천연고분자물질인 CHITOSAN과 PAC의 응집특성 비교에 관한 연구 = A Study on the Comparison of Coagulation Characteristics between CHITOSAN(Natural Polymer Coagulant) and PAC

다국어 초록 (Multilingual Abstract)

Coagulant, such as Alum and PAC, is being used for purification processing in domestic water treatment plants. Since the aluminum that is included in aluminum coagulant is a metalloid, it has great chance of remaining during the filtration process combining with organic matters within water from water supply source. Also, as the quantity of aluminum combined with organic matter increases, the quantity of aluminum needed for condensation decreases, which causes problems that need a great quantity of aluminum inputted at cohesion. Above all, the treat ability drops due to the sludge produced when processing water from water supply source that contains a great amount of organic matters.
Due to these problems, Germany and the Netherlands uses steel flocculants, instead of aluminum flocculants, in eutrophicationized dam and lakes for water supply sources.
Chitosan, which is a natural polymer matter, is acquired from Chitin that is obtained by chemical processing on crab's shell. This matter shows to be positively ionized as a water solution and also shows superiority in biodegradable ability, stability and dehydrate ability, which makes it a prospect for natural polymer coagulant.
This research was done to figure the condensing characteristics, such as, removal rate of turbidity matters and DOC generation, which is a THM precursor, through a jar test comparing Chitosan, a natural polymer coagulant, and PAC, a Alum coagulant.
Chitosan with a greater degree of alkali has been required, which concludes that pH affects the optimized condensation of Chitosan. As the input of Chitosan increases the remaining turbidity decreased, where the optimized input quantity turned out to be 40mg/l.
Chitosan also showed equal efficiency with PAC, where sedimentation time and removal efficiency was not in concern. As the input of Chitosan increased the density of the remaining DOC also increased. This result was shown because Chitosan requires a high level of alkali. Also, 8 minutes was mentioned for an appropriate precipitation time taking the DOC generation quantity into account.

목차 (Table of Contents)

• 1. 서론 = 1
• 1.1 연구배경 및 목적 = 1
• 1.2 연구방법 및 범위 = 3
• 2. 이론적배경 = 5
• 2.1 응집 침전 = 5
• 2.1.1 콜로이드의 분산 = 5
• 2.1.2 콜로이드의 안정성 = 5
• 2.1.3 입자의 성질 및 표면전하 = 9
• 2.1.4 입자의 응집(Particle Aggregation) = 10
• 2.1.5 응집원리 = 12
• 2.2 최적응집을 위한 물리화학적 조건 = 14
• 2.2.1 속도경사와 응집과의 관계 = 14
• 2.2.2 급속교반의 강도와 교반시간 = 16
• 2.3 응집제의 종류와 특성 = 16
• 2.3.1 무기응집제 (Inorganic Coagulant) = 16
• 2.4 응집의 물리화학적 영향인자 = 21
• 2.4.1 수온 = 21
• 2.4.2 pH와 알카리도 = 21
• 2.4.3 탁도의 영향 = 23
• 2.4.4 응집제의 균일한 분포 = 24
• 2.4.5 공존물의 영향 = 25
• 2.5 키토산 (Chitosan) = 25
• 2.5.1 키토산의 특징 = 26
• 2.5.2 키틴/키토산의 성분 및 구조 = 26
• 3. 실험 재료 및 방법 = 29
• 3.1 실험 재료 = 29
• 3.2 실험 방법 = 31
• 3.2.1 Jar test = 31
• 3.2.2 DOC(Dissolved Organic Carbon) = 32
• 4. 결과 및 고찰 = 33
• 4.1 Chitosan 과 PAC의 최적응집조건 = 33
• 4.1.1 알카리도에 따른 탁도제거 = 33
• 4.1.2 응집제주입량에 따른 탁도제거 = 36
• 4.1.3 침전시간에 따른 탁도제거 = 39
• 4.1.4 농도변화에 따른 탁도제거 = 40
• 4.1.5 응집제의 기여도 = 40
• 4.2 응집제별 잔류DOC = 43
• 4.2.1 PAC와 Chitosan의 주입량에 따른 잔류 DOC = 43
• 4.2.2 PAC와 Chitosan의 침전시간 변화에 따른 잔류 DOC = 45
• 4.2.3 최적조건에서 low, medium, high turbidity에 따른 DOC농도 = 48
• 5. 결론 = 49
• 참고문헌 = 51