- 學位論文
黑雲母催化過硫酸鹽及芬頓反應降解直接性偶氮染料廢水之研究
Biotite Catalyzed Persulfate and Fenton’s Reaction for Degradation of Direct Azo Dyes
摘要
本研究利用天然鐵氧礦物黑雲母(Biotite，BT)催化芬頓(Fenton)反應及活化過硫酸鹽(Persulfate)反應，並以超音波(US)及熱輔助降解直接性偶氮染料DB71、DV51、DY27。主要目的為探討Fenton程序及Persulfate氧化程序之各影響因子對染料脫色之影響。藉由檢測鐵離子殘餘量、COD去除率及自由基釋出情形(•OH、SO─4•)，觀察在不同程序中染料在氧化反應過程中的變化及降解效果。研究結果顯示，超音波及熱輔助會提升氧化效能。Fenton反應最適合條件：dye 2.5×10-5 M、biotite 0.2 g/L、H2O2 1×10-3 M、pH 3.0、60ºC。Persulfate反應最適合條件：dye 2.5×10-5 M、biotite 0.2 g/L、PS 1×10-3 M、pH 3.0、60ºC。雙偶氮的DV51在Fenton程序及Persulfate氧化程序脫色速率皆是最佳，而DY27雖然在BT/H2O2/60ºC程序及BT/PS/60ºC程序中反應60 min後ADMI可遠低於法規550，但其脫色速率反而是最差。研究證實利用天然鐵氧礦物黑雲母能有效降解直接性偶氮染料，在超音波及高溫條件下真色色度皆能降至放流水標準ADMI 550以下。根據自由基檢測結果，•OH與SO─4•分別是Fenton程序及Persulfate氧化程序中之主要自由基。
並列摘要
In this study, natural ferrite mineral biotite (BT) was used to catalyze the Fenton's reaction persulfate reaction. Ultrasound (US) and heat were used as enhancement tools for degradation of direct azo dyes, namely DB71, DV51, and DY27. The effects of operating parameters affecting Fenton and persulfate process in decolorization of dyes were evaluated. In the experimental setup, concentration of iron ions, COD, identification of major reactive radicals, and color depletion as a function of time were determined as to observe the oxidation power of different procedures. The results showed that ultrasonic and heat are capable of enhancing oxidation efficiency. The most suitable conditions of Fenton's reaction for completely decolorization of dye concentration at 2.5×10-5 M are biotite 0.2 g/L, H2O2 1×10-3 M, pH 3.0, and 60 ºC. The most suitable conditions of persulfate reaction for completely decolorization of dye concentration at2.5×10-5 M are biotite 0.2 g/L, PS 1×10-3M, pH 3.0, and 60 ºC. Among the treated dyes using Fenton's process and the persulfate oxidation process, the double azo dye DV51 achieved the best decolorization efficiency. Although the rate of decolorization of A DY27 is lower than that of DB71 and DV51, the treated ADMI meet the effluent standard after 60 minutes treatment by BT/H2O2/60 ºC and BT/PS/60 ºC process. This research proves that the use of biotite can effectively degrade direct azo dyes. ADMI can be reduced to 550 below the effluent criteria upon the input of ultrasonic and heat in the process. Findings of radical identification indicated that •OH and SO─ 4• are the major radicals responsible in Fenton and persulfate process, respectively.