• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.859-863
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• 2008

축산폐수, 침출수 등의 고농도 폐수를 생물학적으로 처리할 경우 최종 방류수는 강한 색도를 띠며 고분자량의 유기물질을 다량 함유한다. 이는 생물학적으로 분해하기 어려운 유기성 복합체와 생화학적 반응에 의한 중간생성물로 색도를 띠는 천연유기물질(NOM)을 포함한다. 생물학적 처리수의 색도는 심미적인 불안감, 방류수역의 수질오염 및 공중보건상의 잠재적 위해성을 갖는다. 또한, 수자원 이용측면에서 정수처리공정에서의 약품투입량 증가와 특히, 소독부산물 생성이라는 잠재적 문제점이 뒤따른다. 따라서 이러한 문제점을 해소하기 위한 생물학적 2차 처리수의 후속처리가 요구되며, 실제로 난분해성 유기물과 색도를 제거하기 위한 흡착, 막 분리, 고급산화(AOP) 및 화학적 응집 등의 물리-화학적 공정에 대한 연구가 수행되어왔다. 특히, 화학적 응집은 무기응집제 또는 고분자중합체(Polymer)를 이용하여 콜로이드성 입자와 색도를 띠는 난분해성 유기물을 전기적 불안정화를 유도함으로서 흡착 및 응집과정을 통해 제거하는 공정으로 많은 연구자들에 의해 연구되어왔다. 그러나 난분해성 유기물과 색도제거는 대상원수의 성상과 화학적 특성 등에 따라 각각의 제거효율과 최적 운전조건이 상이하게 나타난다. 화학적 응집공정은 비교적 높은 제거효율을 보이지만, 운전 및 유지관리의 기술적 어려움, 경제적 비효율성 등으로 인하여 적용에 어려움을 겪고 있는 실정이다. 본 논문에서는 생물학적 혐기-호기성 공정에서 방류되는 축산폐수의 2차 처리수를 대상으로 화학적 응집에 의한 색도 및 난분해성 유기물의 제거거동을 고찰하였다. 대상 처리수의 $TCOD_{Cr}$ 농도는 평균 410 mg/L인 반면, $BOD_5$는 7-15 mg/L 범위로 난분해성 유기물을 다량 함유하고 있음을 알 수 있었다. 이에 황산알루미늄(Aluminium sulfate; $Al_2(SO_4){\cdot}14H_2O$)과 염화철(ferric chloride)의 무기응집제를 이용하여 자 테스트(jar test)를 수행한 결과, 동일한 응집제 주입량에서 염화철의 유기물 제거 효율이 높은 것으로 나타났다. 황산알루미늄과 염화철의 경우 각각의 응집제 주입율 5.85mM에서 89%, 7.03mM에서 97.5%의 최대 유기물 제거효율을 보여주었으며, 이 때 최종 pH는 4.0-5.6 범위이었다. 한편, 대상 원수 내의 콜로이드성 입자 또는 용존성 유기물의 작용기(functional group)는 일반적으로 음으로 하전 되어 있어 응집에 의해 잘 제거되지 않는 특성을 가지고 있다. 따라서 과량의 응집제를 주입하여 다가의 양이온성 금속염을 흡착시켜 전기적으로 중화시키고, 생성된 침전성 수화물 내에 포획 또는 여과시켜 제거하게 된다. 이 때, 금속염 수화종의 전하밀도가 응집효율에 영향을 주는 것으로 알려져 있는데, 다가의 양이온은 전기적 이중층(Double layer) 압축에 의한 불안정화를 향상시킬 수 있기 때문에다. 또한, 2가 금속염은 색도유발물질과 흡착하여 humate 또는 fulvate 등의 착화합물(complex)을 형성시켜 응집효율을 향상시킬 수 있다. 따라서 본 연구에서는 생물학적 2차 처리수의 화학적 응집처리에 있어서 알루미늄염 등의 다가이온 첨가가 응집에 미치는 영향을 관찰하고, 후속되는 플록형성 및 침전공정에 의한 제거효율을 비교, 평가함으로써 2차 처리수로부터 난분해성 유기물과 색도를 보다 효과적이고 경제적으로 제거할 수 있는 최적인자를 도출하고자 하였다.

• 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.

