摘要本研究探討以陶瓷載體承載過渡金屬作為具催化功能之氧化觸媒，以不同金屬種類與金屬濃度比例，製備鐵、銅、錳金屬成各型觸媒，以填充床批式反應器進行臭氧催化降解含酚溶液，並以高壓液相層析儀(HPLC)與總有機碳分析儀(TOC)測定水中酚轉化率及水中總有機碳去除率，並使用感應耦合電漿原子發射光譜儀(ICP)分析實驗過程中金屬溶出情形。研究中以螢光分析儀探討臭氧催化氧化反應器催化產生自由基之活性，以比表面積分析儀(BET)分析陶瓷觸媒球之孔隙特性，並探討在不同的金屬及濃度含浸下對於孔隙體積之改變；以掃描式電子顯微鏡(SEM)觀察陶瓷觸媒球表面結構以及金屬分佈狀態，再以X射線能量分散光譜儀分析觸媒球體表面金屬元素組成。研究顯示，不論銅、鐵或錳型觸媒在使用批次濕式臭氧催化氧化系統中皆有顯著的催化與氧化性，在500mg/L含酚溶液之酚轉化率幾乎到達99%，其中銅型觸媒之TOC去除優於錳型與鐵型觸媒，且在溶液不同酸鹼值中顯示出在pH 8條件下TOC去除率為最佳值。催化反應明顯受到溶液中酸鹼值影響，雖然高pH值能使臭氧更容易分解產生氫氧自由基由於pH值的增加會造成觸媒表面的帶電性改變進而造成吸附效應的改變，反而在較弱鹼性pH8下對於含酚之廢水氧化效果優於pH9與pH10，在長時間與高濃度試驗中顯示在添加觸媒去除TOC效果明顯優於無添加觸媒，且由螢光分析儀分析自由基生成量可得知，本實驗之氧化機制是以觸媒催化氫氧自由基進行氧化。本研究在低pH值時會因氧化反應時溶液酸鹼值變化造成觸媒溶出之現象，在同一金屬濃度pH8時，其溶出明顯高於pH9與pH10，本研究之陶瓷觸媒在應用於批次濕式臭氧催化氧化含酚溶液可獲得99%以上的酚轉化率與80%以上的TOC去除率。 AbstractThe purpose of this study is to prepare ceramic supported metal oxide catalysts and apply for catalytic ozonation of phenol in wastewater. Those catalysts were embedded different transition metals with various immersing concentration and the catalytic ozonation of wastewater were carried out in a semi-batch packing-bed reactor. The performance of catalytic ozonation was evaluated by considering the degradation of phenolic material and total organic carbon (TOC) removal in the ozonation. The ICP spectra measurements were used to quantify the dissolute metal ion concentration from the catalyst and it was also correlated to the life time of catalyst. The activities of catalysts were determined by the measurement of free radical concentration by florescent method. The pore and characteristics of surface properties of catalysts were analyzed by the analysis of BET measurements. All the pore properties, SEM observations and active metal distribution on the surface of catalyst were correlated with the ozonation activity of catalysts in this study. It was found that the high ozonation activities of ceramic catalyst with various transition metals embedded in ceramic support were confirmed. Over 99% phenol conversions in the catalytic ozonation were found in all cases of catalysts in ozonation with 500mg/L phenol in the wastewater. It was also found that the TOC removal of copper type catalyst showed superior performance to manganese and iron type catalysts in the ozonation treatment. Operating conditions strong affected the activity of ozonation of ceramic supported metallic catalysts and alkaline environment presented a higher activity of catalyst than the acidic condition in the ozonation. The best condition of ozonation is under pH 8 to generate much more hydroxide radical than the higher pH condition. The Fluorescent technology was used to quantitate the free radical of hydrogen peroxide. In this study, it is confirmed that the catalytic ozonation is enhanced by the ceramic supported catalysts whose activity is dominated by the nature of transition metal and loading concentration in the catalyst. A high catalytic ozonation performance was observed in this investigation and an over 99% phenol conversion and 80% TOC removal was achieved by under the suitable condition in ozonation.
