표제지
목차
ABSTRACT 12
제1장 서론 15
제1절 연구배경 15
제2절 연구목적 16
제2장 이론적 고찰 17
제1절 분리막 생물반응기 (membrane bioreactor, MBR) 17
1.1. MBR 공정의 원리 및 연구개발 동향 17
1.2. MBR의 운영조건과 처리 성능 18
1.3. MBR의 장점 및 단점 19
제2절 MBR 공정에서의 막오염 (fouling in MBR) 20
2.1. 막오염 종류 20
2.2. 생물막오염 21
제3절 막오염 제어 23
3.1. 목적 및 중요성 23
3.2. 역세척 방법 23
3.3. 강화역세척 방법 24
3.4. 화학적 세척방법 26
3.5. 생물학적 제어방법 29
3.6. 기타 막오염 제어방법 29
제4절 정족수 감지 (Quorum sensing) 30
4.1. 그람 음성균의 QS 30
4.2. QS에 의한 생물막 형성 31
4.3. Quorum sensing inhibition (QSI) 32
4.4. 바닐린의 QSI에 대한 연구자의 사례 34
제3장 연구재료 및 방법 35
제1절 연구재료 35
1.1. 화학약품 35
1.2. 실험원수 36
1.3. 분리막 37
1.4. 활성슬러지 38
제2절 연구방법 39
2.1. 실험운전 39
2.2. 역세척 방법 42
2.3. 수질성상분석 방법 43
2.4. 막표면 분석 방법 43
2.5. EPS 추출 및 분석 방법 44
2.6. Fluorescence excitation-emission matrix (F-EEM) 분석 방법 45
제4장 연구결과 및 고찰 47
제1절 바닐린을 이용한 기초실험 결과 47
1.1. 2차 하수처리수에 바닐린을 적용한 membrane filtration simulation 운전 결과 47
제2절 바닐린을 적용한 NaOCl 역세척 농도설정 실험 결과 50
2.1. MBR 운전 결과 50
2.2. NaOCl 역세척 후 막표면에 형성된 biofilm의 EPS 분석 결과 54
2.3. NaOCl 역세척 후 추출된 EPS의 F-EEM 분석 결과 56
제3절 세정방법에 따른 역세척 비교 실험 결과 65
3.1. MBR 운전 결과 65
3.2. 5회 역세척 후 막표면에 형성된 생물막의 EPS 분석 결과 70
3.3. 5회 역세척 후 추출된 EPS의 F-EEM 분석 결과 74
3.4. ATR-FTIR 분석 결과 77
3.5. CLSM 분석 결과 78
제5장 결론 81
1. 바닐린을 이용한 MFS 시스템 운전 결과 81
2. 바닐린을 적용한 NaOCl 역세척 농도설정 실험 결과 81
3. 세정방법에 따른 역세척 비교 실험 결과 82
참고문헌 84
국문초록 91
Table 2.1. Summary of O&M protocols and fouling trends in full-scale installations. 25
Table 2.2. Cleaning agents in membrane process. 27
Table 3.1. Concentration of vanillin and glucose injected into the secondary treated wastewater. (n=3) 36
Table 3.2. Concentration of vanillin and glucose injected into the secondary treated wastewater. 36
Table 3.3. Composition of the synthetic wastewater for lab-scale MBR system. 37
Table 3.4. Specification of ZeeWee 500 hollow fiber membrane. 38
Table 3.5. Specific wavelength range of organic matter in F-EEM. 46
Table 4.1. Biofilm properites from COMSTAT analyses: effects of vanillin on MFS. 49
Table 4.2. EPS cleaning rate compared by fouled and cleaned. PN: protein, PS: polysaccharide, CB: carbohydrate. 56
Table 4.3. Recovery of operation time in MBR process by 5 cycle of backwash. 70
Table 4.4. Biofilm properites from COMSTAT analyses: effects of backwash on MBR membrane. (a) DI water, (b) vanillin, (c) NaOCl, (d) vanillin & NaOCl 80
Fig 2.1. Schematic illustration of colloidal, organic, inorganic, and biofouling. 20
Fig 2.2. Stages of biofilm formation. 22
Fig 2.3. MBR backwasing process. 28
Fig 2.4. The mechanisms of QS in AHL. 31
Fig 2.5. The mechanisms of QS inhibiting agents in AHL. 32
Fig 2.6. AHL-deactivating enzymes. 33
Fig 3.1. Molecular structure of vanillin. 35
Fig 3.2. Shematic diagram of wastewater treatment plant at Guri-si 39
Fig 3.3. Schemetic of MFS system. 40
Fig 3.4. Membrane module for NaOCl concentration setting. 41
Fig 3.5. Schemetic of MBR system. 42
Fig 4.1. CLSM images of biofilm on microfiltration membrane. (a) 0mg/L vanillin, (b) 62.5mg/L vanillin, (c) 125mg/L vanillin, (d) 250mg/L 48
Fig 4.2. Amount of EPS in biofilm. 49
Fig 4.3. The variation of (a) MLSS and (b) MLVSS concentration during the MBR operation. 51
