綠色普通化學實驗設計:以費頓試劑氧化染料之使用及可行性

Designing Green Chemistry Experiments：Feasibility of Fenton Reagent as an Oxidant on Dyes

李華光(Hua-Kwang Lee)

指導教授 ： 葉華光

中原大學/理學院/化學研究所/碩士(2011年)

https://doi.org/10.6840/cycu201100775

摘要

本研究目的為設計出一個簡單且有趣的綠色普通化學實驗，俾此向大學生介紹、推廣綠色化學的概念。
實驗架構在全程使用水溶性試劑、得到安全可降解的產物，減少對環境的負擔。實驗方法是利用非光化學程序如費頓及類費頓等試劑(Fenton、Fenton-like reagent)分解兩種常見染料：結晶紫(Crystal Violet，CV)、酸藍(Acid Blue 1，AB1)，以比色法觀察其去色效率。
實驗過程中，以田口直交法分析Fenton試劑中的顯著因子，探討pH值、Fenton (FeSO4/H2O2)、Fenton-like (Fe(NO3)3/H2O2)莫耳濃度比值的變化，並以UV吸收計算樣品的分解效率以及推算反應之化學動力學。根據研究結果顯示pH對CV降解影響最為顯著。低pH值(pH=3)下，反應可在10分鐘內完成，在pH=5的環境下，反應會延宕至60分鐘以上甚至會出現鐵離子的混凝現象使反應不完全。我們選擇最合適應用於普化實驗之條件為pH 4，同時FeSO4：H2O2 與Fe(NO3)3：H2O2之最適合莫耳濃度比皆為0.5：50 mM。藉由UV的輔助，我們可以得知Fenton系統的反應性很好，反應時間5分鐘時，CV分解效率均可超過70%。
此外，我們挑選另一支結構相近、性質不同的樣品Acid Blue 1，來測試Fenton reagent的反應是否有專一性。由實驗結果呈現Fenton reagent對AB1也有相同的高反應性，變因的影響條件也與CV相同，在pH=3時反應最為快速，可在10分鐘內將AB 1去除至無色。最適合之條件FeSO4：H2O2 比值為0.5：50 mM，在pH為4的條件下，能有更清晰的判斷出顏色變化趨勢。

關鍵字

費頓試劑 ； 綠色化學

並列摘要

The goal of this study is to develop a protocol for promoting the concept of green chemistry to college students. We designed the degradation products that they do not persist in the environment. We used the solvent in this system by water to reduces the toxicity in the environment. The most suitable protocol was tested by evaluating the non-photochemical process (Fenton, Fenton-like) in removing two of the commonly used dyes, Crystal Violet (CV) and Acid Blue 1 (AB1). The colorimetric process is applied to evaluate the outcome in this protocol.
Experimental parameters were analyzed by Taguchi orthogonal arrays. Evaluation of the effect of pH and molarity ratio of Fenton (FeSO4/H2O2)、Fenton-like (Fe(NO3)3/H2O2) and then coupled with UV/Vis spectrophotometer was used to detect the removal efficiency and chemical kinetics of the sample. Results showed that pH played an important role in this system. At the pH=3, the reaction was finished for 10 minute. For CV the ideal pH for FeSO4/H2O2 (0.5 mM：50 mM) and Fe(NO3)3/H2O2 (1 mM：50 mM) was about 4 with a concentration of 50mM.
Another dye, Acid Blue 1, was chosen to test the reactivity of Fenton reagent. Identical experiments parameters as for CV were applied and the optimal pH was found to be 4, with 50 mM of AB1, and FeSO4/H2O2 = 0.5：50. With these terms, color changed could be observed readily.

並列關鍵字

Fenton reagent ； Green chemistry

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