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  • 學位論文

銅型活性碳催化過硫酸鹽應用於染料RB19降解之研究

Persulfate Degradation of Dye Reactive Blue 19 Catalyzed by Copper-Impregnated Activated Carbon

指導教授 : 駱尚廉

摘要


過硫酸鹽經活化後可產生具高反應性之硫酸根自由基(SO4˙-)與氫氧根自由基(HO˙),可氧化有機物,且於酸性pH環境下,SO4˙-為優勢自由基;於中性pH環境下,SO4˙-可與氫氧根離子(OH-)進行自由基轉換,生成HO˙;於鹼性pH環境下,HO˙則為主要之自由基。 然而,過硫酸鹽於常溫中十分穩定,對污染物的氧化反應緩慢,因此,本研究利用銅改質後之活性碳催化過硫酸鹽,進行RB19之降解探討,並藉由改變過硫酸鹽劑量、銅批覆量、銅型活性碳劑量、初始溶液pH(3、5、7、9及11)以及反應溫度(25、35及45℃),比較過硫酸鹽單系統、銅型活性碳單系統及銅型活性碳催化過硫酸鹽之結合系統對染料降解能力之差異。 實驗結果顯示,於過硫酸鹽單系統時,提高過硫酸鹽添加量及溫度皆有助於提升RB19之去除率,而在以HO˙為優勢自由基之高pH條件下,染料之降解效果較好。銅型活性碳之物化分析結果顯示,經鍛燒後可使批覆之銅還原為零價銅的狀態,提供更高的催化能力,但批覆過量銅會降低活性碳之表面積,減少吸附與活性位置,造成RB19去除率的下降,經由實驗證實最佳之銅批覆量為1%,且其對染料的吸附機制可符合Bangham’s Model與非酸性環境下之Intra-particle Diffusion Model。此外,增加添加量、鹼性pH環境與提高溫度皆可提高RB19的降解。 銅型活性碳催化過硫酸鹽的結合系統中,染料去除率隨著過硫酸鹽的劑量及溫度的提升而增加,於不同pH下之效果為:pH 11 > pH 3 > pH 5 > pH 9 > pH 7,銅批覆量之結果與銅型活性碳單系統相同,皆於1 %批覆量時達到最佳降解效果。本實驗最佳操作條件為PS/RB19=25,1% Cu/AC添加量為1 g/L,pH=11並控溫於45℃,經一小時反應後,RB19的去除率可達96.79 %,且結合系統之活化能Ea= 56.14 KJmol-1。 於室溫下,比較單系統與結合系統之實驗結果,可觀察出明顯的加成效果。結合系統亦顯示高溫及鹼性環境下可提高其去除率,恰符合染料廢水具有之高溫及高pH特性,可見以銅型活性碳催化過硫酸鹽之方法適合用於降解含RB19之染料廢水。

並列摘要


Sodium persulfate can be thermally or chemically activated to produce sulfate free radicals (SO4˙-) and hydroxyl free radicals (HO˙), which have very powerful oxidation ability for pollutants. It has been demonstrated that under acidic condition, SO4˙- is the dominant oxidant radical species;under neutral condition, the SO4˙- can proceed reaction with hydroxyl ions to generate HO˙;under alkaline condition, HO˙is the major oxidant radical species. However, Persulfate is stable at the ambient temperature and oxidate pollutants slowly. In this study, copper-impregnated activated carbon was used as the activator of PS to accelerate the degradation of anthraquinone dye RB19 by changing the ratio of copper impregnated, dosages of persulfate and Cu/AC, initial solution pH (3,5,7,9 and 11) and temperature (25,35 and 45℃). In addition, the differences of degradation potential between PS, Cu/AC and Cu/AC+PS wereinvestigated. In PS system, increase the dosage of PS and temperature can improve the removal efficiency of RB19. The alkaline condition is more favorable to the RB19 degradation due to the production of dominant radical species HO˙ which has higher redox potential. Physical and chemical analysis of Cu/AC showed that after calcinations, impregnated copper turned into zero valent state which can provide higher catalytic ability. Impreganating excess copper decreased the specific surface area of AC. With the decrease of adsorption and activation position, the removal ratio of RB19 would reduce. The experiments confirmed that the optimum copper impregnated ratio was 1%. The removal process of RB19 followed Bangham’s Model and Intra-particle Diffusion Model in Cu/AC system. In Cu/AC+PS system, the removal efficiency of RB19 increased with the enhancement of PS dosage and temperature. The effect of pH on RB19 degradation rate was pH 11 > pH 3 > pH 5 > pH 9 > pH 7. The optimum amounts of impreganated copper were the same with Cu/AC system; all get the best degradation efficiency at the impregnated amounts of 1%. The removal efficiency of RB19 can reach to 96.79% under optimum operational conditions of PS/RB19=25, 1 g/L 1% Cu/AC, pH=11 and 45℃ after one hour of reaction. Under the combined system, the reaction activation energyEa= 56.14 KJmol-1. Compare the experimental results of the single systems with those of the combined system at the ambient temperature, a significant synergistic effect can be observed. The combined system displays higher removal at a high temperature and in the alkaline environment, which is exactly in line with the characteristics of dye wastewater:the high temperature and high pH. It is thus evident that this method is suitable for the degradation of dye wastewater containing RB19.

並列關鍵字

RB19 Anthraquninone Dye Persulfate Activated Carbon Copper Catalyze AOPs

參考文獻


[74]王安琪. (2013). 鐵型活性碳催化過硫酸鹽應用於染料RB19之降解.
[4]He, Z., Lin, L., Song, S., Xia, M., Xu, L., Ying, H., & Chen, J. (2008). Mineralization of C.I. Reactive Blue 19 by ozonation combined with sonolysis: Performance optimization and degradation mechanism. Separation and Purification Technology, 62(2), 376-381. doi: 10.1016/j.seppur.2008.02.005
[5]Ozcan, A., Omeroglu, C., Erdogan, Y., & Ozcan, A. S. (2007). Modification of bentonite with a cationic surfactant: An adsorption study of textile dye Reactive Blue 19. J Hazard Mater, 140(1-2), 173-179. doi: 10.1016/j.jhazmat.2006.06.138
[6]Carneiro, P., Nogueira, R., & Zanoni, M. (2007). Homogeneous photodegradation of C.I. Reactive Blue 4 using a photo-Fenton process under artificial and solar irradiation. Dyes and Pigments, 74(1), 127-132. doi: 10.1016/j.dyepig.2006.01.022
[7]Song, S., Ying, H., He, Z., & Chen, J. (2007). Mechanism of decolorization and degradation of CI Direct Red 23 by ozonation combined with sonolysis. Chemosphere, 66(9), 1782-1788. doi: 10.1016/j.chemosphere.2006.07.090