UV/H₂O₂, UV/TiO₂/H₂O₂, Photo-Fenton 산화방법에 의한 Citric Acid의 분해특성
Degradation Characteristics of the UV/H₂O₂ UV/TiO₂/H₂O₂ and Photo-Fenton Oxidation for Degradation of Citric Acid
- 발행기관 亞州大學校 大學院
- 지도교수 趙舜行
- 발행년도 2005
- 학위수여년월 2005. 2
- 학위명 석사
- 학과 및 전공 일반대학원 공학계열
- 본문언어 한국어
초록/요약
화학세정폐수에 함유되어 있는 citric acid의 효율적인 처리방안을 수립하기 위해 UV/H₂O₂, UV/TiO₂/H₂O₂, Photo-Fenton 산화방법을 이용하여 각각 citric acid의 제거효율 및 그에 따른 전력소비량을 평가하였다. 이를 위하여 실제폐수에 함유되어 있는 citric acid의 농도를 분석하고 이를 근거로 인공폐수를 조제하여 실험에 사용하였으며, 각 산화방법별로 반응에 영향을 미치는 기초인자의 변화에 따른 처리효율을 조사하여 최적 처리조건을 도출하였다. 그 결과 조사된 최적 처리조건에서 UV/H₂O₂, UV/TiO₂/H₂O₂, Photo-Fenton 산화방법을 이용한 citric acid의 제거효율은 각각 95.5%, 92.3%, 91.5%로 조사되었으며, 그에 따른 전력소비량은 11.26 kWh/㎥, 3.85 kWh/㎥, 0.799 kWh/㎥으로 조사되었다. 이 결과에 의하면 세 가지 광화학적 산화방법 모두 유기물질이 90%이상 제거되어 citric acid의 분해에 효과적인 것으로 판단되었다. 그러나 Photo-Fenton 산화방법이 다른 방법에 비해 처리에 소요되는 반응시간이 짧은 것으로 나타났다. 또한 광화학적 산화방법의 운영비를 결정짓는데 중요한 요소인 전력소모량 측면에서도 Photo-Fenton 산화방법이 다른 방법에 비해 우수한 것으로 조사되어 본 연구에서 비교하는 세 가지 방법 중 citric acid 처리에는 Photo-Fenton 방법이 효율적인 면과 경제성면에서 가장 적합한 처리기술로 결론지을 수 있었다.
more초록/요약
To establish the efficient treatment technology of chemical cleaning wastewater from power plant, several Photo-Chemical Oxidations (UV/H₂O₂, UV/TiO₂/H₂O₂, Photo-Fenton oxidation) were investigated. Treatment efficiencies and the electrical energy requirements based on the EE/O parameter (the electrical energy required per order of pollutant removal in 1 ㎥ wastewater) were evaluated. TOC removal efficiencies by UV/H₂O₂, UV/TiO₂/H₂O₂, Photo-Fenton oxidation at the optimum conditions were 95.5%, 92.3%, 91.5%, respectively. The electrical energy requirements of UV/H₂O₂, UV/TiO₂/H₂O₂, Photo-Fenton oxidation were 11.26 kWh/㎥, 3.85 kWh/㎥, 0.799 kWh/㎥, respectively. From these results, it could be concluded that all of the three oxidation processes were effective for the degradation of citric acid. Considering the treatment efficiency and economical aspect, photo-Fenton oxidation was the most efficient treatment process among the three processes tested.
