Cu(II) adsorption of activated carbon fibers produced by radiation-induced graft polymerization

In this work, the adsorption behaviors of activated carbon fibers (ACFs) containing chelating functional groups were studied in heavy metal ion removal. The ACFs were modified by electron beam and glycidyl methacrylate (GMA, CH ₂-CCH₃COOCH₂CHOCH₂) graft polymerization in order to induce chelating functional groups, such as iminodiacetate (IDA, NH(CH₂COOH)₂) groups on the ACF surfaces. Fourier transform-infrared spectrometry (FT-IR) and X-ray photoelectron spectroscopy (XPS) were used to characterize the surface properties of the ACFs. The specific surface area and the pore structure were evaluated from nitrogen adsorption data at 77 K. The adsorbed amount of heavy metal ions was measured by using inductively coupled plasma-atomic emission spectrometer (ICP-AES). Results of FT-IR and XPS showed that the relative intensity of oxygen peaks increased with increasing the dose of electron beam. The results indicated that the radicals were increased as the dose of electron beam irradiation increased, and increased radicals led to the increase of the IDA groups. Also, the adsorption of heavy metal ions was increased by increasing the dose of electron beam irradiation. It was explained that the IDA groups of the treated ACF surfaces were introduced by radiation-induced graft polymerization and the increased IDA groups led to an increase of the adsorption of heavy metal ions.