Fig 4.4. The variation of (a) pH and (b) MLVSS/MLSS rate during the MBR operation. 51
Fig 4.5. The rejection rate of MBR permeate during MBR operation. (a) COD, (b) TN, (c) TP 52
Fig 4.6. Variation of TMP of the MBR reactors during the operation. 53
Fig 4.7. Normalized cleaning rate results in EPS analysis. 55
Fig 4.8. Normalized cleaning rate of EPS according to cleaning by concentration of NaOCl. 55
Fig 4.9. Fluorescence intensity results of comparison between fouled and cleaned in the soluble EPS 3D-EEM contour. 58
Fig 4.10. 3D-EEM contour image of soluble EPS. (a) fouled 0mg/L, (b) cleaned 0mg/L, (c) fouled 15mg/L, (d) cleaned 15mg/L,... 58
Fig 4.11. Fluorescence intensity results of comparison between fouled and cleaned in the soluble EPS 3D-EEM contour. 59
Fig 4.12. 3D-EEM contour image of soluble EPS. (g) fouled 62.5mg/L, (h) cleaned 62.5mg/L, (i) fouled 125mg/L, (j) cleaned... 59
Fig 4.13. Fluorescence intensity results of comparison between fouled and cleaned in the soluble EPS 3D-EEM contour. 60
Fig 4.14. 3D-EEM contour image of soluble EPS. (m) fouled 375mg/L, (n) cleaned 375mg/L, (o) fouled 500mg/L, (p) cleaned 500mg/L 60
Fig 4.15. Fluorescence intensity results of comparison between fouled and cleaned in the bound EPS 3D-EEM contour. 62
Fig 4.16. 3D-EEM contour image of bound EPS. (a) fouled 0mg/L, (b) cleaned 0mg/L, (c) fouled 15mg/L, (d) cleaned... 62
Fig 4.17. Fluorescence intensity results of comparison between fouled and cleaned in the bound EPS 3D-EEM contour. 63
Fig 4.18. 3D-EEM contour image of bound EPS. (g) fouled 62.5mg/L, (h) cleaned 62.5mg/L, (i) fouled 125mg/L, (j) cleaned... 63
Fig 4.19. Fluorescence intensity results of comparison between fouled and cleaned in the bound EPS 3D-EEM contour. 64
Fig 4.20. 3D-EEM contour image of bound EPS. (m) fouled 375mg/L, (n) cleaned 375mg/L, (o) fouled 500mg/L, (p) cleaned 500mg/L 64
Fig 4.21. The variation of (a) MLSS and (b) MLVSS concentration during the MBR operation. 66
Fig 4.22. The variation of (a) pH and (b) MLVSS/MLSS rate during the MBR operation. 66
Fig 4.23. The rejection rate of MBR permeate during MBR operation. (a) COD, (b) TN, (c) TP 67
Fig 4.24. Variation of TMP during MBR operation in 5 cycles of backwash. 69
Fig 4.25. Amount of EPS of biofilm after 5 cycles of backwash. 73
Fig 4.26. Amount of soluble EPS and bound EPS of biofilm after 5 cycles of backwash. 73
Fig 4.27. Extent of soluble EPS and bound EPS in total EPS. 74
Fig 4.28. Fluorescence intensity for soluble EPS solution after 5 cycles backwash in 3D-EEM contour. 75
Fig 4.29. 3D-EEM contour image of soluble EPS after 5 cycles backwash. (a) DI water (b) vanillin 125mg/L, (c) NaOCl 250mg/L, (d) vanillin 125mg/L... 75
Fig 4.30. Fluorescence intensity for bound EPS solution after 5 cycles backwash in 3D-EEM contour. 76
Fig 4.31. 3D-EEM contour image of bound EPS after 5 cycles backwash. (a) DI water (b) vanillin 125mg/L, (c) NaOCl 250mg/L, (d) vanillin 125mg/L... 76
Fig 4.32. ATR-FTIR spectra of biofilm on hollow fiber membrane. 78
Fig 4.33. CLSM images of biofilms formed on the hollow fiber membrane. (a) DI water, (b) vanillin, (c) NaOCl, (d) vanillin & NaOCl 80