Modified MLE 공법에서 FISH 및 미소전극 시스템을 이용한 호기성 생물막의 미생물 군집 해석 = Microbial Community Analysis of Aerobic Biofilms in Modified MLE Process by FISH and Microelectrode System

다국어 초록 (Multilingual Abstract)

The characteristics of nitrifying bacteria in the modified MLE process which was put in the media were investigated to evaluate the relationship between nitrification performance and microbial community at the different HRTs. Fluorescence in situ hybridization(FISH) and the ion-selective microelectrode (ISME) system have been adopted to analyze microbial communities and ion concentration profiles according to the acrobic biofilm depth.
Fiber media packed MLE like reactor composed of anoxic, aerobic 1 and 2 was operated with synthetic wastewater having COD 200 mg/L and NH₄^(+)-N 40mg/L at HRT 6h, 4h and 2h.
SCOD_(Cr) removal efficiency was about 90% at all condition. And NH₄^(+)-N removal efficiencies were 61%, 89%, and 35% at HRT 6h, 4h and 2h, respectively. At HRT 6h condition, NH₄^(+)-N showed low efficiency. This was because the loading has to increase for restraining the Nias genuses organism attached media. Therefore, it is necessary to increase the recycle rate to escape the break-through event.
Total biofilm thickness of aerobic 1 and 2 reactor had been thickened as HRT was decreased(aerobic 1 : 6h 380 ㎛, 4h 830 ㎛, 2h 1170 ㎛ ; aerobic 2 : 6h 400 ㎛, 4h 1035 ㎛, 2h 1550 ㎛). HRT 6h condition showed that as deepen the biofilm thickness, NH₄^(+)-N concentration was reduced and removed NH₄^(+)-N was completely oxidized to NO3-N. Though NH₄^(+)-N contration was almost linearly decreased through the biofilm, significant nitrification was not observed at HRT 4h and 2h due to the insufficient HRT.
FISH analysis using EUB338 and Nso190 probe showed that the AOB ratio increased and Nitrospira genus and Nitobacter spp. decreased as the HRT was decreased from 6h and 4h. Under deepen biofilm, the distribution rate of ammonia-oxidizing bacteria(AOB) gradually decreased. From the results of ISME and FISH analysis, it is estimated that most of NH₄^(+)-N decrease at HRT 4h and 2h was occurred by cell synthesis.
It is considered that FISH and ISME can be and appropriate method to investigate the change of the microbial community.

목차 (Table of Contents)

• Ⅰ. 서론 = 1
• Ⅱ. 문헌고찰 = 3
• 2.1 생물막(Biofilm) = 3
• 2.1.1 생물막의 정의 = 3
• 2.1.2 생물막의 형성 및 기질제거 = 3
• 2.1.3 생물막 두께에 영향을 미치는 인자 = 6
• 2.1.4 생물막의 종류와 지표 미생물 = 7
• 2.2 생물학적 질소 제거 = 10
• 2.2.1 질소 동화 = 12
• 2.2.2 생물학적 질산화 = 13
• 2.2.3 질산화 미생물 = 15
• 2.3 Fluorescent In Situ Hybridization(FISH) = 19
• 2.3.1 FISH 개요 = 19
• 2.3.2 FISH 원리 = 20
• 2.4 Ion-Selective Microelectrode(ISME) = 22
• 2.4.1 ISME 개요 = 22
• 2.4.2 ISME 원리 = 22
• 2.4.3 ISME 시스템의 구성 = 24
• Ⅲ. 실험 방법 및 방법 = 27
• 3.1 실험 장치 = 27
• 3.1.1 Modified MLE 공정 = 27
• 3.1.2 합성하수 성상 및 운전조건 = 28
• 3.2 시료 채취 및 분석 항목 = 30
• 3.3 미소전극 = 31
• 3.3.1 생물막의 두께 측정 = 31
• 3.3.2 생물막내 이온 농도 측정 = 31
• 3.4 FISH = 33
• 3.4.1 생물막 샘플 고정 및 미세 절단 = 33
• 3.4.2 Hybridization 방법 = 33
• Ⅳ. 결과 및 고찰 = 36
• 4.1 반응기의 운전 결과 = 36
• 4.1.1 유기물 제거 = 36
• 4.1.2 NH₄^(+)-N 제거 = 38
• 4.2 미소전극 분석 결과 = 401
• 4.2.1 생물막의 두께 측정 = 40
• 4.2.2 생물막내 이온농도 분포 변화 = 42
• 4.3 FISH를 이용한 생물막내 질산화균의 공간 분포 = 46
• Ⅴ. 결론 = 51
• Ⅵ. 참고 문헌 = 53