표제지
국문 초록
목차
1. 서론 17
1.1. 연구 배경 및 목적 17
1.2. 연구내용 및 구성 18
2. 이론적 배경 20
2.1. 전자폐수 증가 추세 20
2.2. 전자 폐수의 일반적 특성 21
2.3. 반도체 제조 공정 23
2.3.1. 식각폐수의 발생 25
2.4. 불소의 독성 27
2.4.1. 불소(Fluorine) 27
2.4.2. 생체에 미치는 영향 28
2.4.3. 불화수소(HF, hydrogen fluoride) 29
2.5. 응집·침전 이론 30
2.5.1. 응집의 정의 30
2.5.2. 입자의 안정화 특성 31
2.5.3. 입자의 불안정화 원리 35
2.5.4. 응집제를 이용한 응집 40
2.5.5. 응집의 영향 인자 42
2.6. 불산 폐수처리 44
2.6.1. 불소 제거 방법 44
2.6.2. 전자제품 산업 불산폐수 처리 51
2.7. 응집제의 종류 52
2.7.1. 소석회(Calcium hydroxide) 52
2.7.2. PACl(Poly-aluminum chloride) 54
2.8. 법적 규제 변화 55
3. 연구 방법 58
3.1. 실험방법 및 분석방법 58
3.1.1. 처리 대상 불산 폐수 시료 61
3.1.2. 약품 선정 61
3.1.3. Jar-test 64
3.1.4. 분석 방법 64
3.2. 기존 불산폐수 불소제거 공정 65
3.2.1. 1차 처리 66
3.2.2. 2차 처리 66
3.3. 별도 pH 조정제 투입을 통한 개선 공정 실험 67
3.3.1. 1차 처리 68
3.3.2. 2차 처리 68
4. 실험결과 및 고찰 70
4.1. 기존 불산폐수 불소제거 공정 70
4.1.1. 1차 처리 - 1단계(소석회) 70
4.1.2. 1차 처리 - 2단계(PACl) 73
4.1.3. 2차 처리(PACl→소석회) 75
4.2. 별도 pH조정제 투입을 통한 공정개선 방안 80
4.2.1. 1차 처리(소석회+pH조정제) 80
4.2.2. 2차 처리(PACl+pH조정제) 83
5. 결론 96
References 99
ABSTRACT 107
Table 2.1. General Characteristics of Semiconductor Wastewater Quality 22
Table 2.2. Physical and Chemical Properties of Hydrogen Fluoride 30
Table 2.3. Surface characteristics of particulates commonly found in natural waters 38
Table 2.4. Permissible Emission Standards for Water Pollutants - Fluoride 55
Table 2.5. Integrated Management Target Industries and Application Period 57
Table 3.1. Comparison of Existing and Improved process 60
Table 3.2. Hydrofluoric acid wastewater quality 61
Table 3.3. Types of Coagulants and Coagulant Aids 62
Table 3.4. Chemicals used in the experiment 63
Table 4.1. Concentration of F and T-P over Ca(OH)₂ Concentration in Existing treatment process 72
Table 4.2. Concentration of F and T-P over PACl Concentration in 1st Treatment[이미지참조] 74
Table 4.3. Concentration of F and T-P over PACl Concentration in 2nd Treatment[이미지참조] 76
Table 4.4. Concentration of Chloride & SVI over PACl Concentration in Existing process 78
Table 4.5. Concentration of F and T-P over Ca(OH)₂ Concentration in Improved treatment process - 1st Treatment[이미지참조] 82
Table 4.6. Concentration of F and T-P over PACl Concentration in Improved treatment process(2nd Treatment, pH 11.01)[이미지참조] 84
Table 4.7. Concentration of F and T-P over PACl Concentration in Improved treatment process(2nd Treatment, pH 10.45) 85
Table 4.8. Concentration of F and T-P over PACl Concentration in Improved treatment process(2nd Treatment, pH 10.04)[이미지참조] 86
Table 4.9. Concentration of F and T-P over PACl Concentration in Improved treatment process(2nd Treatment, pH 9.55)[이미지참조] 88
Table 4.10. Concentration of Chloride & SVI over PACl Concentration in Improved process 90
Table 4.11. Comparison of Chemical consumption & SVI for Existing and Improved process 94
Figure 2.1. Wastewater Generation and Discharge Status by Industry Classification 20
Figure 2.2. Wastewater Discharge and Treatment Flow in the Semiconductor Wafer Processing Procedure 24
Figure 2.3. (a) Stable particles and (b) Unstable particles 31
Figure 2.4. Schematic of electrical double layer at solid-liquid interface 33
Figure 2.5. Schematic of double layer (a) Effect of increasing concentration of indifferent electrolyte, (b) Reversal of... 34
Figure 2.6. Equilibrium composition of solutions in contact with freshly precipitated Al(OH)₃ and Fe(OH)₃ 42
Figure 2.7. Relationship between pH and the distribution of soluble aluminum species 47
Figure 2.8. Hydrofluoric acid wastewater treatment(Best Available Techniques Reference Document) 51
Figure 3.1. Existing hydrofluoric acid wastewater treatment process 58
Figure 3.2. Improved hydrofluoric acid wastewater treatment process 59
Figure 3.3. Existing hydrofluoric acid wastewater treatment process - 1st Treatment[이미지참조] 66
Figure 3.4. Existing hydrofluoric acid wastewater treatment process - 2nd Treatment[이미지참조] 67
Figure 3.5. Improved hydrofluoric acid wastewater treatment process - 1st Treatment[이미지참조] 68
Figure 3.6. Improved hydrofluoric acid wastewater treatment process - 2nd Treatment[이미지참조] 69
Figure 4.1. Correlation between Ca(OH)₂ concentration and pH 71
Figure 4.2. Concentration of F and T-P over Ca(OH)₂ Concentration with New Optimal pH Range for F Removal 72
Figure 4.3. Correlation between PACl concentration and pH 74
Figure 4.4. Concentration of F and T-P over PACl Concentration in 1st Treatment[이미지참조] 75
Figure 4.5. Variation in Ca(OH)₂ Concentration with PACl Injection Concentration under Neutral pH Conditions 77
Figure 4.6. Concentration of F and T-P over PACl Concentration in 2nd Treatment[이미지참조] 78
Figure 4.7. Concentration of Chloride over PACl Concentration in Existing process 79
Figure 4.8. SVI over PACl Concentration in Existing process 80
Figure 4.9. Concentration of F and T-P over pH in Advanced treatment process 83
Figure 4.10. Concentration of F and T-P over PACl in Advanced treatment process(pH 11.1) 85
Figure 4.11. Concentration of F and T-P over PACl in Advanced treatment process(pH 10.45) 86
Figure 4.12. Concentration of F and T-P over PACl in Advanced treatment process(pH 10.04) 87
Figure 4.13. Concentration of F and TP over PACl in Advanced treatment process(pH 9.55) 89
Figure 4.14. Concentration of Chloride over PACl Concentration in Improved process 91
Figure 4.15. SVI over PACl Concentration in Improved process 92
Figure 4.16. Concentration of Sulfate over PACl Concentration in Improved process 93