觸媒濕式過氧化反應處理含酚廢水之研究

Study on Catalytic Wet Peroxide Oxidation of Phenol by Metal-Supported Catalyst

本研究利用了型三氧化二鋁(γ-Al2O3)作為擔體，合成各種不同金屬觸媒，在添加過氧化氫之狀態下進行觸媒濕式過氧化反應(Catalytic Wet Peroxide Oxidation, CWPO)，藉由分析紛轉化率與COD去除率，評估各種觸媒對於含酚廢水濕式過氧化反應之催化效能。本研究所合成之金屬觸媒包括Cu、Mn、Co、Cr和Ni，添加量固定為5wt%。研究結果顯示以銅合成之觸媒作為觸發過氧化氫生成氫氧白由基(free radicals, OH•)之效果最佳，在反應條件為：酚濃度500mg/L、觸媒添加量1.0g/L、過氧化氫添加量1200mg/L、起始pH=3、反應溫度40℃時，5wt% Cu/γ-Al2O3觸媒反應三小時之酚轉化率及COD去除率分別約80%及32%；為了增加觸媒之催化活性與耐用性，本研究合成含浸量為15-5 wt%之Ce-Cu/γ-Al2O3觸媒，在觸媒添加量1.5g/L，過氧化氫1200ppm，反應溫度40℃，起始pH=3，酚濃度500mg/L之反應情況下，對酚之去除效率在3小時內叫達90%以上，化學需氧量的去除率亦可達38%。使用過後之Ce-Cu/γ-Al2O3觸媒經再生後，重複測試並與新鮮觸媒作比較，其催化效率雖然降低，但再生效能優於銅擔體觸媒，故鈰－－銅擔體觸媒比銅觸媒有較優之活性與耐用性。

Catalysts with various metals (Cu、Mn、Co、Cr and Ni) supported on γ-Al203 were used to implement the catalytic wet peroxide oxidation (CWPO) of phenolic wastewater. Via rates of phenol conversion and COD removal, performance of the catalysts was evaluated to screen for the optimal one. With fixed amount of metal (5 wt%), the Cu/γ-Al2O3 performed best because it catalyzes H2O2 to create effective free radicals. At the conditions of 500 mg/L phenol concentration, 1.0 g/L catalyst loading, 1200 mg/L H2O2, initial pH 3 and 40℃, the phenol conversion and COD removal after 3 hrs reaction were 80% and 32%, respectively. On the other hand, the 15-5 wt% Ce-Cu/γ-Al2O3 prepared in this study was found to be more active and durable than Cu/γ-Al2O3 catalyst tested. At the conditions of 1.5 g/L catalyst loading, 1200 mg/L H2O2, initial pH 3 and 40℃, 500 mg/L phenol could attain 90% phenol conversion and 38% COD removal after 3 hours CWPO reaction. Though the activity of regenerated catalysts, including Ce-Cu/γ-Al2O3 and Cu/γ-Al2O3 catalysts, was lower than that of fresh ones, it was found that regenerated Ce-Cu/γ-Al2O3 had higher performance than the regenerated Cu/γ-Al2O3 catalyst tested.