Covalently modified magnetite nanoparticles with PEG: preparation and characterization as nano-adsorbent for removal of lead from wastewater

Background: Lead is one of the hazardous materials which is associated with pollution and toxicity problems. This paper describes a novel approach for removal of lead from wastewater. Although naked magnetic nanoparticles have been applied for removal of different pollutants from wastewater, there was no research on employment of covalently PEG modified magnetic nanoparticles for such purpose. Results: A magnetic nano-adsorbent was prepared by chemically modification of magnetite nanoparticles (MNPs) with polyethylene glycol (PEG) for removal of lead ions. The surface of MNPs was coated covalently with 3-aminopropyltriethoxysilane (APTES) and PEG. Modified MNPs (MNPs-APTES-PEG) were characterized by FT-IR, XRD, SEM, and particle size analysis. Compared to the oleic acid coated MNPs, MNPs-APTES-PEG exhibited significant higher uptake capability for Pb(II) ions. The effective parameters on the extent of adsorption (time, temperature, Pb(II) concentration, contact time and pH) were studied and optimized by response surface methodology. Maximum uptake of MNPs-APTES-PEG for Pb(II) was determined to be 81.39 ± 2.5%. The results showed that the kinetic data was best described by Pseudo-second order model as evidenced by the relatively high value of determination coefficient (R2 = 0.9998). Successful removal of Pb(II) from industrial wastewater was also accomplished by MNPs-APTES-PEG. Conclusions: The results revealed high capability and excellent efficiency of developed nano-adsorbents in removal of lead contaminants from industrial wastewater.