• Proceedings of the Korean Environmental Sciences Society Conference
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• 2000.05a
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• pp.126-127
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• 2000

Fe(III) 응집제는 pH 5～9범위에서 Al(III)계 응집제보다 보다 우수한 응집효과를 보였으며 또한 pH의 영향을 거의 받지 않는 것으로 나타났다. 잔류 Fe의 경우 응집제 주입농도와 pH 증가에 영향을 거의 받지 않고 저농도의 잔류 Fe농도를 나타낸 반면, Al(III) 응집제는 잔류 Al의 급격한 증가를 나타내었다.

• Journal of Life Science
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• v.27 no.8
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• pp.930-936
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• 2017

The flocculating properties of bioflocculant Biopol32 produced by Pseudomonas sp. GP32 were investigated for application in industrial wastewater treatment. The major flocculating substance of bioflocculant Biopol32 was identified as polysaccharide. Many anionic flocculants need a counter ion to induce higher flocculating activity. The flocculating activity of bioflocculant Biopol32 was markedly increased by the addition of cationic ions ($Ca^{2+}$, $Al^{3+}$). The flocculating activity of bioflocculant Biopol32 was the most effective when 7.0 mM $CaCl_2{\cdot}2H_2O$ as coflocculant was added. The flocculating activity on the effect of pH and the temperature of the bioflocculant Biopol32 was compared with anionic commercial flocculant (polyacrylamide) and bioflocculant (zooglan from Zoogloea ramigera). In kaolin suspension, the highest flocculating activity was obtained at the bioflocculant Biopol32 concentration of 1.5 mg/l. A high flocculating activity was observed in the pH range of 5.0 to 8.0. The flocculating activity of bioflocculant Biopol32 was sustained up to $60^{\circ}C$, but decreased rapidly at over $70^{\circ}C$. In the batch culture, the charge density of bioflocculant Biopol32 was compared with flocculating activity. The larger the anionic charge density and apparent viscosity of bioflocculant Biopol32, the higher the flocculating activity. Therefore, we confirmed that the flocculating activity and apparent viscosity of bioflocculant Biopol32 was closely related to the charge density of bioflocculant Biopol32.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 1999.10a
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• pp.119-120
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• 1999

응집은 입자들간의 상대운동에 의하여 두 입자가 충돌하여 하나의 입자가 되는 것을 말하는데, 상대 운동을 유발하는 원인에 따라 중력응집(gravitational coagulation)을 비롯하여 브라운응집(Brownian coagulation), 난류응집(turbulent coagulation)등으로 나뉜다. 브라운응집 및 난류응집에 비하여 상대적으로 중력응집은 해석적으로 풀기가 어렵고 실험에 대한 연구가 국내외는 물론 외국에서도 전무한 실정이다.(중략)

• Proceedings of the Korea Water Resources Association Conference
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• 2017.05a
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• pp.197-197
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• 2017

본 연구에서는 입자성 오염물질을 다량 함유하고 있는 초기강우 유출수를 처리하기 위한 수처리 시설로 고속복합응집장치를 개발하였다. 고속응집복합장치의 요소기술은 마이크로 버블, 급속교반장치(인라인믹서), 전기촉매를 이용한 부상촉진장치, 볼텍스 흐름 등으로 구성되며, 기술 원리는 응집제에 의해 오염물질을 응결, 응집, 부상시켜 스컴을 제거하는 일반 응집 원리와 유사하다. 본 기술의 특징은 교반, 혼화조, 응집제를 1개의 조에 컴팩트하게 구성하여 체류시간을 10분 이내로 단축하였고, 볼텍스(voltex) 흐름을 이용한 선회류와 루버홀 형태의 스크린을 적용하여 응집효과를 극대화하였으며, 플럭에 의한 막힘이 없이 스크리닝이 이루어질 수 있도록 하였다. 또한, 부상촉진장치(전기유도)를 이용해 응집 플럭의 부상효과를 상승시켰고, 감속기와 일체화된 내통스크린이 선회류와 반대 방향으로 회전하면서 볼텍스 흐름의 가속효과에 의한 스크린 폐색 방지 및 응집부상 효율을 향상시킬 수 있도록 설계하였다. 부상슬러지는 별도의 플럭 제거 설비 없이 스크린 내통 회전에 이용되는 감속기에 부착된 스컴 제거기에 의해 동시 제거가 가능하며, 응집부상 처리수는 장치 가장 바깥 외곽에 충진된 필터층에서 최종 여과되어 방류되도록 구성함으로서 모든 처리공정이 단일 장치 내에서 이루어지도록 구성하였다. 본 고속복합응집장치는 전체 규격 ￠ $1000{\times}2,000mmH$의 시제품이 제작되어 현재 시흥소재 매화저수지에서 성능평가를 실시하고 있다.

