Synthesis and Application of Polypyrrole/Fe 3 O 4 Nanosize Magnetic Adsorbent for Efficient Separation of Hg 2+ from Aqueous Solution

Abstract

In order to prepare the magnetic adsorbent, polymerization of pyrrole is performed in a mixture containing Fe 3 O 4 and FeCl 3 . FTIR, XRD, SEM, EDAX, BET and VSM techniques are employed to characterize the synthesized adsorbent. The results indicate that a homogeneous film of polypyrrole is formed on the surface of magnetic material. The synthesized adsorbent uptakes 173.16 mg g −1 of Hg 2+ from aqueous solution, which is superior to the previously reported results for a similar adsorbent. Magnetic performance of the adsorbent is sufficient to separate the used adsorbent from the solution by use of a magnetic bar placed outside of the vessel. Langmuir, Freundlich, Temkin, Redlich–Peterson, and Sips isotherm models are employed to evaluate the experimental adsorption data. The kinetic models are studied and the experimental data are described by the pseudo‐second‐order kinetic model. The calculated thermodynamic parameter shows that the sorption process is endothermic and spontaneous. Regeneration of the used adsorbent indicates that more than 90% of the initial capacity remains after regeneration.