DC 欄位 值 語言 DC.contributor 環境工程研究所 zh_TW DC.creator 李向曦 zh_TW DC.creator Hsiang-hsi Lee en_US dc.date.accessioned 2012-7-30T07:39:07Z dc.date.available 2012-7-30T07:39:07Z dc.date.issued 2012 dc.identifier.uri http://ir.lib.ncu.edu.tw:88/thesis/view_etd.asp?URN=993206019 dc.contributor.department 環境工程研究所 zh_TW DC.description 國立中央大學 zh_TW DC.description National Central University en_US dc.description.abstract 本研究利用奈米碳管吸附鄰-硝基苯酚(2-NP)、對-硝基苯酚(4-NP)及銅離子(Cu2+)，探討其競爭吸附及機制。研究結果顯示，經硝酸氧化處理後，比表面積與氧化前差異不大，但在碳管表面引入官能基－COOH，使得碳管表面電荷有所改變，造成對2-NP、4-NP及Cu2+的吸附影響。等溫吸附實驗顯示，碳管的含氧官能基多寡會影響2-NP、4-NP及Cu2+之吸附量，未經氧化奈米碳管吸附2-NP及4-NP之吸附量會優於氧化後奈米碳管，和空間障礙及水簇作用有關。而氧化後奈米碳管對吸附Cu2+之吸附量會大於未氧化碳管，會因官能基的增加提高碳管表面負電荷，導致吸附量提高。2-NP與4-NP因電子分佈之影響，氧化前後奈米碳管對4-NP的吸附能力較2-NP低；不論酸氧化前後奈米碳管，對於2-NP及Cu2+之吸附皆較為符合Langmuir模式，而對於4-NP之吸附則較為符合polanyi 模式。經熱力學分析得知酸氧化前後奈米碳管吸附2-NP及4-NP均為放熱反應；而酸氧化前後奈米碳管吸附Cu2+為吸熱反應。在不同pH值下，酸氧化後奈米碳管吸附2-NP及4-NP之吸附量具有相同的趨勢，與分子解離及表面電荷有關；吸附Cu2+則與表面電荷及沉澱有關。在2-NP及4-NP存在下之競爭結果顯示，碳管吸附Cu2+之吸附量增加，因2-NP及4-NP解離後將可能與Cu2+形成新物質或錯合物，提高Cu2+之吸附百分比；但在pH值小於7時，Cu2+將對氧化後奈米碳管吸附2-NP及4-NP產生抑制作用，與水合作用產生遮蔽效應有關。 zh_TW dc.description.abstract Adsorption of 2-nitrophenol (2-NP), 4-nitrophenol (4-NP), and copper (Cu2+) by multi-walled carbon nanotubes (MWCNTs) with and without oxidation by nitric acid were investigated in this study. The adsorption capacities of 2-NP and 4-NP by A-MWCNT were larger than H-MWCNT, because of steric obstructions and water clustering. On the other hand, H-MWCNT had better adsorption capacity of Cu2+ than A-MWCNT, because the functional groups generated more negatively charged surface. Furthermore, MWCNTs had better adsorption capacity of 2-NP than 4-NP due to the electronic distribution. The adsorption of 2-NP and 4-NP by MWCNTs were endothermic while the adsorption of Cu2+ was exothermic. The enthalpy change and free energy change suggested that the adsorption of 2-NP, 4-NP, and Cu2+ onto MWCNTs were physisorptions. The adsorption at different pH values showed that the adsorption of 2-NP and 4-NP by H-MWCNT had the same trend, relating to the molecular dissociation and surface charge, while the adsorption of Cu2+ was affected by the surface charge and precipitation. When 2-NP or 4-NP were present, the adsorption of Cu2+ was promoted, because complexes of 2-NP/Cu and 4-NP/Cu may form after 2- and 4-NP dissociated. When pH values were lower than 7, the adsorption of 2-NP and 4-NP would be inhibited by Cu2+ due to the shielding from hydration of Cu2+. en_US DC.subject Polanyi model zh_TW DC.subject Langmuir model zh_TW DC.subject 競爭吸附 zh_TW DC.subject competitive adsorption en_US DC.subject Polanyi model en_US DC.subject Langmuir model en_US DC.title 奈米碳管對於硝基酚與銅之競爭吸附 zh_TW dc.language.iso zh-TW zh-TW DC.title Competitive adsorption of nitrophenol and copper(II)from aqueous solutions on mult-walled carbon nanotubes en_US DC.type 博碩士論文 zh_TW DC.type thesis en_US DC.publisher National Central University en_US