more목차
목차
표목차 = ⅰ
그림목차 = ⅲ
국문요약 = ⅵ
Ⅰ. 서론 = 1
Ⅱ. 이론적 고찰 = 3
2.1. 광화학적 산화방법 (Photochemical Oxidation) = 3
2.1.1. VUV Photolysis = 6
2.1.2. UV/Oxidation Processes = 8
2.1.3. Photo-Fenton Oxidation Process = 9
2.1.4. TiO₂ Photocatalytic Oxidation Process = 12
2.2. 화학세정 = 14
2.2.1. 무기산 세정제 = 15
2.2.2. 유기산 세정제 = 15
2.2.3. 기타 착화제 = 16
Ⅲ. 실험장치 및 방법 = 17
3.1. 시료 = 17
3.2. 실험장치 = 17
3.3. 실험방법 = 19
3.3.1. UV/H₂O₂ 산화 = 19
3.3.2. TiO₂ 광촉매 산화 = 21
3.3.3. Photo-Fenton 산화 = 23
Ⅳ. 실험결과 = 25
4.1. UV/H₂O₂ 산화 = 25
4.1.1. UV 및 H₂O₂에 의한 분해특성 = 25
4.1.2. pH 변화에 따른 분해특성 = 27
4.1.3. 과산화수소 주입량의 변화에 따른 분해특성 = 33
4.1.4. UV/H₂O₂ 산화반응시 생성되는 유기산의 영향 = 36
4.2. UV/TiO₂/H₂O₂ 산화 = 38
4.2.1. pH 변화에 따른 분해특성 = 38
4.2.2. 과산화수소 주입량의 변화에 따른 분해특성 = 45
4.2.3. TiO₂ 광촉매 주입량의 변화에 따른 분해특성 = 50
4.3. Photo-Fenton 산화 = 54
4.3.1. Fe^(2+) 주입량 변화에 따른 분해특성 = 54
4.3.2. 과산화수소 주입량 변화에 따른 분해특성 = 56
4.4. 광화학적 산화방법의 전력소모량 평가(EE/O) = 58
4.4.1. UV 강도 측정 = 58
4.4.2. 전력소모량 비교 = 62
Ⅴ. 결론 = 65
참고문헌 = 67
Abstract = 73
목차
List of Tables
Table 1. Oxidation potential of several oxidants in water = 4
Table 2. Rate constants for O₃ and OH· reaction with organic compounds in Water = 5
Table 3. Experimental conditions of UV/H₂O₂ oxidation = 20
Table 4. Experimental conditions of TiO₂ photocatalytic oxidation = 22
Table 5. Experimental conditions of Photo-Fenton oxidation = 24
Table 6. Degradation characteristics of citric acid by UV/H₂O₂ oxidation at various pH = 28
Table 7. Degradation characteristics of citric acid by UV/TiO₂/H₂O₂ oxidation at various pH = 40
Table 8. Degradation characteristics of citric acid by UV/TiO₂/H₂O₂ oxidation at various H₂O₂ dosage = 47
Table 9. Degradation characteristics of citric acid by UV/TiO₂/H₂O₂ oxidation at various TiO₂ dosage = 51
Table 10. Quantum yields of ferrous production from potassium ferrioxalate = 61
Table 11. Comparison of UV/H₂O₂, UV/TiO₂/H₂O₂, Photo-Fenton oxidation at respective optimum conditions = 63
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List of Figures
Fig. 1. UV spectrum = 6
Fig. 2. Generally accepted mechanism of the VUV-induced oxidation = 7
Fig. 3. Scheme of chemical reaction in the photo-Fenton reaction = 11
Fig. 4. Simplified TiO₂ photocatalytic mechanism = 13
Fig. 5. Schematic diagram of photochemical oxidation reactor = 18
Fig. 6. Change of TOC removal efficiency by UV, H₂O₂, UV/H₂O₂ oxidation = 26
Fig. 7. Change of TOC removal efficiency by UV/H₂O₂ oxidation at various pH = 29
Fig. 8. Concentration profile of CO₂ in the solution by UV/H₂O₂ oxidation at various pH = 30
Fig. 9. Relationship between TOC removal and H₂O₂ consumption at various pH in the UV/H₂O₂ oxidation = 32
Fig. 10. Change of TOC removal efficiency by UV/H₂O₂ oxidation at various H₂O₂= 35
Fig. 11. Scheme of citric acid structure = 36
Fig. 12. Change of various organic acid concentration by UV/H₂O₂ oxidation for degradation of citric acid = 37
Fig. 13. Change of TOC removal efficiency by UV/TiO₂/H₂O₂ oxidation at various pH = 41
Fig. 14. Change of adsorption capacity and TOC removal efficiency by TiO₂ photocatalytic oxidation at various pH = 42
Fig. 15. Concentration profile of CO₂ in the solution a by TiO₂ photocatalytic oxidation at various pH = 43
Fig. 16. Relationship between TOC removal and H₂O₂ consumption at various pH by TiO₂ photocatalytic oxidation = 44
Fig. 17. Change of TOC removal efficiency by TiO₂ photocatalytic oxidation at various H₂O₂ dosage = 48
Fig. 18. Relationship between TOC removal and H₂O₂ consumption at various H₂O₂ dosage by TiO₂ photocatalytic oxidation = 49
Fig. 19. Change of TOC removal efficiency at 600 minute illumination with various TiO₂ dosage in TiO₂ photocatalytic oxidation = 52
Fig. 20. Relationship between TOC removal and H₂O₂ consumption at various TiO₂ dosage by TiO₂ photocatalytic oxidation = 53
Fig. 21. Change of TOC removal efficiency by photo-Fenton oxidation at various Fe^(2+) dosage = 55
Fig. 22. Change of TOC removal efficiency by photo-Fenton oxidation at various H₂O₂ dosage = 57
Fig. 23. The extinction coefficient for ferrous 1,10-phenanthroline complex = 60
Fig. 24. Change of TOC removal efficiency by three photochemical oxidation at optimum condition, respectively = 64
