| Summary: | 碩士 === 弘光科技大學 === 環境工程研究所 === 100 === The physical and chemical properties of MWCNTs, were determined with Fourier transform infarared spectroscopy (FTIR), thermgravimetric analyzer (TGA), Boehm's titration, and field emission scanning electron microscope (FESEM). The kind of MWCNTs used for Hg(II) adsorption experiments including bonding phenolic functional group (MWCNTs-OH), bonding carboxylic functional group (MWCNTs-COOH), which modified surface chemical characteristics by acids. The commercial activated carbon (named AC-F400) was also apply for same test process. The results from the kinetic experiments indicated that the MWCNTs modified by oxidants acids, which the catalytic metal and media have been removal during acidification and oxidation processes. Moreover, the tip of MWCNTs would cut by acid or oxidant, then increased the surface area, activated sites, and oxygen-rich functional group. The results also show that the aadsorption of Hg(II) on the MWCNTs is strongly dependent on pH. The adsorption capacity of the adsorbents for Hg(II) in pH 4.3 is higher than that of pH over 9, which adsorption capacity wrer decreased 3-4 time than pH 4.3. Additionally, compare with the four adsorbents in adsorption capacity of Hg(II), the ranking are MWCNTs-OH > MWCNTs-COOH > AC-F400 > MWCNTs-Raw. Results of adsorption kinetic model and isotherm model for fits the experimental data shows that the pseudo second-order kinetic model fits the adsorption kinetic data of Hg(II) is better than other kinetic models. Moreover, the Freundlich model fits the adsorption isotherm data better than the Langmuir model.
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