical engineering; chromium; cobalt; copper; electrostatic interactions; Escherichia coli; Escherichia coli - metabolism; Ethylenediamines - chemistry; Exact sciences and technology; Ferric Compounds - chemistry; Fourier transform infrared spectroscopy; General purification processes; Ion exchange; Ions; iron oxides; lead; Magnetic; Magnetics; Metal ions; Metals - chemistry; Microscopy, Electron, Transmission - methods; Nanocomposites; Nanomaterials; Nanoparticles; Nanoparticles - chemistry; Nanostructure; nickel; pathogens; Pollution; Spectroscopy, Fourier Transform Infrared - methods; Static Electricity; Succimer - chemistry; Succinates - chemistry; succinic acid; Surface functionalization; Surface Properties; temperature; thiols; Toxic; Toxic metal ions; toxicity; Toxicology; transmission electron microscopy; Waste-water; Wastewaters; Water Microbiology; Water Pollutants, Chemical - analysis; Water Purification - methods; Water treatment and pollution; X-Ray Diffraction; zeta potential; Nanoparticles; Surface functionalization; Waste-water; Magnetic; Toxic metal ions; Bacterial pathogens; Elementary analysis; Chemical analysis; Microbiology; Nanoparticle; Escherichia coli; Metal ion; Ultrafine particle; Waste water; Functionalization; Pathogenic; Bacteria; Electrokinetic potential; Ion exchange; Biological contamination; Enterobacteriaceae; Thiol; Electrostatic interaction; Nanostructure; Arsenites; Transmission electron microscopy; Aerosols; Air pollution
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2011.06.074

[Display omitted] ► Removal of multiple toxic metal ions (Cr 3+, Co 2+, Ni 2+, Cu 2+, Cd 2+, Pb 2+ and As 3+) and bacterial pathogens ( E. coli) from water. ► Role of surface functionality (COOH, NH 2 or SH) on adsorption mechanism of toxic metal ions. ► Field dependent magnetic responsivity and reusability of nanoadsorbents for water purification. Surface engineered magnetic nanoparticles (Fe 3O 4) were synthesized by facile soft-chemical approaches. XRD and TEM analyses reveal the formation of single-phase Fe 3O 4 inverse spinel nanostructures. The functionalization of Fe 3O 4 nanoparticles with carboxyl (succinic acid), amine (ethylenediamine) and thiol (2,3-dimercaptosuccinic acid) were evident from FTIR spectra, elemental analysis and zeta-potential measurements. From TEM micrographs, it has been observed that nanoparticles of average sizes about 10 and 6 nm are formed in carboxyl and thiol functionalized Fe 3O 4, respectively. However, each amine functionalized Fe 3O 4 is of size ∼40 nm comprising numerous nanoparticles of average diameter 6 nm. These nanoparticles show superparamagnetic behavior at room temperature with strong field dependent magnetic responsivity. We have explored the efficiency of these nanoparticles for removal of toxic metal ions (Cr 3+, Co 2+, Ni 2+, Cu 2+, Cd 2+, Pb 2+ and As 3+) and bacterial pathogens ( Escherichia coli) from water. Depending upon the surface functionality (COOH, NH 2 or SH), magnetic nanoadsorbents capture metal ions either by forming chelate complexes or ion exchange process or electrostatic interaction. It has been observed that the capture efficiency of bacteria is strongly dependent on the concentration of nanoadsorbents and their inoculation time. Furthermore, these nanoadsorbents can be used as highly efficient separable and reusable materials for removal of toxic metal ions.