• Journal of Korean Society of Environmental Engineers
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• v.37 no.6
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• pp.325-331
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• 2015

The experimental results of the characteristics of aluminum based and ferric based coagulants for the Nakdong River water showed that the main hydrolysis species contained in alum and $FeCl_3$ are monomeric species of 98% and 93.3%, respectively. The PACl of r=1.2 produced by the addition of base contained 31.2% of polymeric Al species and the PACl of r=2.2 contained 85.0% of polymeric Al species, as showing more polymeric Al species with increasing r value. Coagulation tests using Al(III) and Fe(III) salts coagulants for the Nakdong River water showed that the coagulation effectiveness of turbidity and organic matter was high in the order of $FeCl_3$ > PACl (r=2.2) > PACl (r=1.2) > alum. $FeCl_3$ has showed better flocculation efficiency than Al(III) salts coagulants. In addition, in case of Al(III) coagulants, the Al(III) coagulants of higher basicity, which contained more polymeric Al species, resulted in better coagulation efficiency for both turbidity and organic matter removed. The optimum pH range for all of the coagulants investigated was around pH 7.0 under the experimental pH range of 4.0~9.5. Especially, the highest basicity PACl (r=2.2) and $FeCl_3$ were considered as more appropriate coagulants for the removal of turbidity in the case of raw water exhibiting higher pH.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2010.04a
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• pp.193-193
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• 2010

이전의 연구에서 우리는 선응집 기술을 적용한 중질탄산칼슘의 크기에 따른 수초지의 물성을 평가하였다. 이때 선응집 기술이 적용된 충전물의 입도와 분포를 측정하기 위해 light diffraction spectroscopy (LDS) 가 사용되었다. 경질탄산칼슘과 양이온성 고분자의 흡착 현상을 알아보기 위한 이번 연구에도 LDS가 사용되었으며, 일회성으로 입자의 크기와 분포를 측정하는 것에서 더 나아가 시간의 흐름에 따라 응집체의 형성과 파괴, 재성장을 관찰할 수 있는 도구로서 역할 하였다. 본 연구에서 우리는 세 가지 경우로 나누어 경질탄산칼슘의 응집 현상을 관찰하였다. 첫째로 경질탄산칼슘에 흡착되는 양이온성 고분자의 특성, 분자량과 전하밀도, 을 달리하여 응집체의 성장과 파괴를 관찰하였다. 둘째, 양이온성 고분자로 중질탄산칼슘을 응집시켜, 경질탄산칼슘 응집체의 경우와 입도와 전단 안정성 등을 비교하였다. 마지막으로 나노 크기의 실리카 투입이, 마이크로 크기의 경질탄산칼슘 응집체가 강한 전단에 의해 파괴되었을 때, 응집체의 전단 안정성이나 재성장 측면에 도움을 주는지 관찰하였다. 내첨용 충전물로써 경질탄산칼슘의 사용이 전 세계적으로 늘고 있는 시점에서 양이온성 고분자 첨가에 의한 경질탄산칼슘의 응집 현상을 관찰하는 것은 일반적인 제지 공정에서 경질탄산칼슘의 거동을 이해하는데 도움이 될 뿐만 아니라, 내첨용 충전물 첨가에 따른 종이의 강도 저하 방지를 위한 선응집 기술의 적용에도 도움이 될 수 있을 것으로 생각한다.

• Journal of Korea Water Resources Association
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• v.48 no.3
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• pp.233-243
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• 2015

The bimodal flocculation of cohesive sediments in water environments describes the aggregation and breakage process developing a bimodal floc size distribution with dense flocculi and floppy flocs. A two class population balance equation (TCPBE) was tested for simulating the bimodal flocculation by a model-data fitting analysis with two sets of experimental data (low and high turbulent flows) from 1-D flocculation-settling column tests. In contrast to the Single-Class PBE (SCPBE), the TCPBE could simulate interactions between flocculi and flocs and the flocculation mechanism by differential settling in a low turbulent flow. Also, the TCPBE could perform the same quality of simulation as the elaborate Multi-Class PBE (MCPBE), with a small number of floc size classes and differential equations. Thus, the TCPBE was proven to be the simplest model that is capable of simulating the bimodal flocculation of cohesive sediments in water environments and water, wastewater treatment systems.

