Environmental water remediation using covalently functionalized zerovalent iron nanocomposites with 2-pyridinecarboxaldehyde via 3-aminopropyltrimethoxysilane and ethylenediamine

ABSTRACT

The adsorption technology involving nano zerovalent iron (NZVI) has been widely employed to remediate polluted water based on a number of economic aspects. However, this technology is facing a high challenge in the removal process of pollutants due to hydrolysis and stability characteristics of zerovalent iron. Therefore, this study is aimed to demonstrate a method for encapsulation and functionalization of NZVI nanoparticles with 3-aminopropyltrimethoxysilane (NH₂) and 2-pyridinecarboxaldehyde (PY), respectively to produce the target nanocomposite (NZVI-NH₂-PY). Zerovalent iron nanoparticles are also aimed to functionalize with ethylenediamine (ED) and 2-pyridine carboxaldehyde to produce NZVI-ED-PY nanocomposite. The TEM images showed that the sizes of NZVI-NH₂-PY and NZVI-ED-PY nanocomposites are in the range 3.33–4.35 and 5.42–10.36 nm, respectively. More characterization evidences were concluded by thermal gravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD). The two novel magnetic nanocomposites have been used for removal of Co(II), Zn(II), Pb(II), Cd(II), Hg(II), Cu(II) beside radioactive isotopes (⁶⁵Zn and ⁶⁰Co) from water. NZVI-NH₂-PY nanocomposite was more selective toward Hg(II), Pb(II) and Cd(II), while NZVI-ED-PY was more selective toward Z(II), Co(II) and Co(II). Different kinetic models were applied and the investigated metal ions were characterized to undergo the pseudo-second order using both NZVI-NH₂-PY and NZVI-ED-PY nanocomposites.

KEYWORDS:

• Zerovalent iron
• ethylenediamine
• 3-aminopropyltrim-ethoxysilane
• 2-pyridenecarboxaldehyde
• adsorption