Polyethylene glycol modified magnetic nanoparticles for removal of heavy metal ions from aqueous solutions

Polyethylene glycol (PEG) modified magnetic nanoparticles with low toxicity and good biocompatibility were fabricated as the adsorbent for removal of Cr(VI), Cu(II), and Pb(II) from aqueous solution. These nanocomposites were characterized by TEM, VSM, XRD, TGA, and FTIR. The adsorption capacity, kinetics, acid resistance, and the key factors affecting the adsorption process were evaluated for the adsorbent in a batch mode. The characterization results demonstrated that the magnetic nanocomposite with 3.6% PEG modification was successfully prepared. According to the Langmuir model, the maximal saturated adsorption capacity of Cr(VI), Pb(II), and Cu(II) on the adsorbent at pH 7.0 were 15.07 mg/g, 21.27 mg/g, and 41.0 mg/g, respectively. The adsorption followed pseudo-second-order kinetics with fast speed, and was highly dependent on pH. The acid resistance performance of magnetic nanoparticles was obviously improved by PEG modification on its surface, and this adsorbent showed good reusability for heavy metals. The obtained adsorbent with good performance has a potential application for removal of heavy metals from water.