Functionalized Graphene Oxide/Polyacrylonitrile Nanofibrous Composite: Pb2+ and Cd2+ Cations Adsorption

In this research, graphene oxide (GO) was functionalized by tannic acid to produce GO-TA and fabricate a novel functionalized graphene oxide/ polyacrylonitrile (PAN) nanofibrous as an adsorbent in order to remove two hazardous heavy metals from aqueous solutions. The results showed that the composite adsorbent can properly adsorb Pb2+ and Cd2+ metal cations, due to having the numerous potential active sites. The synthesized materials were characterized by FTIR, SEM, XRD and atomic adsorption. Central composite design (CCD) and response surface methodology (RSM) were applied to analyze and model the obtained adsorption data. The applied variables were solution pH, nanoparticles weight percentage, metal ions concentration and contact time. The analysis of variance (ANOVA) showed that initial metal concentration and pH are the most main parameters for Pb(II) and Cd(II) ions adsorption. The optimum conditions were statistically and experimentally obtained for both heavy metals removal. The optimum conditions for 97.37% of Pb2+ and 94.28% of Cd2+ ions removal were meanly obtained at pH of 6.3, nanoparticles weight percentage of 4.26 wt.%, metal ions concentration of 35.74 ppm and contact time of 70.5 min. The maximum adsorption capacities were respectively found at 344.83 and 312.5 mg/g for lead and cadmium ions.