駱尚廉Lo, Shang-Lien臺灣大學:環境工程學研究所陳秀瑜Chen, Hsiu-YuHsiu-YuChen2010-05-102018-06-282010-05-102018-06-282009U0001-2007200916501900http://ntur.lib.ntu.edu.tw//handle/246246/181603硝酸鹽氮為自然界中常見污染源，主要因農業過度施肥而入滲至土壤造成地下水之污染，一旦攝入過多硝酸鹽，硝酸鹽氮將還原成亞硝酸鹽氮，而阻礙血液氧氣的輸送。而本研究利用氧化鈦奈米管(TNTs)作為批覆鈀、銅雙金屬之載體，並同時將此雙金屬批覆於二氧化鈦(TiO2)上，作為比較兩者間作為載體時，用以降解硝酸鹽之優劣。酸洗程序為TNTs合成之重要因子，故將雙金屬批覆於三種不同酸洗程序之TNTs上，其中以鹽酸酸洗最為有助於TNTs之成形。而批覆20%之銅鈀雙金屬具最佳之硝酸降解速率及氮氣選擇性。為了解觸媒之持續利用性，故進行多次加藥試驗。Pd-Cu/TNTs系統中，氮氣選擇性於第六循環反應中才明顯減少；而Pd-Cu/TiO2系統之氮氣選擇性則隨著循環數增加而遞減。利用表面化學元素分析儀(ECSA)分析各循環反應後觸媒之鈦、銅及鈀之鍵能變化可知，TiO2表面之Pd及Cu反應後，其鍵能明顯偏移至較高鍵能，而因TNTs為電子提供者，故表面金屬無明顯氧化現象。換言之，TNTs可視為一犧牲形材料而避免金屬受到氧化。氣中之氧化物質將使觸媒表面之金屬受到嚴重氧化而失去活性，而因TNTs為管狀結構，致使管內金屬不易與空氣接觸而無法被氧化，因此置於空氣15天後之Pd-Cu/TNTs，其表面上只有部份金屬受到氧化，而TiO2表面金屬則因直接接觸空氣而完全受到氧化，因此TNTs作為載體時，可避免其表面金屬於空氣中迅速失去活性。含鈀觸媒具良好催化硝酸之能力，然而因水體中往往含其它陰陽離子而影響其反應性，故本研究利用不同濃度硫化鈉進行積垢試驗，了解觸媒受毒化之敏感性。相較於Pd-Cu/TiO2，Pd-Cu/TNTs較不易受到硫離子之毒化。而最後分別利用氧化還原等程序再生Pd-Cu/TNTs之，尋求有效之再生方法。而以硼氫化鈉作為再生劑可有效回復硝酸降解速率；反之，利用次氯酸鈉作為還原試劑反而更加減緩觸媒之反應性。Nitrate contamination is widespread due to over-fertilization in agriculture. Once taken into the body, nitrates are converted into nitrites, which can interfere with the oxygen-carrying capacity of the blood. This study examined the removal of aqueous nitrates (NO3-) by catalytic hydrogenation over microwave-induced titanate nanotubes supported bimetallic Pd-Cu catalysts (Pd-Cu/TNTs), and used Pd-Cu/TiO2 to be the contrast.ecause acid-treating step are the key factor affecting the physical property of TNTs, three different acid reagents were used to treat TNTs, and the effect of loading amount of bimetallic metals was also studied. In terms of the selectivity to N2 and the degradation kinetic of nitrate, the optimum loading amount located at 20% w.t., and HCl was the best reagent to assist in TNT synthesis.ith an intention to explore the sustainability of Pd-Cu/TNTs, a multi-spiking test was also carried out and the selectivity to N2 decreased only at the 6th cycle. But for Cu-Pd/TiO2, the selectivity to N2 yield decreased with each cycle. Based on the Cu 2p and Pd 3d spectra analyzed by Electron Spectroscopy for Chemical Analysis (ESCA), a relatively more shift to higher binding energy was observed in the case of Cu-Pd/TiO2. And TNTs were the electron donor so that a trivial shift to higher binding energy was observed after reactions. That means almost no oxidation process occurred for bimetals supported TNTs after reaction. In other words, TNTs can be considered as a sacrifice material to prevent the supported bimetallic catalysts from being oxidized.atalyst can