| 摘要: | 本研究目的係利用半批次式反應槽，探討蒽醌染料水溶液的臭氧化降解，並評估不同的臭氧化操作參數包含染料初始濃度、臭氧供應流率和初始pH，對色度、染料、TOC的去除效能。同時，鑑定分析染料降解過程可能產生的中間產物，探討染料可能的臭氧化降解途徑。最後則評估染料水溶液藉臭氧化所提升的生物可分解性。 實驗結果顯示，反應性藍色19號(Reactive Blue 19, RB-19)可藉臭氧化處理而降解。在臭氧化實驗中，色度與染料之去除，均比TOC去除快且完全。不過，提高染料初始濃度，會顯著降低染料的去除效率。此外，增加臭氧供應流率則對色度、染料、TOC之去除，均有正面的影響，特別是對TOC的去除最為明顯。在初始pH影響方面，色度去除的速率常數和效率，在初始pH為酸性的條件下達到最高。然而染料和TOC的去除，則以初始pH為鹼性的條件較有效率，此可能係受到氧化力較強且無選擇性的氫氧自由基氧化反應所致。 RB-19經直接臭氧氧化反應後，由UV/VIS和FTIR光譜分析的結果顯示，其蒽醌結構、氮基連結基和氨基受到臭氧所破壞。LC-MS與GC-MS分析的結果則分別指出，一些有機酸(例如臨苯二甲酸)和1,3-吲酮(1,3-indanone)可能是主要的降解產物。因此，RB-19可能的降解途徑，視氨基或氮基連結基何者首先被臭氧破壞而定。 基本上，臭氧化處理RB-19染料水溶液具有提高其BOD5/COD比值的潛力，因此可提升生物可分解性。另一方面，臭氧化處理亦有降低染料水溶液的Microtox毒性，和增加污泥比攝氧率(SOUR)的效果。由生物降解篩選試驗的驗證顯示，臭氧化處理可大幅提高生物降解RB-19染料水溶液的DOC去除率。 The objective of this study was to investigate the degradation of anthraquinone dyes in aqueous solution by ozonation using a semi-batch reactor. The effects of various operating parameters, such as initial dye concentrations, ozone feed rates and initial pH, on performance of color, dye, and TOC removal were evaluated. Also, possible dye degradation products were identified to investigate degradation pathways. Finally, the biodegradability enhancement of dye solution by ozonation was assessed. The experimental results showed that Reactive Blue 19 (RB-19) could be degraded by ozonation. The color and dye removal were more rapid and complete than TOC removal in all ozonation tests. However, increasing the initial RB-19 concentration had significant effect on decreasing the elimination of RB-19. In addition, increasing ozone feed rates had all positive effects on color, dye and TOC removal, particularly on TOC diminution. Also, the rate constant and efficiency of color removal were highest at initial acidic pH condition, but dye and TOC removal were more effective at the basic pH value likely due to more powerful and non-selective hydroxyl radical oxidation. The results of UV/VIS and FTIR spectra showed that the anthraquinone structures, nitrogen linkages and amino groups of RB-19 were destroyed under direct ozone reaction. The identification by LC-MS and GC-MS analyses indicated that some organic acids (e.g., phthalic acids) and 1,3-indanone could be the primary degradation products, respectively. Thus, the possible degradation pathways, which count on the initial destruction of either amino groups or C–N–Aromatic linkages, were proposed Basically, ozonation was confirmed to have potential to increase BOD5/COD ratio of RB-19 solution. On the other hand, ozonation also decreased Microtox toxicity and increased SOUR of RB-19 solution. The enhanced biodegradability was validated by screen tests, which revealed an improved DOC removal by biodegradation. |
