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Document Type |
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Project |
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Document Title |
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Remediation of Persistence Organic Pollutants Using Chemically Modified Carbon Nanotubes. التخلص من الملوثات العضوية الدائمة الثابتة بإستخدام |
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Subject |
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Remediation of Persistence Organic Pollutants Using Chemically Modified Carbon Nanotubes. |
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Document Language |
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Arabic |
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Abstract |
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The effect of different oxidizing agents on the morphological structure of multi-walled carbon nanotubes (MWCNTs) were studied using scanning electron microscopy (SEM). SEM showed that the selection of the suitable oxidizing agent is a very crucial, as two of the used oxidizing agents; sulfuric acid/nitric acid mixture and hydrogen peroxide, were very successful in the oxidation process as they created acidic groups at the MWCNTs surface, removed most of the amorphous carbon, and they did not change the morphological structure of the nanotubes. Meanwhile, potassium permanganate, the third oxidizing agent, was very strong and destroyed most of the MWCNTs. Sulfuric acid/nitric acid mixture was selected as the most suitable oxidizing agent for the oxidation of MWCNTs.
Equilibrium and kinetic studies were conducted for the adsorption of 2, 3-dichlorophenol (DCP), as an example of persistence organic pollutants (POPs), on pristine MWCNTs in aqueous solution. The adsorption of DCP was found to be dependent on mass of MWCNTs, concentration, solution pH, and adsorption temperature. MWCNTs were found to be an excellent adsorbent for the removal of DCP from aqueous solutions in a very short period of time. A comparison of the kinetic models and the overall adsorption capacity was best described by the pseudo second-order kinetic model. The kinetics of the adsorption showed that the adsorption is mainly due to the diffusion of DCP from the aqueous phase to the solid phase. The equilibrium adsorption of DCP on pristine MWCNTs at different temperatures was studied. The thermodynamic parameters showed that the adsorption process is product favored, and becomes more so at lower temperature, since the adsorption is exothermic. The magnitude of the enthalpy suggests a weak type of bonding between the PCP and the MWCNTs. The entropy values were negative, indicating that DCP is more ordered on the aqueous phase than at the MWCNTs surface. |
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Publishing Year |
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1428 AH
2007 AD |
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Added Date |
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Sunday, July 4, 2010 |
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Researchers
| سليمان ناصر باسهل | Basahel, Sulaiman Naser | Investigator | Doctorate | |
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