文獻雖提及零價鐵處理Atrazine效果相當好，但是所使用之操作條件、結果不盡相同，因此本研究結合零價鐵與現有處理技術去降解Atrazine，比較零價鐵在不同處理系統中之差異。而研究過程中所採用之處理系統有：(1)零價鐵管柱床(2)零價鐵流體化床(3)零價鐵曝氣槽實驗，皆有其優缺點，期望找出最佳條件及解決方式。
實驗過程中發現Atrazine降解過程包含氧化及還原機制。在流體化床及曝氣槽實驗中，由降解Atrazine速率來看，還原機制明顯比氧化機制慢了許多，且會隨pH變化而不同。如實驗結果顯示在pH 3及2時，Atrazine去除效果隨著添加之鐵量增加而提高，可達到70%及90%。然而於pH 4時Atrazine去除效果增加的趨勢並不明顯。原因為鐵反應後產生之氧化物覆蓋於鐵表面，而pH 4之氫離子濃度並無法完全降低氧化物量，因此零價鐵電子傳遞受到影響，使Atrazine降解效果降低，因此建議零價鐵流體化床與曝氣槽系統最佳pH值之選擇為pH 3以下。但是以上所得到之結論並不符合管柱床系統之趨勢，由實驗結果顯示管柱床系統中pH控制於中性時Atrazine降解效果較好，原因為管柱床系統進流水pH值越低，所產生之氧化物越多，使降解Atrazine之效果變差。若於零價鐵系統中添加H2O2，其產生之Fenton反應有效提升Atrazine去除效果，且Atrazine於幾分鐘就可以完全去除。

Several papers had pointed out zero valent iron could degrade atrazine effectively. However, different operation conditions applied among these studies make the results quite different. In this study, Zero-valent iron (ZVI) for degradation of atrazine was applied in different treatment process and the results were compared. Three treatment systems were studied, including (1) zero valent iron column bed reactor, (2) fluidized zero valent iron reactor, and (3) zero valent iron purging bed reactor. All of them have their inherited advantages and disadvantages which will be elucidated along with the suggestions of best operational conditions for these processes.
Both reductive and oxidative mechanisms are responsible for degradation of atrazine on our experiment. In the fluidized zero valent iron reactor and zero valent iron purging bed reactor, the degradation of atrazine by reductive mechanism is a much slower process than that by oxidative mechanism, and is pH dependent. At pHs of 3 and 2, atrazine degradation efficiency increased with increasing ZVI dosages, up to 70% and 90%. But the increasing trend is not observed for system controlled at pH 4.0. It is due to passive surface coating by corrosion iron products at this pH. The concentration of hydrogen at pH 4 is not enough to reduce the amount of iron corrosion products, which influence transfer of electrons and reduce the effectiveness of atrazine degradation. Therefore, operational pH of under 3 is suggested. But the effect of pH is not the same with that observed in column bed reactor. The effectiveness of atrazine degradation is better when influent pH is controlled at near neutral. When influent pH was controlled at acidic range, more iron corrosion products were produced, decreasing the effectiveness of atrazine degradation. Addition of H2O2 greatly enhanced removal of atrazine through Fenton reaction, and atrazine degradation was completely within the first few minutes of reaction.

目錄
第一章、 前言.............................................1
1.1 研究背景..............................................1
1.2 研究之方向及目標......................................2
第二章、 文獻回顧.........................................3
2.1 地下水污染物的來源....................................3
2.2 除草劑的處理方式......................................6
2.3 應用零價鐵之國外研究.................................11
2.3.1 pH變化之影響.......................................11
2.3.2 零價鐵鐵量之影響...................................13
2.3.3 溶氧之影響.........................................14
2.4 反應機制.............................................16
2.4.1 還原機制...........................................16
2.4.2 氧化機制...........................................16
第三章、 實驗材料與方法..................................17
3.1 實驗材料.............................................17
Atrazine之結構式如下:....................................17
Atrazine的配製...........................................17
3.2 實驗方法.............................................18
3.2.1. 零價鐵管柱床實驗設置與條件........................18
3.2.2. 零價鐵流體化床實驗設置與條件......................19
3.2.3. 零價鐵曝氣槽實驗設置與條件........................21
3.3 分析方法.............................................23
3.3.1. Atrazine分析之方法及步驟：........................23
3.3.2. Fe2+分析之方法及步驟：............................24
3.3.3. 總鐵分析之方法及步驟：............................24
第四章、 結果與討論......................................26
4.1 零價鐵管柱床系統.....................................26
4.2 零價鐵流體化床系統...................................35
4.3 零價鐵曝氣槽系統.....................................45
4.4 探討零價鐵與H2O2之反應...............................49
第五章、 結論與建議......................................52
參考文獻	................................................54

