표제지

눈문요약본

목차 17

I. 서론 26

1.1 연구배경 26

1.2 슬러지 침전분리문제 28

1.2.1 2 차 침전지의 기능 28

(1) 고형물의 이동 28

(2) 2차 침전지에서 고형물 수지 30

(3) 침전지의 기능과 역할 31

1.2.2 벌킹 33

1.2.3 거품 35

1.2.4 기타 침전분리문제 36

1.3 목적 38

1.4 연구내용 38

II. 연구방법 39

2.1 연구대상 하수처리장 39

2.2 슬러지 침전성 분석 41

2.3 슬러지 블랑킷 깊이의 측정 41

2.4 수질분석 42

2.5 원인 미생물의 동정 43

2.6 사상균의 길이 및 플럭형성 분석 43

III. 연구결과 및 고찰 44

3.1 연구대상 하수처리장 침전문제의 진단 44

3.1.1 진단결과 44

(1) 벌킹 44

(2) 포기조 및 2차 침전지 거품문제 45

3.1.2 사상체의 판정결과 47

3.2 Microthrix 벌킹/거품문제의 해결 56

3.2.1 사상체의 증식요인 56

3.2.2 탈수기 확충을 통한 SRT의 감축 60

3.2.3 Microthrix parvicella의 발생추이 61

3.2.4 Filament의 길이 변화 64

3.2.5 SV30/SVI의 변화 64

3.2.6 슬러지 블랑킷 깊이 66

3.2.7 거품발생추이 68

3.3 염소처리실험 71

3.3.1 염소처리 71

3.3.2 염소처리 실험결과 73

3.4 2차 침전지에서 플럭의 형상 80

3.4.1 플럭 size 분포 80

3.4.2 Filament length 84

3.4.3 플럭의 형태 85

3.4.4 기술제안 87

3.5 Microthrix가 처리성능에 미치는 영향 89

3.5.1 공정수질분석결과 89

3.5.2 유입하수수질 92

3.5.3 영양소제거공정 93

3.5.4 총괄성능 96

IV. 종합평가 및 결론 99

4.1 슬러지 침전문제의 진단 99

4.2 슬러지 벌킹제어 99

4.3 벌킹제어방법 99

4.4 벌킹문제 해결시 예상되는 문제점 100

4.5 2차 침전지에서 벌킹 슬러지의 침전양상 100

참고문헌 101

ABSTRACT 107

부록 109

부록.1 Process water quality data 109

부록.2 Microphotograph collection 119

Table.1. Causes of sludge bulking and filaments 34

Table.2. Dimension of the treatment processes 40

Table.3. Evaluation of the sludge settling characteristics 44

Table.4. Total filament length 47

Table.5. Identification results of the causative filamentous microorganism 51

Table.6. SS concentration recycled from sludge treatment facilities to the head of processes 61

Table.7. Summarized results of sludge chlorination 77

Table.8. Chlorination parameters suggested in literatures 78

Table.9. Chlorination parameters for two different options 79

Table.10. Summarized process data 90

Table.11. Overall treatment performance 91

Fig. 1. Diagram of the waste water and sludge flows in BNR processes 29

Fig. 2. Functions of the secondary settling tanks 32

Fig. 3. Types of sludge floc 37

Fig. 4. Municipal wastewater treatment plant: process diagram 39

Fig. 5. Location of sludge blanket sampling 41

Fig. 6. Occurrence of bulking/foaming and monitoring parameter and sampling point 42

Fig. 7. Comparison of the zone settling velocity 45

Fig. 8. Dichotomous key for filamentous microorganism "identification" in activated sludge 52

Fig. 9. Pathway of the M. parvicella in the processes 57

Fig. 10. Decrease of the sludge residence time 60

Fig. 11. TFL changes in MLSS during the period of study 64

Fig. 12. Changes of the SV30 and SVI values during the period of study 65

Fig. 13. Relationship between filament length and SVI 66

Fig. 14. Changes of the average SBD in clarifiers 67

Fig. 15. Changes of the average SBSS concentration 67

Fig. 16. Various chlorination points 71

Fig. 17. Settling curve according to chlorine dosage rate 76

Fig. 18. Cumulative floc size distribution in a longitudinal direction of clarifiers (a: SBD#1, b: SBD#7, c: SBD#12) 81

Fig. 19. Comparison between median floc sizes 82

Fig. 20. Filament length in an unit volume of sludge 84

Fig. 21. Normalized filament length 85

Fig. 22. Conceptual diagram of double hopper settling tanks 88

Fig. 23. Organic matters in raw sewage 92

Fig. 24. Contribution of the recycled flows to the loadings 93

Fig. 25. Changes of the SCOD, nitrogen and phosphorus species 94

Fig. 26. Nitrogen fraction in the final effluent 95

Fig. 27. Pfraction in the final effluent 95

Fig. 28. Changes of the water quality parameters during two different periods 97

Fig. 29. Comparison of the portion-P 98

Photo.1. Measurement of the floc size and filament length 43

Photo.2. Foaming problem in oxic tank 46

Photo.3. Foaming problem in secondary settling tank 46

Photo.4. Microphotographs of MLSS and foam (2 times diluted 100×; a MLSS, b foam) Diffuse floc structures with different sizes and difficult to observe the presence of filament in 100× 48

