표제지

목차

제1장 서론 11

제2장 문헌연구 14

2.1. 수질기준과 인체유해성 14

2.2. 분석법 16

2.3. 국내외 관련 연구동향 18

2.4. 니트로사민류 생성메카니즘 20

제3장 실험재료 및 방법 24

3.1. 니트로사민류 분석(SPE-GC/LRMS) 24

3.1.1. 실험재료 24

3.1.2. 전처리방법 27

3.1.3. 분석조건 27

3.1.4. 검량선 작성 30

3.1.5. 검출한계(LOD) 및 정량한계(LOQ) 30

3.1.6. 분석방법의 신뢰도 검증 33

3.2. 하천수에서의 니트로사민류 모니터링 36

3.2.1. 채수지점 및 채수시기 36

3.2.2. 채수방법 36

3.3. 상하수도에서의 니트로사민류 모니터링 38

3.3.1. 채수지점 및 채수시기 38

3.3.2. 채수방법 38

3.4. 오존 및 오존/과산화수소(AOP) 공정에서의 니트로사민류 산화 특성 실험 39

3.4.1. 대상시료 39

3.4.2. 실험재료 및 실험장치 40

3.4.3. 실험방법 42

3.5. 입상활성탄 공정에서의 니트로사민류 흡착 특성 실험 42

3.5.1. 대상시료 42

3.5.2. 실험재료 43

3.5.3. 실험방법 44

3.6. 기타 수질항목 분석방법 45

제4장 결과 및 고찰 46

4.1. 하천수에서의 니트로사민류 모니터링 46

4.1.1. 연구목적 46

4.1.2. 낙동강에서의 니트로사민류 모니터링 결과 47

4.1.3. 니트로사민류 형성과 총질소와의 상관관계 57

4.2. 상하수도에서의 니트로사민류 모니터링 58

4.2.1. 연구목적 58

4.2.2. 하수처리장 방류수에서의 니트로사민류 모니터링 59

4.2.3. 정수공정별 니트로사민류 거동 조사 65

4.3. 오존 및 오존/과산화수소(AOP) 공정에서의 니트로사민류 산화 특성 68

4.3.1. 연구목적 68

4.3.2. 원수에서의 니트로사민류 산화 특성 70

4.3.3. 급속 모래여과수에서의 니트로사민류 산화 특성 78

4.4. 입상활성탄 공정에서의 니트로사민류 흡착 특성 84

4.4.1. 연구목적 84

4.4.2. 니트로사민류의 파과 특성 85

4.4.3. 니트로사민류의 흡착능 평가 88

제5장 결론 94

참고문헌 98

Abstract 112

Table 3.1 Physical and chemical properties of nine nitrosamine compounds used in this study 25

Table 3.2 Analytical conditions of GC/LRMS 29

Table 3.3 Analytical parameters of the nitrosamines analyzed by GC/LRMS 32

Table 3.4 Accuracy and precision of a proposed method 35

Table 3.5 Characteristics of column oxidation test influent water 39

Table 3.6 Characteristics of continuous column adsorption test influent water 43

Table 3.7 Characteristics of coal-based virgin GAC(Granular Activated Carbon) 43

Table 3.8 Analytical item and instruments 45

Table 4.1 Nitrosamine monitoring results at Nakdong river in April and August, 2009 55

Table 4.2 Flow rates at the sampling sites 56

Table 4.3 Characteristics of the studied STPS 60

Table 4.4 Characteristics of samples in the studied STPs 61

Table 4.5 Resulting data of nitrosamines in the studied STPs 64

Table 4.6 BVbreakthrough and bed life of coal-based virgin GAC for nine nitrosamines(이미지참조) 87

Table 4.7 Adsorption capacity data of coal-based virgin GAC for seven nitrosamines 92

Fig. 2.1. Proposed reaction scheme for NDMA formation from DMA and monochloramine 23

Fig. 2.2. Formation mechanism of NDMA by free chlorine and nitrite 23

Fig. 3.1. Molecular structures of NDMA and other nitrosamines 26

Fig. 3.2. Sampling sites along the Nakdong river (blue square indicates a sampling site at a main river and red circle a site at branch stream) 37

Fig. 3.3. Schematic diagram of O₃/H₂O₂contactor 41

Fig. 3.4. Schematic diagram of continuous adsorption column system 44

Fig. 4.1. Sewage treatment plant locations in the K area 49

Fig. 4.2. TIC(Total ion chromatogram) : (a) STD 500 ng/L, (b) shinchun (S8, April), (c) Goryung (S11, August) 50

Fig. 4.3. Total nitrosamine concentration along the sampling sites from S10 to S15 56

Fig. 4.4. Correlation between total nitrosamines concentration and T-N concentration 57

Fig. 4.5. Variations of NMEA and NDEA concentration in A and B drinking water treatment plant 67

Fig. 4.6. Removal results of nitrosamines by O₃(2.0 mg/L) alone with various contact time at concentration of nitrosamines of 20 ㎍/L in raw water 73

Fig. 4.7. Removal results of nitrosamines by O₃(5.0 mg/L) alone with various contact time at concentration of nitrosamines of 20 ㎍/L in raw water 74

Fig. 4.8. Removal results of nitrosamines by O₃(10.0 mg/L) alone with various contact time at concentration of nitrosamines of 20 ㎍/L in raw water 75

Fig. 4.9. Comparison of removal results of nitrosamines under various O₃concentration with contact time of 20 minutes at concentration of nitrosamines of 20 ㎍/L in raw water 76

