In this research, a magnetic core-shell catalyst support was prepared by polymerization of pyrrole in the The enhancing effect of H 2 O 2 and the inhibition effects of some reagents on the degradation efficiency were studied. The photodegradation products were identified by GC-MS technique.

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.

This research was aimed to prepare a magnetically photocatalyst enabling to degrade pharmaceutical wastewater and detoxification of pollutant such as naproxen, by visible light irradiation. The nano-sized NiS and NiO photocatalysts exhibit higher reactivity than their microsized counterparts, but separation of the used photocatalyst from the degradation solution is hard and imperfect. To remove this difficulty, magnetic polypyrrole core-shell (Fe O @PPY) was synthesized and employed as catalyst support. The magnetization property of the synthesized photocatalysts measured by VSM technique indicated that the photocatalysts were sufficiently magnetized to be readily separated from degradation solution by use of external magnetic field. The DRS study showed that the band gap of the photocatalysts shifted to lower energy after immobilization on the support materials leading to higher degradation efficiency. The optimal efficiency was obtained with the catalysts loaded with 50% of NiO and 50% of NiS. The augmenting effect of H O and the inhibition influence of some organic and inorganic compounds on the degradation process were studied. Regeneration of the used photocatalyst was performed by heat treatment, and the catalyst treated at 400°C retained most of its initial capacity. The degradation capacity was kinetically fast, and the equilibrium was attained within 30 min.

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In this research, multiwall carbon nanotube was magnetized and subsequently functionalized by thiosemicarbazide. After characterization by FTIR, BET, SEM, EDAX, and VSM techniques, the magnetized adsorbent (multi-walled carbon nanotubes (MWCNTs)/FeO) was used for removal of Hg from aqueous solutions and the experimental conditions were optimized. The adsorption capacity of 172.83 mg g was obtained at 25 °C and pH = 3 which was superior to the value obtained for initial multiwall carbon nanotube, magnetized sample, and many previously reported values. In the presence of Pb and Cd, the adsorbent was selective towards mercury when their concentration was respectively below 50 and 100 mg L. The adsorption process was kinetically fast and the equilibration was attained within 60 min with 69.5% of the capacity obtained within 10 min. The used adsorbent was regenerated by HNO solution, and the regenerated adsorbent retained 92% of its initial capacity. The magnetic sensitivity of the adsorbent allowed the simple separation of the used adsorbent from the solution by implying an appropriate external magnetic field. The adsorption data was well fitted to the Langmuir isotherm model, indicating homogeneous and monolayer adsorption of mercury by the adsorbent.