複合鐵A 在土壤管柱之傳輸與催化 Fenton-like 反應能力之評估

The evaluation of transport and catalytic ability of Fe (III) complex A for Fenton-like reaction in soil column

吳憲祐(Hsien-Yu Wu)

指導教授 ： 葉桂君

國立屏東科技大學/工學院/環境工程與科學系所/碩士(2008年)

https://doi.org/10.6346/NPUST.2008.00205

摘要

傳統 Fenton 法是以在酸性環境下較穩定之亞鐵離子為催化劑，然而此方法亞鐵離子會最後會形成水合鐵而沉澱，導致反應所需的鐵離子逐漸減少，且 Fenton 法須在酸性環境下進行反應，對環境衝擊較大，在現地土壤及地下水整治上較不可行。利用有機酸或螯合劑與鐵離子(Fe (II)或 Fe (III))複合所得到之新式複合鐵催化劑為改良式 Fenton-like 法之一，此法在原本的 Fenton 試劑中加入複合鐵，可以保持鐵離子存在的時間，進而維持 Fenton-like 反應的效率。
以本實驗室先前研究成果為基礎，進行最佳複合鐵A 之灌注比例實驗，最後評估以最佳複合鐵A 之灌注比例於土壤管柱中催化 Fenton-like 反應氧化溶解相苯及甲苯之能力。在批次實驗中，複合鐵A 催化 0.5% 及 1% H2O2 降解甲苯有良好的效果且複合鐵A 具有重複催化 H2O2 的能力。複合鐵A 1 : 2 及 1 : 5 (M/M，Fe (III)= 0.5 mM)能傳輸達 120 cm以上，而複合鐵A 1 : 1 (M/M，Fe (III)= 2 mM)的傳輸距離僅 80 cm，顯示降低鐵濃度且增加有機酸莫耳濃度可以增加複合鐵的傳輸距離。含有複合鐵A 1 : 2 的土壤管柱在通過 2% H2O2 時產氣量較小，故選擇以複合鐵A 1 : 2 為最佳灌注比例。在評估最佳複合鐵A 中顯示，土壤管柱中苯及甲苯主要之去除機制為 Fenton-like 氧化，其次為複合鐵A 中有機酸A 對苯及甲苯的共溶劑效應，導致增加苯及甲苯之溶出。

關鍵字

類 Fenton法 ； 複合鐵A ； 苯 ； 甲苯 ； 土壤管柱

並列摘要

The catalyst used for traditional Fenton oxidation process is the ferrous ion form under acidic solution pHs. However, during the Fenton reaction, Fe hydroox precipitates form and the oxidation efficiency is significantly reduce. Also the Fenton reaction must be carried out under the acidic environment so it is not feasible for the soil and groundwater remediation. One of the Fenton-like process (also called the modified Fenton reaction) is the use of organic acid or chelate complexed with Fe (II) or Fe (III) as a new catalyst. A Fe (III)-organic acid A complex (named the Fe (III) complex A), developed in our previous batch study, has shown that the Fe (III) complex A can keep the iron ion exist stably in the solution and therefore maintain the oxidation efficiency.
This study continue to test the transport and catalysis of Fenton-like oxidation of benzene and toluene by the developed Fe (III) complex A in soil columns, using the optimum Fenton-like reaction condition found previously. First the results in batch experiments found that more toluene was removed by the Fenton-like oxidation catalyzed by Fe (III) complex A at 0.5% and 1% H2O2 than benzene. More toulene degradation ocuurred by the repeated H2O2 dose. The results in the column tests revealed that the Fe (III) complex A solution at Fe (III) : organic acid (A) molar ratio = 1 : 2 and 1 : 5 can transport over 120 cm. By contrast, the Fe (III) complex A solution at Fe (III) : organic acid (A) molar ratio = 1 : 1 (Fe = 2 mM) only transported less than 80 cm. Thus, it was concluded that using a lower Fe (III) concentration, with elevated organic acid A concentration can increase the Fe (III) transport distance. The gas production in soil column from the Fenton-like decay of 2% H2O2 catalyzed by the Fe (III) complex A at M/M ratio = 1 : 2 (Fe = 0.5 mM) was less than that by M/M ratio of 1: 5. The Fenton-like reaction catalyzed by the studied Fe (III) complex A at Fe (III): organic acid A molar ratio = 1 : 2 can successfully catalyze H2O2 and oxidize benzene and toluene in soil column. It was found that the Fe (III) complex A also acted as a co-solvent during transport which enhanced benzene and toluene movement in soil columns.

並列關鍵字

Fenton-like reaction ； Fe (III) complex ； benzene ； toluene ； soil column

參考文獻

陳家洵，2004，地下水及土壤污染，中興工程科技研究發展基金會，台北。

行政院環保署，2007，95年度土壤及地下水污染整治年報。

丁力行，2000，土壤及地下水污染整治法實務與因應對策，永然文化，台北。

葉桂君、陳韋舜、陳偉一、陳家銘，2003，「中性pH條件下Fenton-like反應不同鐵氧礦物催化過氧化氫之氫氧自由基生成」，第八屆土壤及地下水污染整治研討會論文集，第261-270頁。

林財富、鄭仲凱，2003，「現地化學氧化技術之發展與案例分析」，第八屆土壤及地下水污染整治研討會論文集，第127-140頁。