Fabrication and characterization of high-branched recyclable PAMAM dendrimer polymers on the modified magnetic nanoparticles for removing naphthalene from aqueous solutions

Abstract

In this study, magnetic nanoparticles (MNPs) modified with poly amidoamine (PAMAM) dendrimers - by adding methyl acrylate and ethylenediamine continuously till 10th generation- which further anchored to benzaldehyde ligand through polymeric bonding and studied as a novel method for synthesizing a nano sorbent for removing naphthalene (NAP) from aqueous environments. Synthesized nanopolymer was characterized by Fourier transform infrared spectroscopy (FTIR), Field-Emission Scanning Electron Microscopy (FE-SEM) equipped with EDS, X-ray Diffraction (XRD), Vibrating Sample Magnetometry (VSM), thermal gravimetric analysis (TGA). Based on the obtained analysis results synthesized average nanocomposite diameter is 25–55 nm. In batch experiments, operative parameters in adsorption process like pH, sorbent dosage, contact time and initial concentration of NAP have investigated, and maximum adsorption for NAP by sorbent in optimal adsorption conditions examined. Therefore, synthesized nanocomposite used for removing NAP from real water samples and industrial wastewater containing complex matrices and all of them analyzed by Gas Chromatography-Mass spectrometry (GC-MS). The NAP removal efficiency of 93–100% obtained from water in the river, sea and industrial waste. Also, fitting the adsorption process with various isotherm models and kinetic studies designated that the equilibrium data follow from the Langmuir model (R2 = 0.9957) and adsorption kinetic from the pseudo-second-order model (R2 = 0.9999). Maximum adsorption capacity for sorbent was qmax = 101 mg g−1. As a result, synthesized magnetic dendrimers have high adsorption capacity without no environmental pH adjustment which is recyclable for four-times as an efficient sorbent used for removing NAP from aqueous solutions.