A novel UV/NTFC photocatalytic reactor with regeneration system
|關鍵字:||奈米零價鐵;二氧化鈦;光催化反應器;奈米顆粒回收再生;nano zero-valent iron;titanium dioxide;photocatalytic reactor;regeneration of nanoparticles|
|摘要:||奈米級零價鐵及二氧化鈦為近年來被廣泛研究與應用於處理環境污染物之材料。本研究室目前已發展出奈米級二氧化鈦/零價鐵複合材料(nanoscale TiO2/Fe0 composite, NTFC)，先前之研究顯示NTFC能有效的降解偶氮染料及硝酸鹽等污染物，其可改善二氧化鈦及零價鐵於應用上之限制。近年來亦有文獻指出，於二氧化鈦複合光觸媒處理污染物過程中，其處理環境之操作參數對於光觸媒處理污染物之效能亦具有極大之影響力。
Nano-zero-valent iron (nFe0) and titanium dioxide (TiO2) are valid catalysts for the treatment of organic pollutants in wastewater. In previous studies, a novel TiO2/Fe0 composite (NTFC) material was prepared to overcome the restriction of utilizing nFe0 and TiO2. The NTFC can be successfully applied for degrading azo-dye in water. Also, many studies have indicated the significant impact of operating parameters on using the photocatalysts. The aim of this study was to develop a UV/NTFC pilot system to investigate the reductive ability of NTFC, the feasibility for azo-dye removal, as well as the optimization of operational conditions. In this work, the reactions departed into two parts, batch and continuous flow tests. The batch test adjusted the initial pH and ionic strength as the operating conditions. The continuous flow test proceeded under the optimal condition of batch test. Moreover, the catalysts were collected by the magnet after the reaction. The UV-Vis spectrometer and total organic compound (TOC) were used as parameters to evaluate the feasibility of azo-dye removal. Also, the colloidal particles of NTFC in UV/NTFC pilot system were determined by measuring their zeta potentials and particle size distributions. By monitoring pH, ORP and dissolved oxygen, it suggests the reaction follows a comprehensive mechanism of reduction and oxidation. The decolorization and TOC removal can be reduced by the batch test under acidic condition. Nevertheless, the decolorization and TOC removal rate could effectively decrease at different ionic strengths of solutions. In the continuous flow test, the result shows the catalysts can be regenerated by addition of the H2O2. And the reaction by regenerated NTFC can sustain for 24 hrs. In conclusion, the UV/NTFC pilot system can not only be successfully applied for the treatment of high color wastewater under acidic condition but also effectively regenerate the catalyst particles.
|Appears in Collections:||Thesis|