Photo.5. Microphotographs of MLSS and foam (400×; a, b MLSS, c, d foam). Filaments extending from floc surface of MLSS and foam. More filaments can be observed in foam than in MLSS. Staining reaction: G+ 49

Photo.6. Microphotographs of MLSS and foam (100×; a MLSS, b foam, 400 ×; c MLSS d foam). Compac tfloc is observed in foam where as loose floc is observed in MLSS. foam: excessive filament. MLSS: common. Staining reaction: G+ 50

Photo.7. Gram stain reaction (400×; a MLSS, b, c foam) G+ as well as G-filaments can be observed Neisser stain reaction (1000×; d MLSS, e, f foam) N+ as well as N- filaments can be observed 53

Photo.8. PHB reaction (1000×; a, b MLSS, c, d foam). foam (phase contrast 1000×; e, f) 54

Photo.9. SEM image (a, b, c MLSS, d, e, f foam). No branching. Spagetti-like filament : M. parvicella. Diameter [ 1 ㎛, Length] 400㎛ 55

Photo.10. M. parvicella in recycled stream, (1000×; a, b, c, d) 57

Photo.11. Microphotographs of MLSS and foam (100×) 62

Photo.12. Microphotographs of MLSS and foam (400×) 63

Photo.13. Changes in the amount of foam in secondary settling tank. (Pictures taken from a fixed pointin secondary settling tank) 69

Photo.14. Changes in the amount of foam in secondary settling tank.(Pictures taken from a fixed pointin secondary settling tank) Continue 70

Photo.15. Use of 4% NaOCl for chlorination (100×; a: control, b: 0.2mL, c: 0.5mL, d: 0.8mL, e: 1.0mL, f: 1.2mL). More fragment of filaments are observed as the chlorine dose is increased 74

Photo.16. Use of 4% NaOCl for chlorination (400×; a: control, b: 0.2mL, c: 0.5mL, d: 0.8mL, e: 1.0mL, f: 1.2mL). More fragment of filaments are observed as the chlorine dose is increased 75

Photo.17. Typical shape and size of the flocs in the sludge blanket sludge (a, b: SBD #1, c, d: SBD #7, e, f: SBD #12) 86

Table.1 Process water quality data (2005.4.13) 109

Table.2 Process water quality data(2005.4.20) 110

Table.3 Process water quality data(2005.4. 27) 111

Table.4 Process water quality data(2005.5.4) 112

Table.5 Process water quality data(2005.5.11) 113

Table.6 Process water quality data(2005.5.18) 114

Table.7 Process water quality data(2005.5.25) 115

Table.8 Process water quality data(2005.6.1) 116

Table.9 Process water quality data(2005.6.8) 117

Table.10 Process water quality data(2005.6.15) 118

부록사진목차

Photo.1 Microphotographs of MLSS and foam (100×, MLSS; a, b, c, foam ; d, e, f).2005.4. 20 119

Photo.2 Microphotographs of MLSS and foam (400×, MLSS; a, b, c, foam ; d, e, f).2005.4. 20 120

Photo.3 Microphotographs of MLSS and foam (100×, MLSS; a, b, c, foam ; d, e, f).2005.4. 27 121

Photo.4 Microphotographs of MLSS and foam (400×, MLSS ; a, b, c, foam ;d, e, f).2005.4 .27 122

Photo.5 Microphotographs of MLSS and foam (100×, MLSS ; a, b, c, foam ; d, e, f ).2005.5 .4 123

Photo.6 Microphotographs of MLSS and foam (400×, MLSS ; a, b, c, foam ; d, e, f).2005.5 .4 124

Photo.7 Microphotographs of MLSS and foam (100×, MLSS ;a, b, c, foam ; d, e, f).2005.5 .11 125

Photo.8 Microphotographs of MLSS and foam (400×, MLSS ; a, b, c, foam ; d, e, f).2005.5 .11 126

Photo.9 Microphotographs of MLSS and foam (100×, MLSS ;a, b, c, foam ; d, e, f).2005.5 .18 127

Photo.10 Microphotographs of MLSS and foam (400×, MLSS ; a, b, c, foam ; d, e, f).2005.5 .18 128

Photo.11 Microphotographs of MLSS and foam (100×, MLSS ;a, b, c, foam ;d, e, f).2005.5 .25 129

Photo.12 Microphotographs of MLSS andf oam (400×, MLSS ;a, b, c, foam ;d, e, f).2005.5 .25 130

Photo.13 Microphotographs of MLSS and foam (100×, MLSS ;a, b, c, foam ;d, e, f).2005.6 .1 131

Photo.14 Microphotographs of MLSS and foam (400×, MLSS ;a, b, c, foam ;d, e, f).2005.6 .1 132

Photo.15 Microphotographs of MLSS and foam (100×, MLSS ;a, b, c, foam ;d, e, f).2005.6 .8 133

Photo.16 Microphotographs of MLSS and foam (400×, MLSS ;a, b, c, foam ;d, e, f).2005.6 .8 134

Photo.17 Microphotographs of MLSS and foam (100×, MLSS ;a, b, c, foam ;d, e, f).2005.6 .15 135

Photo.18 Microphotographs of MLSS and foam (400×, MLSS ;a, b, c, foam ;d, e, f).2005.6 .15 136