Fig. 4.10. Comparison of removal results of nitrosamines under various contact time by O₃/H₂O₂(10.0 mg/L / 5.0 mg/L) and O₃(10.0 mg/L) at concentration of nitrosamines of 20 ㎍/L in raw water 77

Fig. 4.11. Removal results of nitrosamines by O₃(2.0 mg/L) alone with various contact time at concentration of nitrosamines of 20 ㎍/L in rapid sand filtered water 80

Fig. 4.12. Removal results of nitrosamines by O₃(5.0 mg/L) alone with various contact time at concentration of nitrosamines of 20 ㎍/L in rapid sand filtered water 81

Fig. 4.13. Removal results of nitrosamines by O₃(10.0 mg/L) alone with various contact time at concentration of nitrosamines of 20 ㎍/L in rapid sand filtered water 82

Fig. 4.14. Comparison of removal results of nitrosamines under various contact time by O₃/H₂O₂(10.0 mg/L / 5.0 mg/L) and O₃(10.0 mg/L) at concentration of nitrosamines of 20 ㎍/L in rapid sand filtered water 83

Fig. 4.15. Breakthrough curves of coal-based virgin GAC for nine nitrosamines 87

Fig. 4.16. Adsorption isotherm for seven nitrosamines of coal-based virgin GAC 93

Fig. 4.17. Evaluation of correlations between X/M and Kow(이미지참조) 93

 The survey of nitrosamines occurrence at Nakdong river is conducted in this study. The nine nitrosamines were analyzed by GC/LRMS using solid phase extraction (SPE) with a coconut charcoal cartridge. According to the study results, six nitrosamine compounds (NDMA, NMEA, NDEA, NDPA, NDBA, and NDPHA) were detected as ND~33.8 ng/L, ND~17.7 ng/L, ND~151.6 ng/L, ND~455.4 ng/L, ND~330.1 ng/L and ND~161.0 ng/L respectively at the Nakdong river. Among these, NDEA and NDPA are the most important compounds in terms of the nitrosamine contamination of the Nakdong river. The detected concentration of NDEA exceeded the CDHCS (California Department of Health Care Services) response level of 100 ng/L at several sites. The detected concentration of NDPA approached the response level (500 ng/L) at a few sites. When all nitrosamine concentrations were summed up, the maximum concentration of 735.7 ng/L was detected at the Nakdong river. An equation describing a decrease in total nitrosamine concentration along downstream sampling sites was proposed in this study. The equation can be used to predict the downstream nitrosamine contamination at the Nakdong river. Among various water quality parameters, T-N showed a good correlation with total nitrosamine concentration.

Also this study was detected five nitrosamines(NDMA, NMEA, NDEA, NDPA and NDBA) in Sewage Treatment Plants(STPs). NDMA, NMEA, NDEA, NDPA and NDBA were obtained ND~821.4 ng/L, 22.5~55.4 ng/L, 53.2~588.5 ng/L, ND~56.6 ng/L and ND~527.9 ng/L in STPs, respectively. At the Dalseocheon STP, NDMA was obtained as 821.4 ng/L. In Drinking Water Treatment Plants(DWTP), NMEA and NDEA concentration were increased to as high as 38.8 ng/L after ozonation process. However nitrosamines were decreased subsequent biological activated carbon(BAC) treatment process. It was supposed that nitrosamines were formed by O₃ oxidation and were removed by biodegradation of BAC.

Oxidation characteristics by O₃ alone and advanced oxidation process(AOP) O₃/H₂O₂ were investigated with concentration of nine nitrosamines of 20 ㎍/L in the raw water and the rapid sand filtered water. In the raw water, the results showed that the average removal efficiencies were maximum 43% by O₃(5.0 mg/L) alone with contact time of 2 minute for NDMA, NMEA and NDEA and maximum 48% by O₃(10.0 mg/L) alone with contact time of 20 minute for NPYR, NDPA, NMOR, NPIP, NDBA and NDPHA. In the rapid sand filtered water, the results showed that the av-erage removal efficiencies were about 50% by O₃(5.0 mg/L) alone with contact time of 2 minute for nine nitrosamines. The average removal efficiencies by AOP process were increased more than 30% by O₃(10.0 mg/L)/H₂O₂(5.0 mg/L) with contact time of 2~20 minute than O₃(10.0 mg/L) alone with contact time of 2 minute in the raw water and the rapid sand filtered water. On the other hand, Concentrations of nitrosamines after oxidation process were higher than initial concentration of nitrosamines when O₃ doses of 0.5~1.0 mg/L were applied. Thefore O₃ doses for removal of nine nitrosamines were needed higher than O₃ doses of 0.5~1.0 mg/L.

Besides, this study accessed the adsorption characteristics of the nine nitrosamine species on coal-based granular activated ca-rbon (GAC). The breakthrough appeared first for NDMA and sequentially for NMOR, NPYR, NMEA, NDPA, NDEA, and NPIP. On the other hand, NDBA and NDPHA were not detected in the treated effluent for the operation period. The maximum ads-orption capacity (X/M) for the seven nitrosamine species with apparent breakthrough points ranged from 52.8 ㎍/g (for NDMA) to 5027.2 ㎍/g (for NPIP). Carbon usage rate (CUR) for NDMA was 1.07 g/day, 13.4 times higher than that for NPIP (0.08 g/day). The X/M values for the seven nitrosamine species were fitted well with a linear regression (r²=0.94) by their octanol-water par-titioning coefficient (Kow).

Finally, the results of this study are expected to be useful for water quality management in DWTP.