摘要
鄰-甲苯胺化合物廣泛用於眾多染料工廠是具毒性之污染物。然而，也發現是致癌的因子，所以此物質廢水在釋放到環境之前需預先處理。在研究中，利用Fenton及Photo-Fenton程序來深入性加以探討處理此污染物質。此污染物在Fenton程序方面是以起始pH值、亞鐵及過氧化氫濃度劑量影響作為試驗。當使用1mM的亞鐵濃度和5mM的過氧化氫pH值為3，經過80分鐘反應之後發現鄰-甲苯胺可完全去除。
在Photo-Fenton程序方面，研究中應用實驗套裝軟體進行Box-Behnken設計試驗找出關鍵參數和最佳比例條件去除鄰-甲苯胺。而亞鐵、過氧化氫濃度和UVA燈之影響將會在Box-Behnken中作為參數且鄰-甲苯胺和COD去除率被視為當作反應函數。在結果指出亞鐵和過氧化氫濃度在鄰-甲苯胺去除上確實有影響而UVA燈並不是關鍵參數。最理想的UVA燈、亞鐵、過氧化氫濃度最大量來去除鄰-甲苯胺(預測值100%)和COD去除率(預測值74%)分別為9、1.2和8mM。
對於礦化作用，研究鄰-甲苯胺和總有機碳(TOC)去除效率且結果中顯示鄰-甲苯胺甚至可以從水樣中完全去除，不過，TOC還是非常高。這或許由於中間產物很可能在反應中發生。離子層析(IC)使用於鑑定反應裡的中間產物且結果也顯示在Fenton和Photo-Fenton程序的整個期間，有形成馬來酸(maleic acid)和草酸(oxalic acid)。
另外，鄰-甲苯胺的氧化反應趨勢被發現為二階段反應。第一階段是在亞鐵/過氧化氫反應作用下，而第二階段為三價鐵/過氧化氫之反應。
關鍵詞: 芬頓程序、光-芬頓程序、實驗設計法、鄰-甲苯胺 Abstract
o-Toluidine is a toxic pollutant which is widely used in many industries. However, it was found to be carcinogen, so it should be remove from wastewater before release into environment. In this research, the removal of o-toluidine by Fenton and photo-Fenton processes was investigated in depth. For Fenton process, the effects of initial pH, ferrous ion and hydrogen peroxide dosages on the o-toluidine were examined. The complete degradation of o-toluidine was (100%) found after 80 minutes when used 1 mM of Fe2+ and 5 mM of H2O2 at pH 3.
In photo-Fenton process, 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 and number of UVA lamps were selected as a factor in Box-Behnken whereas o-toluidine removal and COD removal were considered as response functions. Results indicate that Fe2+ and H2O2 concentrations had positive effects on o-toluidine degradation whereas the amount of UVA lamps was not the key factor. The optimal number of UVA lamps, Fe2+ and H2O2 concentrations for the maximum o-toluidine removal (100% from prediction) and COD removal (74% from prediction) were 9, 1.2 mM and 8 mM, respectively.
For the mineralization, o-toluidine and TOC removal efficiencies were examined and the results show that even o-toluidine could completely remove from the solution, however, TOC was still very high. This is probably due to the intermediates that might occur in the reaction. IC was used to identify intermediates in the reaction and the results reveal that during Fenton and photo-Fenton processes, there are formation of maleic acid and oxalic acid. In addition, the oxidation of o-toluidine was found to be a two-stage reaction. The first stage was under the influence of Fe2+/H2O2 reaction whereas the second stage was controlled by Fe3+/H2O2 reaction.
Key words: Fenton process、Photo-Fenton process、Box-Behnken Design、o-Toluidine
