固定化光觸媒於旋轉盤反應器降解亞甲藍

Degradation of Methylene Blue in Spinning Disk Reactor by Immobilized Photocatalyst

吳豐州(Fong-Chou Wu)

指導教授 ： 陳昱劭

中原大學/工學院/化學工程研究所/碩士(2019年)

https://doi.org/10.6840/cycu201900764

摘要

本研究於旋轉盤反應器中利用固定化光觸媒連續降解亞甲基藍，其中固定化催化劑為二氧化鈦薄膜，以溶膠凝膠法及旋轉塗佈法製備，探討二氧化鈦塗佈層數、光照強度、轉速、液體流率、染料濃度及過氧化氫濃度對於光催化降解的變化。計算不同操作條件下液體在盤面上的滯留時間及液膜厚度，並探討對於光催化降解效率的影響，最後再與文獻中的光催化反應器進行比較。
實驗結果顯示，在高瓦數之UV光源的情況下得到較好的降解效率，降解效率隨觸媒塗佈層數增加而上升，隨液體流率上升而下降，在100~700 rpm之間，轉速對於降解效率影響幅度不大，普遍在300 rpm有最好效果。當染料濃度上升時，會降低光穿透效果，使降解效率減少。而添加過氧化氫的情況下，降解效率隨H2O2濃度上升而增加，在濃度高於300 mg/L時，因過多的H2O2與羥基自由基反應造成降解效率減少。利用Beer’s law 與擬一階反應模型，可對實驗結果進行擬合，得到良好的相關性。
在各個操作條件的結果得到，在三層二氧化鈦塗佈、UV光源50 W、轉速300 rpm、液體流率20 mL/min、過氧化氫濃度300 mg/L時，降解效率高達91.9%，此結果顯示，旋轉盤反應器在連續式光催化反應中具有相當高的潛力。

關鍵字

旋轉盤反應器 ； 二氧化鈦 ； 光催化 ； 亞甲基藍

並列摘要

This study, used immobilized titanium dioxide film as photocatalyst which was prepared by sol-gel method and spin coating to degrade methylene blue in spinning disk reactor by continue system. The effects of coating layers of titanium dioxide, light intensity, rotation speed, liquid flow rate, dye concentration and hydrogen peroxide concentration on photocatalytic degradation were investigated. Moreover, the residence time and liquid film thickness on the disk were calculated by different operating conditions, and their effects of the photocatalytic degradation efficiency was investigated. At last, the results ware compared with those of other reactor in the literature.
The result revealed that the degradation efficiency increased with increasing the light intensity and the coating layers but decreasing with liquid flow rate. Although, the effect of the rotated speed was not obvious between 100 to 700 rpm, the efficiency at 300 rpm was the best. Moreover, the degradation efficiency decreased with the increase of MB concentration, which was caused by the reduction of the light penetration efficiency. Furthermore, H2O2 addition could improve the degradation efficiency. However, H2O2 could react with hydroxyl radical to decrease the efficiency when the H2O2 concentration was higher than 300 mg/L. Finally, the experimental results could be fitted by Beer’s law and pseudo-first-order reaction model.
The optimum degradation efficiency was up to 91.9% at three layers TiO2 coating, 50 W UV light, 300 rpm rotation speed, 20 mL/min liquid flow rate and 300 mg/L H2O2. Thus, spinning disk reactor has high potential for continuous photocatalytic reaction.

並列關鍵字

spinning disk reactor ； titania ； photocatalysis ； methylene blue

參考文獻

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