Rapid removal of heavy metal cations and anions from aqueous solutions by an amino-functionalized magnetic nano-adsorbent

• Published in: Journal of hazardous materials Vol. 163; no. 1; pp. 174 - 179
• Main Authors: Huang, Shih-Hung, Chen, Dong-Hwang
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 15.04.2009; Elsevier
• Subjects: Adsorption; Amines - chemistry; Amino-functionalization; Anions; Applied sciences; Atmospheric pollution; Cations; Chemical engineering; Exact sciences and technology; Heavy metal ions; Ion exchange; Magnetic nano-adsorbent; Magnetics - methods; Metal Nanoparticles - chemistry; Metal Nanoparticles - ultrastructure; Metals, Heavy - chemistry; Metals, Heavy - isolation & purification; Microscopy, Electron, Transmission; Molecular Structure; Particle Size; Pollution; Polyamines; Solutions; Spectroscopy, Fourier Transform Infrared; Time Factors; Water Pollutants, Chemical - chemistry; Water Pollutants, Chemical - isolation & purification; Heavy metal ions; Adsorption; Magnetic nano-adsorbent; Amino-functionalization; Nanoparticle; Phase change; Saturation; Adsorption isotherm; Adsorption capacity; Metal ion; Activation; Ultrafine particle; X ray diffraction; Langmuir isotherm; Heavy metal; Transmission electron microscopy; Functionalization; Isoelectric point; Aerosols; Air pollution; Electrokinetic potential; Aqueous solution; Fourier-transformed infrared spectrometry; Ion exchange
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2008.06.075

A novel magnetic nano-adsorbent has been developed by the covalent binding of polyacrylic acid (PAA) on the surface of Fe 3O 4 nanoparticles and the followed amino-functionalization using diethylenetriamine (DETA) via carbodiimide activation. Transmission electron microscopy image showed that the amino-functionalized Fe 3O 4 nanoparticles were quite fine with a mean diameter of 11.2 ± 2.8 nm. X-ray diffraction analysis indicated that the binding process did not result in the phase change of Fe 3O 4. Magnetic measurement revealed they were nearly superparamagnetic with a saturation magnetization of 63.2 emu/g Fe 3O 4. The binding of DETA on the PAA-coated Fe 3O 4 nanoparticles was demonstrated by the analyses of Fourier transform infrared (FTIR) spectroscopy and zeta potential. After amino-functionalization, the isoelectric point of PAA-coated Fe 3O 4 nanoparticles shifted from 2.64 to 4.59. The amino-functionalized magnetic nano-adsorbent shows a quite good capability for the rapid and efficient adsorption of metal cations and anions from aqueous solutions via the chelation or ion exchange mechanisms. The studies on the adsorption of Cu(II) and Cr(VI) ions revealed that both obeyed the Langmuir isotherm equation. The maximum adsorption capacities and Langmuir adsorption constants were 12.43 mg/g and 0.06 L/mg for Cu(II) ions and 11.24 mg/g and 0.0165 L/mg for Cr(VI) ions, respectively.