| Autor: |
ul Haq Zia, Tanveer, Qureshi, Muhammad Hassaan, Ara, Behisht, Gul, Kashif, Ghazali, Daud Khan |
| Předmět: |
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| Zdroj: |
Desalination & Water Treatment; Aug2022, Vol. 268, p67-88, 22p |
| Abstrakt: |
Zn(II) ion-imprinted polymer [Zn(II) IIP] was prepared by following precipitation polymerization using acrylonitrile as functional monomer, N,N’-Methylenebis(acrylamide) as cross-linker and potassium persulfate as thermal initiator. Furthermore, 8-hydroxyquinoline was used as complexing agent for Zn(II) ions that was also employed for functionalizing the Zn(II) IIP. After the leaching of the Zn(II) ions, an ion-imprinted polymer [Zn(II) IIP] was obtained which showed high tendency of selective recombination with the Zn(II) ions. The equilibrium and kinetic adsorption studies of Zn(II) ions on both Zn(II) IIP and non-imprinted polymer (NIP) were carried out at different temperatures. Scanning electron microscopy and Fourier-transform infrared spectroscopy was carried out for evaluating the morphology and the various functional groups present in the molecular structure. The specific surface area was determined to be 337.30 m² g–1 for NIP whereas 439.54 m² g–1 for Zn(II) IIP by applying the Brunauer–Emmett–Teller model to the nitrogen adsorption isotherm. Similarly, the pore-size distribution was analyzed using the Barrett–Joyner–Halenda model and t-plot method confirming the surface texture of both adsorbent to be mesoporous in nature. The isotherm models of Langmuir, Freundlich, and Dubinin–Radushkevich were used to analyze the adsorption equilibrium data. It was revealed that the adsorbents surface has heterogeneous nature as Freundlich isotherm was more closely followed by the adsorbents. The maximum adsorption capacity was found to be 3.75 mg g–1 for NIP whereas 6.82 mg g–1 for Zn(II) IIP. The relative selectivity coefficient K’ for Zn(II)/Co(II), Zn(II)/Cu(II), Zn(II)/Ni(II) and Zn(II)/Pb(II) metal ion pairs is determined to be 24.827, 1.273, 3.931 and 2.437, respectively. The adsorption kinetic data followed pseudo-first-order model with respect to R² values suggesting physical nature of adsorption. Electrokinetic study was also performed for understanding the nature of interaction between adsorbate and adsorbent which was validated on the basis of Grahame and pK-1 model depicting the surface electrostatic potential nature of charges. Van’t Hoff plot was employed on the thermodynamic data of adsorption for attaining the change in entropy (ΔS) and enthalpy (ΔH), in addition to the Gibb’s free (ΔG) change as well. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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