 
圖目錄
Figure 1. Zero valent iron Column bed reactor............19
Figure 2. Fluidized zero valent iron bed reactor.........20
Figure 3. Zero valent iron purging bed reactor...........22
Figure 4.The elution of Atrazine analyzed by HPLC. Concentrations of Atrazine varied from 0 to 1 mg l-1. Wavelength of UV detector set at 224 nm..................23
Figure 5. The standard curves of Fe2+ concentrations. Analysis according to the Standard Methods 20th edition（3500-B）Phenanthroline Method..........................24
Figure 6. The standard curves for analysis of Total Fe concentrations...........................................25
Figure 7. Removal efficiency of atrazine as a function of reaction time at various pH conditions with N2 puraged. ZVI concentration = 10 g l-1.................................27
Figure 8. The pressure change of column as a function of reaction time at various pH conditions with N2. ZVI concentration = 10 g.....................................28
Figure 9. Removal efficiency of atrazine as a function of reaction time at various pH conditions with Air. ZVI concentration = 10 g.....................................30
Figure 10. The pressure change of column as a function of reaction time at various pH conditions with Air. ZVI concentration = 10 g.....................................30
Figure 11. Removal efficiency of atrazine as a function of reaction time at various pH conditions with O2. ZVI concentration = 10 g.....................................31
Figure 12. The pressure change of column as a function of reaction time at various pH conditions with O2. ZVI concentration = 10 g.....................................32
Figure 13. Removal efficiency of atrazine as a function of reaction time at various pH conditions with O2、N2 and Air. ZVI concentration = 10 g.................................34
Figure 14. The removal efficiency of atrazine as a function of reaction time at various pH conditions. Initial atrazine and ZVI concentrations are 1 mg l-1 and 20 g/L, respectively. Reactor volume of 1L. Error bar represents one standard deviation from the mean (The number of tests, n, for calculating the mean and standard deviation is 3).......................................................36
Figure 15. Concentration of Fe2+ and Total Fe content for pH 4.0 system shown in Figure 14.........................37
Figure 16. The amount of Atrazine removed per gram of Fe dissolved as function of reaction time. Initial atrazine and ZVI concentrations are 1 mg l-1 and 20 g/L at pH 4...38
Figure 17. Atrazine removal efficiency for various pH conditions . ZVI=20g/L...................................39
Figure 18. Adsorption of atrazine by freshly precipitated iron oxide (Total iron concentration = 10 mM) at various pH conditions. Initial atrazine= 1 mg l-1. Reaction time = 2 hours....................................................40
Figure 19. Removal efficiency of atrazine as a function of reaction time at pH 4 at various purging conditions. ZVI concentration = 20 g l-1.................................42
Figure 20.Removal efficiency of atrazine as a function of reaction time at pH 4 under various concentrations of ZVI dosages..................................................43
Figure 21. The removal efficiency of atrazine after 30-minute reaction as a function of ZVI dosages for various pHs conditions. Initial atrazine concentration is 1 mg l-1........................................................46
Figure 22. Atrazine removal efficiency as function of time for sequential ZVI addition at pH 4......................47
Figure 23. Removal efficiency of atrazine as a function of reaction time at pH 3 at various purging conditions. ZVI concentration = 20 g l-1.................................48
Figure 24. Removal efficiency of atrazine as a function of reaction time at pH 3 under various concentrations of H2O2 with Fe2+. Fe2+=150ppm...................................49
Figure 25. Removal efficiency of atrazine as a function of reaction time at pH 3 under various concentrations of H2O2 with or without ZVI. ZVI concentration = 20 g l-1........51

 
表目錄
表 1零價鐵管柱床出流水之pH值.............................34
表 2、Atrazine之殘留農藥安全容許量：單位為mg l-1.........58

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土壤與地下水整治：污染來源及新型整治方法之介紹

農業藥物毒物試驗所
行政院環境保護署
林財富, 洪旭文 (1999): 受污染場址現地化學處理方法介紹, 工業污染防治, 72,178-200.
林財富:土壤與地下水整治：污染來源及新型整治方法之介紹
陳孝行, 徐嘉彬 (1999): 零價鐵金屬牆去除地下水中硝酸鹽氮之研究