Removal of Hg (II) from aqueous solution using polypyrrole/SBA-15 nanocomposite: Experimental and modeling

A nanocomposite of polypyrrole (PPy)/SBA-15 was synthesized, characterized and used for Hg (II) adsorption from aqueous medium. The adsorbent characterization was carried out using Fourier transform infrared spectra (FT-IR), X-ray diffraction (XRD), N-2 adsorption/desorption, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Atomic absorption spectrophotometer (AAS) was also applied to determine the amount of Hg (II) ion in the solution. Effective parameters on Hg (II) removal such as pH, the amount of adsorbent and contact time were examined and optimized at temperatures ranging from 25 to 45 degrees C. Optimum values were pH 8, contact time of 60 min and the amount of absorbent of 1 g/l. The Langmuir and Freundlich adsorption isotherm models were applied and the presented results show very good agreement with Langmuir adsorption isotherm with high adsorption capacity of 200 mg/g. In addition, pseudo-second order kinetic equation was best fitted for adsorption kinetic model. The adsorption process data verified its spontaneous and endothermic nature. (C) 2015 Elsevier B.V. All rights reserved.