Preparation of RGO and Anionic Polyacrylamide Composites for Removal of Pb(II) in Aqueous Solution.

Graphene oxide (GO) have been reported as adsorbent materials, because its surface contains a large number of oxygen-containing groups, which provide masses of active sites. Nevertheless, it is difficult to separate GO from aqueous solution by conventional means after the end of the adsorption process. Therefore, ethylene diamine-reduced graphene oxide/anionic polyacrylamide (E-RGO/APAM), with a large quantity of adsorption sites and strong flocculation was prepared in this study. The composite E-RGO/APAM was characterized by Fourier transform infrared (FTIR), laser Raman spectrometer (IR), scanning electron microscope (SEM). The obtained results indicated that amino groups were successfully introduced into GO. Particle size test showed that the particle size of E-RGO/APAM is up to three micrometers, which can be separated from the water by conventional means, such as filtration and centrifugation, to avoid secondary pollution. The efficiency of E-RGO/APAM for removing Pb(II) was tested. The results showed that the process of adsorption of Pb(II) by E-RGO/APAM can be fitted by pseudo second order kinetic equation, indicating that the adsorption rate of the adsorbent depends on the chemisorption process, and the theoretical maximum adsorption amount of E-RGO/APAM is 400.8 mg/g. Based on these results, it can be stated that E-RGO/APAM is effective in the removal of Pb(II) from aqueous solutions, and provides a new method for the removal of heavy metal ions from industrial wastewater.