鐵型活性碳催化過硫酸鹽應用於染料RB19之降解

Degradation of dye Reactive Blue 19 by Iron-Activated Carbon Catalyzed Persulfate

王安琪(An-Chi Wang)

指導教授 ： 駱尚廉

國立臺灣大學/工學院/環境工程學研究所/碩士(2013年)

https://doi.org/10.6342/NTU.2013.10846

摘要

過硫酸鹽因其會產生高反應性的硫酸根自由基（〖SO_4〗^(•-)）與氫氧根自由基（•OH）而具有氧化有機物的能力，為高級氧化處理中新興的強氧化劑。未活化的過硫酸鹽對污染物的反應較慢，無法快速氧化有機物，因此本研究利用鐵改質後的活性碳催化過硫酸鹽，進行染料RB19之降解，並藉由改變鐵披覆量、過硫酸鹽劑量、鐵型活性碳劑量、溶液初始pH值（3、7、10）以及反應溫度（25、35、45 ℃），比較過硫酸鹽系統、鐵型活性碳系統、鐵型活性碳催化過硫酸鹽之結合系統對染料去除能力差異。
實驗結果顯示在過硫酸鹽系統當中過硫酸鹽加入劑量、溫度的提高都有助於RB19去除率的提升，而在高pH條件下有利於強氧化還原能力的•OH生成，染料降解效果較好。鐵型活性碳的物化分析結果顯示，經過鐵披覆的處理之後，會降低其比表面積，減少吸附及活性位置，造成RB19去除率的降低；另外此單系統當中最佳鐵披覆量為1%，且其對染料的去除機制可符合Intraparticle diffusion model及Pseudo-second-order kinetic model。
鐵型活性碳催化過硫酸鹽的結合系統中，染料去除率會隨著過硫酸鹽劑量、溫度的增加而上升，但鐵型活性碳的披覆量與劑量則並非越多越好，原因是加入過量鐵型活性碳會使Fe2+增加過多，短時間內消耗掉〖SO_4〗^(•-)，抑制反應進行。本實驗的最佳操作條件為PS/RB19=50，1%Fe/AC加入量為0.5 g/L，溶液pH為10並控溫在45 ℃，反應時間一小時過後，RB19的去除率可達95.68%。
在室溫下，藉由單系統與結合系統比較結果可觀察出明顯的加成效果，因此可證明本系統非常適合用於處理染料廢水，在不易加溫的條件下，只要利用觸媒的添加，即可有利於過硫酸鹽的催化。

關鍵字

催化 ； 過硫酸鹽 ； 高級氧化 ； 活性碳 ； 蒽醌染料 ； 鐵

並列摘要

Persulfate can be thermally or chemically catalyzed to produce sulfate and hydroxyl free radicals which have very powerful oxidation ability. These advantages of being the strongest oxidants make persulfate a promising choice among the advanced oxidation processes (AOPs) for treating organic pollutants. Reactions of persulfate are generally slow at ambient temperature, so we use Iron-modified activated carbon to be the activator of PS to accelerate the degradation of anthraquinone dye RB19. In this study, we investigated the effect of iron coated ratios, dosages of persulfate and Fe/AC, initial solution pH(3, 7 and 10), temperature(25, 35 and 45 ℃) on the RB19 removal. In addition, the difference of the degradation potential between three systems: PS, Fe/AC, Fe/AC+PS were also investigated.
In PS system, the removal efficiency of RB19 increased with higher PS dosage and higher temperature. The alkaline pH is more favorable to the RB19 degradation because this condition will make PS decomposed to produce •OH which has higher redox potential. The surface characterization of Fe/AC showed that the specific surface area of AC decreased with more iron coated. With the decrease of adsorption and activation position, the removal ratio of RB19 would reduce. Furthermore, the optimum iron coated ratio was 1% and the removal process followed the Intraparticle diffusion model or Pseudo-second-order kinetic model in Fe/AC system.
In Fe/AC+PS system, the removal efficiency of RB19 increased with higher PS dosage and higher temperature. But excessive dosage of Fe/AC would inhibit the catalytic ability because Fe2+ will consume the produced sulfate radicals. There existed a remarkable synergistic effect in combined system which can remove 95.68% of RB19 under optimum operational conditions of 0.5g/L 1%Fe/AC, PS/RB=50, pH 10, 45℃.

並列關鍵字

Catalyze ； Persulfate ； AOPs ； Activated carbon ； Anthraquninone dye ； Iron

參考文獻

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