Document Type : Research Paper
Department of Chemistry, Faculty of Science, Yazd University, Yazd, Iran
Department of Chemistry, Faculty of Science, Yazd University, Yazd, Iran. Central Iran Research Complex, Nuclear Science and Technology Research Institute, Yazd, Iran
Melia azedarach fruit extract is used to synthesize iron-polyphenol nanohydrogel and its capability as a flocculant in coagulation and removal of Disperse Yellow 211 dye from the aqueous solution is examined. The structure of iron-polyphenol nanohydrogel is studied by Fourier transform infrared spectroscopy, field emission scanning electron microscopy, X-ray diffraction, Brunauer-Emmett-Teller analysis, and zeta potential. The field emission scanning electron microscopy analysis indicates that in situ-cross-linking of polyphenols of Melia azedarach extract by ferric ions resulted in the formation of nanohydrogel containing particles in the range of 23-35 nm. Experiments confirmed that the prepared iron-polyphenol nanohydrogel has the excellent ability as the flocculant for coagulation and removal of the Disperse Yellow 211 dye in the pH range of 4.0-8.0, at room temperature. The required time for obtaining equilibrium at different concentrations of dye is ~ 50 minutes, and in this period, 200 mg L-1 of dye solution is 92% decolorized. The best-fitted model for experimental data is found to be the second-order kinetics and Langmuir thermodynamic indicating the sorption occurs in a monolayer and is governed by chemisorption. The maximum capacity of the sorbent is 1111.1 mg g-1.