| 摘要: | 鄰-甲苯胺是已知的毒化物及致癌因子，此物質廣泛的應用於大部分的工業生產上，但在工廠排放廢水之前的處理，便是首要工作。在本研究中利用 Photo Electro-Fenton 程序來深入探討處理鄰-甲苯胺。在比較過不同 Fenton 程序降解鄰-甲苯胺後，發現其 Photo Electro-Fenton 中降解鄰-甲苯胺之效率優於 Fenton、Photo-Fenton、及Electro-Fenton，因此選擇 Photo Electro-Fenton 程序做為本研究中降解鄰-甲苯胺之主要程序。
研究中以 Box-Behnken實驗設計對 Photo Electro-Fenton 程序降解鄰-甲苯胺做實驗設計，其目的在於以最有效之方式找出 Photo Electro-Fenton 程序處理鄰-甲苯胺之最佳實驗參數，並探討在此程序中各項實驗操作因子對於鄰-甲苯胺及總有機碳去除之影響。
結果指出在 Photo Electro-Fenton 程序降解鄰-甲苯胺中，亞鐵離子濃度與過氧化氫濃度為此程序之主要因素，亞鐵離子濃度與過氧化氫濃度提升其產生之氫氧自由基量產量較高，鄰-甲苯胺之去除效率也隨之提升，但過量之亞鐵及過氧化氫濃度將使反應速率下降，在UVA燈數及電流量對於此程序去除鄰-甲苯胺之影響較小，但提升UVA燈數及電流量亦可提升對鄰-甲苯胺之去除效率。
在處理鄰-甲苯胺之最適條件，當使用亞鐵 1mM、過氧化氫 9mM、UVA燈管8支、電流量1.5A時鄰-甲苯胺去除效率為100%，反應時間40分鐘，總有機碳去除於120分鐘34.05%。其處理鄰-甲苯胺之最速條件為亞鐵 1mM、過氧化氫 5mM、UVA燈管12支、電流量1.5A，反應於20分鐘即可去除100%之鄰-甲苯胺。在礦化作用方面研究中，鄰-甲苯胺可從水樣中完全去除，但總有機碳(TOC)之剩餘率還是非常高，結果顯示在 Photo Electro-Fenton 程序反應期間可能形成中間產物。
o-Toluidine is a toxic pollutant which is widely used in many industries. However, it was found to be caricinogen, so it should be remove from wastewater before release into environment. In this research, the removal of o-toluidine by photoelectron-Fenton process was investigated in depth. Moreover, the comparison between Fenton, Photo-Fenton, Electro-Fenton and Photo Electro-Fenton processes on o-toluidine removal was also studied. The result showed that Photo Electro-Fenton process has the highest ability on o-toluidine degradation.
In Photo Electro-Fenton, the removal of o-toluidine was investigated using Box-Behnken designs to find the key factors and optimum conditions. The effect of initial Fe2+ concentration, H2O2 concentration, number of UVA lamps and electric current were selected as a factor in Box-Behnken whereas o-toluidine removal and TOC removal were considered as response functions. Results indicated that Fe2+ and H2O2 concentrations had positive effects on o-toluidine degradation. Increasing both Fe2+ and H2O2 concentration can produce more hydroxyl radicals, and thus increase the o-toluidine removal efficiency. However, increasing too much Fe2+ and H2O2 concentrations will decrease the removal efficiency. In contrast, the amount of UVA lamps and electric current were not the key factor. Increasing UVA number and electric current can increase the removal of o-toluidine in Photo Electro-Fenton process.
The optimal number of UVA lamps, Fe2+ and H2O2 concentrations, and electric current for the maximum o-toluidine removal (100% in 40 minutes) and TOC removal (34.05% in 120 minutes) were 8 lamps, 1 mM, 9 mM and 1.5 A, respectively. In addition, the fastest o-toluidine removal efficiency can be achieved in 20 minutes (100% removal) when Fe2+ 1 mM, H2O2 5 mM, UVA 12 lamps and electric current 1.5 A were applied. The results also showed that even o-toluidine could completely remove from the solution by Photo Electro-Fenton process, however, TOC was still high. This is probably due to the intermediates that might occur in the reaction. |
