EDTA-Functionalized Magnetic Graphene Oxide/Polyacrylamide Grafted Carboxymethyl Cellulose Hydrogel for Removal of Pb+2 from Aqueous Solution

A promising sorbent was prepared by a combination of different eco-friendly functional groups such as ethylenediaminetetraacetic acid with 3-aminopropyltriethoxysilane (EDTA/Si) and polyacrylamide grafted carboxymethyl cellulose (AmCMC) with magnetic graphene oxide (mGO) and N,N-Methylene bis-acrylamide as a crosslinker for efficient removal of lead ions (Pb2+) from aqueous solutions. The prepared sorbent was characterized by X-ray diffraction (XRD), infrared spectroscopy (FTIR), thermal gravimetric analysis (TGA), the scanning electron microscope (SEM), Vibrating sample magnetometer (VSM), and Zeta-potential measurements. The oxidation of graphite was confirmed by XRD and transmission electron microscope (TEM). The adsorption conditions such as contact time, pH, sorbent dosage, and initial Pb2+ concentrations were investigated to optimize the adsorption efficiency of the prepared sorbent. EDTA/Si/mGO/AmCMC was found to be an ideal sorbent for Pb2+ removal with a higher adsorption capacity due to the successive link of chelating groups onto AmCMC. From the data, at pH = 5.3 after 120 min, EDTA/Si/mGO/AmCMC has high removal efficiency of Pb2+ (92%) compared with AmCMC (46%). For deep information, Kinetic and isotherm models were applied for the adsorption process. From the data, the harmony of data fitting with the pseudo-second-order kinetic model and the Langmuir isotherm model. According to the Langmuir adsorption isotherms, the maximum adsorption capacity of 0.15 g EDTA/Si/mGO/AmCMC at pH = 5.3 after 120 min is 86 mg/g.