Document Details
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Document Type |
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Thesis |
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Document Title |
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"REMOVAL OF SOME HEAVY METALS FROM GROUNDWATER USING MODIFIED SILICA NANOCOMPOSITES إزالة بعض المعادن الثقيلة من المياه الجوفية باستخدام متراكبات من النانوسيليكا المحسنة |
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Subject |
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Faculty of Meteorology, Environment and Arid Land Agriculture |
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Document Language |
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Arabic |
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Abstract |
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The discharge of heavy metal ions from various anthropogenic as well as natural sources has a severe impact on human health and environment. The excessive concentration of heavy metals (HMs) including Cu(II), Cr(VI), Fe(II) and Mn(II) can be harmful to water also remain a severe effect on the ecological cycle and human health. Many techniques have been applied to remove HMs form the aqueous system. Adsorption by modified nanomaterials is one of the most promising technique. Silica (SiO2)-based nanocomposites (silica polymers, silica metal oxides) have been explored for the various environmental applications including adsorption due to their unique characteristics.
In this thesis, multifunctional graphene oxide/silica@polyaniline (GO/SiO2@PANI) and silica/copperferrite/polyaniline (SiO2/CuFe2O4/PANI) adsorbents were synthesized and characterized. The prepared nanocomposites were applied for the removal of Cu(II), Cr(VI), Fe(II), and Mn(II), ions, respectively, from groundwater and synthetic wastewater. The morphology and other structural properties of materials were characterized by scanning electron microscopy (SEM), transmission electron microscopy(TEM), Brunauer -Emmett- Teller (BET) surface area, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and fourier transform infrared (FTIR). The synthesized adsorbents were evaluated in a batch adsorption process. Different factors affecting the adsorption process were investigated and found that studied metals adsorption was highly dependent on the solution pH, temperature and the initial metal ions concentrations.
The adsorption of Cu(II) and Cr(VI) ions in synthetic wastewater onto GO/SiO2@PANI composite was rapid and the optimum pH values were 5.3 and 3.0 for Cu(II) and Cr(VI), respectively. Classical isotherm models indicated that Langmuir and Freundlich fitted well Cu(II)) and Cr(VI) adsorption data at 30, 40, and 50 °C. The monolayer adsorption capacities were 258.27‒314.11 mg/g for Cu(II) and 512.47‒540.17 mg/g for Cr(VI). On the other hand, ̴ 96% of Cr(VI) ions and ̴ 81% of Cu(II) ions adsorption efficiency was observed in groundwater sample within 5 hours of reaction time. The FTIR and XPS analysis revealed that the electrostatic interaction between the Cu(II) ions and the deprotonated GO/SiO2@PANI function groups played the main role in adsorption process. Hexavalent chromium was removed in the form of HCrO4− via electrostatic interaction. The adsorption energies of Cr(VI) and Cu(II) were below 40 kJ/mol signifying endothermic process governed by physical interactions.
The adsorption of Fe(II), Cu(II) and Mn(II) from groundwater onto SiO2/CuFe2O4/PANI was found to be ̴ 78%, ̴ 43% and ̴ 42% of Fe(II), Cu(II) and Mn(II) ions within 5 hours, respectively. Moreover, the synthesized SiO2/CuFe2O4/PANI was also evaluated for the adsorption of Fe(II), Mn(II) and Cu(II) ions from synthetic water solution at optimum operating factors. The results revealed that adsorption capacity of SiO2/CuFe2O4/PANI for Fe(II), Mn(II) and Cu(II) was 320 mg/g, 296 mg/g, and 176 mg/g, respectively.
Regeneration studies of GO/SiO2@PANI and SiO2/CuFe2O4/PANI showed that both of the adsorbents are excellent renewable materials and potential for further use for wastewater decontamination. Therefore, the GO/SiO2@PANI and SiO2/CuFe2O4/PANI both are considered and recommended as promising adsorbents for metal ions adsorption. |
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Supervisor |
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Prof. Dr. Mohamed Abu El-Fetouh Barakat |
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Thesis Type |
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Master Thesis |
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Publishing Year |
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1442 AH
2020 AD |
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Co-Supervisor |
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Dr. Rajeev Kumar |
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Added Date |
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Saturday, September 12, 2020 |
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Researchers
| مد أبو طالب | Abu Taleb, Md | Researcher | Master | |
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