• Proceedings of the Korean Information Science Society Conference
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• 2001.10a
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• pp.481-483
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• 2001

클래스의 응집도를 측정하기 위한 여러 연구들이 제안되었지만, 이런 연구들은 데이터 상호작용에 의해 응집도를 측정하므로 메소들간에 데이터 상호작용이 없지만 객체의 또 다른 속성들을인 데이터들이 함께속하는 경우를 고려하지 못하고 있다. 따라서 본 연구에서는 데이터 상호작용이 없는 경우를 고려하고, 또한 클래스 내의 멤버들과 멤버들간의 연결을 모두 고려하여 응집도를 측정할 수 있는 새로운 응집도 척도를인 강 클래스 응집도(Strong Class Cohesion: SCC)와 약 클래스 응집도(Weak Class Cohesion: WCC)를 제안하였다. 또한 기존 척도들과의 비교평가를 통해서 WCC와 SCC가 향상된 측정을 제시함을 보여 주었다.

• Journal of the Korea Organic Resources Recycling Association
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• v.12 no.2
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• pp.101-109
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• 2004

In this study, the solid-liquid separation characteristics of swine wastewater were investigated for the coagulation and dissolved air flotation (DAF). Coagulation characteristics were studied using jar-tester with the different coagulants and dosage amounts. DAF characteristics were also investigated in terms of the different flotation conditions with the raw swine wastewater, pH adjustment only, and adding coagulants. When the raw swine wastewater was coagulated with the only inorganic coagulants, the proper inorganic coagulants were founded as $FeCl_3$ > PAC > Alum orderly, and the optimal coagulant dosages were founded as $1,000mg/{\ell}$, $1,500mg/{\ell}$, $1,500mg/{\ell}$, respectively. As the raw swine wastewater was treated with the polymer coagulants, the only cationic polymer coagulant showed an effective coagulation and the optimal dosage of cationic coagulant was founded as $200mg/{\ell}$. When the different dosages of cationic polymer was added to each $500mg/{\ell}$ of the inorganic coagulants, the proper inorganic coagulants were founded as $FeCl_3$ > Alum > PAC orderly, and optimal cationic polymer dosages was founded as $25mg/{\ell}$, $25mg/{\ell}$, and $100mg/{\ell}$, respectively. Resulting from the raw swine wastewater experiments using DAF without coagulation, the proper operation conditions of DAF were set to 400% of recycling ratio, 4 atm in air dissolving tank, and under pH 3. But the raw swine wastewater was difficult to successfully operate DAF without pre-coagulation. While the DAF separation after pre-coagulation using inorganic coagulants was not accomplished due to the low intensity of the floc, DAF after pre-coagulation using both the inorganic and cationic polymer coagulants was accomplished very well. Optimal dosage of cationic polymer coagulant in case of $500mg/{\ell}$ Alum dosage was founded as $500mg/{\ell}$.

• Journal of Environmental Science International
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• v.4 no.4
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• pp.367-377
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• 1995

The study of flocculation kinetics is of fundamental interest in the field of water treatment, because rational study of the factors affecting the coagulation process should be based on the rate of particle growth. The effect of sulfate on flocculation kinetics were examined using ferric nitrate as a coagulant to coagulate kaolin clay in water under several experimental conditions. Both the particle size distribution data obtained from the AIA and the on-line measurement of turbidity fluctuation by the PDA were used to measure flocculation kinetics. Results show that sulfate ion added to the kaolin suspension played an important role in the flocculation process, not only improving flocculation kinetics at more acidic pH levels but also changing surface charge of particles. The kinetics of flocculation were improved mainly by the enhanced rate and extent of Fe(III) precipitation attributed to the addition of sulfate, and thereby, better interparticle collision frequency, but little by the charge reductions resulting from the sulfate addition. The increase in sulfate concentration beyond $3\times10^{-4}M (up to 2\times10^{-3}M)$ did not induce further improvement in flocculation kinetics, although the higher concentrations of sulfate ion substantially increased the negative ZP value of particles. Key Words : Flocculation Kinetics, Fe(III) Coagulant, Sulfate ion, Turbidity Fluctuation.