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 Inorganic Pollutants from Aqueous Solutions using Different Nano Materials إزالة الملوثات غيرالعضوية من المحاليل المائية بواسطة مواد نانونية مختلفة |
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Subject |
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Faculty of Sciences > Chemistry departmen |
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Document Language |
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Arabic |
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Abstract |
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The increase in demand for water and food supplies is placing increasing stress on ground and surface water quality and quantity. One environmental problem that has become an increasingly important issue in developed and developing countries is nitrate contamination of surface water and groundwater. Many methods were investigated to remove nitrate ions from water, among these methods is the catalytic reduction. The main goal of this thesis is to remove nitrate ions from water by catalytic reduction reaction pathway using three composites made of zero valent iron nanoparticles (ZVINPs) supported on different carbonaceous nano materials; nano graphenes (NGs), multi-walled carbon nanotubes (MWCNTs). Firstly, ZVINPs were produced by adding sodium borohydride (NaBH4) drop wisely to ferric chloride solution (FeCl3), at which ferric (Fe3+) was reduced into ZVINPs. For the reduction reaction, an appropriate amount of ZVINPs were supported onto graphene and MWCNTs through a physical mix forming the two nanocomposites ZVINP/NG and ZVINP/MWCNTs. In another experiment, nitrate ions were reduced using ZVINPs coated with copper (Cu-ZVINPs), which were prepared by reacting CuCl2 solution with freshly prepared ZVINPs. The produced bimetallic particles were then supported onto MWCNTs forming another nanocomposite Cu-ZVINP/MWCNTs. The three produced nanocomposites were characterized by XRD, BET and TEM techniques. These three nanocomposites were predicted and experimentally proven to possess high ability for nitrate ions reduction. The results showed that supporting ZVINPs on both NGs and MWCNTs gave high removal values compared with ZVINPs alone for nitrate ions reduction. The effect of different factors that affecting the removal process were studied, and generally the results showed that the removal efficiency increased with increasing contact time, nanocomposite dosage, solution temperature, and ultrasonication (US) time, on the other hand; it decreased with increasing solution pH and nitrate ions concentration. Also we studied the effect of co-existing anions and cations, at which these nanocomposites showed a great and promising results as they have the ability to remove nitrate ions in the presence of different anions and cations, in addition their great tendency for removing most of these anions and cations as well. From the kinetic studies of the nitrate ions reduction and by applying several kinetic models, the results revealed that pseudo-second-order kinetic model could fit and describe the reduction of nitrate, confirming that the reaction depends on both active sites on ZVINPs surface and nitrate ions concentration. Also, the thermodynamic studies showed a negative value for ΔG and positive values for both ΔH and ΔS, indicating that the reaction is entropy-driven process. The mechanism of the catalytic reduction of nitrate ions was studied , and it was found that the mechanism using ZVINPs alone didn’t differ from mechanism using the three nanocomposites, except in the nitrate removal amount which increased in case of supporting ZVINPs over NGs and MWCNTs. Also, the amount of released ammonium differed due to the adsorption of ammonium by the supporting materials; NGs and MWCNTs, in the three studied nanocomposites ZVINP/NG, ZVINP/MWCNTs and Cu-ZVINP/MWCNTs. Removal of ammonium by these supporting material showed promising composites as no further treatment to remove the produced ammonium, which is the main reduction product. The applicability of the three nanocomposites for the reduction of nitrate ions were studied using real samples collected from different environments, and the results showed promising results that indicating the importance, applicability and tendency of these nanocomposites to remove nitrate ions from various environments with an easy, simple and low cost method. |
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Supervisor |
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Dr. Mohamed Abdel Salam |
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Thesis Type |
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Master Thesis |
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Publishing Year |
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1437 AH
2016 AD |
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Co-Supervisor |
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Prof. Shaeel A. Al-Thabaiti |
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Added Date |
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Monday, February 29, 2016 |
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Researchers
| الفت محمد فقيه | Fageeh, Olfat Mohammed | Researcher | Master | |
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