be deactivated due to the oxidant in the air, but only partial metals on the TNTs’ surface were oxidized. This result is probably owing to its tube shape so that metals inside TNTs could not contact with air. In the contrary, metals of Pd-Cu/TiO2 were oxidized more. Therefore, TNTs can prevent metals from oxidation in the air.lthough Pd-based catalysts provide efficient reduction, it requires successful approaches for catalyst regeneration in terms of fouling by constituents in nature water. Therefore, this study also focused on the effect of sulfide-fouled catalysts and found applicable regeneration process. Catalysts were severely deactivated after sulfide poisoning. Nevertheless, Pd-Cu/TNTs were deactivated slighter than Pd-Cu/TiO2. Sulfide-fouled catalysts were studied with oxidative and reductive regenerative conditions. However, only heated air along with sodium borohydride provided efficient recovery of nitrate degradation. On the contrary, Pd-Cu/TNTs were deactivated more after oxidative regeneration.中文摘要 Ibstract III錄 V目錄 VIII目錄 X一章 前言 1-1 研究緣起 1-2 研究目的及內容 2二章 文獻回顧 3-1 硝酸鹽氮之污染及危害 3-1-1 硝酸鹽氮之污染 3-1-2 硝酸鹽氮之危害 4-2 現行硝酸鹽氮之處理技術 4-2-1 生物脫硝法(Biological denitrification) 5-2-2 離子交換法(Ion exchange) 6-2-3 薄膜逆滲透法(Reverse osmosis) 6-2-4 電透析法(Electrodialysis, ED) 7-2-5 化學脫硝法(Chemical Denitrification) 7-2-6 催化脫硝法( Catalytic Denitrification) 8-3 氧化鈦奈米管 9-3-1 氧化鈦奈米管之製備方法 9-3-2 微波水熱法製備氧化鈦奈米管 10-4 積垢及再生之反應 11-4-1 水體中其它離子之影響 11-4-2 硫化物積垢及再生 11三章 實驗方法與內容 13-1 實驗設計 13-2 材料製備 13-2-1 氧化鈦奈米管之製備 13-2-2 金屬修飾材料之製備 15-3 實驗方法 15-3-1 雙金屬負載比例之動力實驗 15-3-2 材料表現及老化之動力實驗 16-3-3 材料積垢及再生實驗 17-4 產物分析 19-4-1 離子層析儀(Ion Chromatography) 19-4-2 氨電極(Ammonia Electrode) 19-5 表面分析 20-5-1 場發射槍掃描式電子顯微鏡/X射線能量分散光譜儀(Field Emission Scanning electron microscope and energy dispersive spectrometer, FEG-SEM/EDX) 21-5-2 場發射槍穿透式電子顯微鏡(Transmission Electron Microscope, TEM) 21-5-3 化學分析電子光譜儀(Electron Spectroscopy for Chemical Analysis, ESCA) 22四章 結果與討論 23-1 背景試驗 23-1-1 氧化鈦奈米管(TNTs)酸洗程序之影響 23-1-2 硝酸還原之pH選擇 25-1-3 載體影響硝酸還原之試驗 27-2 氧化鈦奈米管(TNTs)負載銅鈀金屬量之選擇 29-2-1 氧化鈦奈米管(TNTs)負載銅鈀金屬量之選擇 29-2-2 氮氣選擇性之比較 31-2-3 TNTs與TiO2之比較 32-3 觸媒持續利用性測試 35-3-1 產物分佈探討 35-3-2 觸媒表面分析 38-4 觸媒失活試驗 42-4-1 有氧環境對觸媒活性影響之測試 42-4-2 硫化物對觸媒活性影響之測試 47-5 積垢後再生之測試 52-5-1 再生觸媒之活性測試 52-5-2 觸媒積垢及再生之機制探討 54五章 結論與建議 57-1 結論 57-2 建議 58六章 參考文獻 60錄 實驗數據 65amp;#8195;application/pdf1740681 bytesapplication/pdfen-US硝酸氧化鈦奈米管硫化物積垢再生表面化學元素分析儀nitratetitanate nanotubessulfide foulingregenerationElectron Spectroscopy for Chemical Analysisthesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/181603/1/ntu-98-R96541108-1.pdf