• Applied Biological Chemistry
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• v.41 no.6
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• pp.465-470
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• 1998

For the need of bio-degradable flocculant in stage of wastewater treatment, some cultural conditions of bioflocculant production were optimized with Aeromonas hydrophila KH-54. About 260 strains of type culture and bacteria isolated from marsh, pond, activated sludge, etc were examined for their ability to flocculate kaolin particles and swine wastewater. Among them, KH-54 showed the highest flocculating activity and was identified as Aeromonas hydrophila according to the cultural, morphological and physiological properties. The maximum production of the flocculant secreted by Aeromonas hydrophila KH-54 was observed in culture medium containing 2.0% mannitol, 0.05% ammonium chloride, 0.02% potassium phosphate dibasic, 0.01% $MgSO_4{\cdot}7H_2O$ and 0.05% yeast extract at initial pH 7.0 when cultured on rotary shaker controlled at $25^{\circ}C$ and 150 rpm. Under the optimized condition, the flocculating ability reached to 770 units/ml of kaolin flocculating activity and 81% of NTU removal efficiency against swine wastewater after 4 days cultivation. The bioflocculant was also effective on various organic wastewaters other than swine wastewater, showing NTU removal rate ranging from 92% to 34%.

• Journal of Life Science
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• v.29 no.3
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• pp.362-368
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• 2019

For the practical application and development of biopolymer flocculant Biopol32 produced by Pseudomonas sp. GP32, its flocculation effect on wastewater from food processing, slaughter houses, and the dyeing industry was investigated. In the food processing wastewater, Biopol32 led to a chemical oxygen demand (COD) reduction rate of 70% and a suspended solid (SS) removal rate of 49% at pH 6.0. In the slaughter house wastewater at pH 4.0, a COD reduction rate of 61% and SS removal rate of 91% were observed, and in the dyeing wastewater, the rates were 72% and 92%, respectively, at pH 5.0. The size of floc formed during the flocculation process was 10 mm at a final concentration of 20 ppm, and the dehydration efficiency was 62%. In both the bioflocculant Biopol32 group and a PAA synthetic flocculant group, optimal flocculant concentration that yielded the best overall dehydration efficiency was 20 ppm, and, at this concentration, the shortest filtration time to reach the natural critical moisture content of 78.1% was attained.

• KSBB Journal
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• v.11 no.4
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• pp.470-475
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• 1996

A white rot fungus as a microbial source producing bioflocculant was isolated from rotted leaves and identified as Pestalotiopsis sp. M01. The flocculating activity and productivity of Pestan produced by Pestalotiopsis sp. KCTC 8637P was determined by using Czapek-Dox medium as the inorganic salt source. The flocculating activity was highest at 3% sucrose and 0.3% $KN0_3$, pH 7, and $25^{\circ}C$, respectively. Whilst, the strain growth was highest at 3% sucrose, 0.3% TEX><$KN0_3$, pH 5, and $25^{\circ}C$, respectively.

• KSBB Journal
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• v.7 no.3
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• pp.166-171
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• 1992

Zoogloea ramigera 115 was cultured for biopolymer production and its bioflocculant usages. Cultural conditions of the organism were examined with regard to high production of the microbial polysaccharide. The most suitable medium was found to contain glucose as a carbon source, $NaNO_3$ as a nitrogen source, and yeast extract as an organic nutrient. The initial pH of 6.0 proved to optimal. The biopolymer was extracted effectively using ultrasonication and high speed centrifugation, followed by propanol addition. Jar test results indicate that the polysaccharide produced by the organism is an effective flocculant.

• KSBB Journal
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• v.10 no.4
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• pp.421-427
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• 1995

A fungal strain, designated Aspevgillus sp. JS-42, was isolated and shown to produce an extracellular polysaccharide used as a bioflocsulant. The optimal medium composition for the production of flocculant with Aspergillus sp. JS-42 was glucose 3.0%, yeast extract 0.2%, $(NH_4)_2S0_4 0.1%, CaCI_2.2H_2 0.05%$ in distilled water. The optimum culture temperature and optimum culture pH for the production of the flocculant were $25^{\circ}C$ and pH 7.0, respectively. The highest production of flocculant was observed after 90 hours of cultivation at the optimal condition. The flocculant could efficiently flocculaled the tested solids suspended in aqueous solution and was stable at high temperature($100^{\circ}C$) and to pH range of from 2 to 10. The flocculant seems to be a kind of high viscous polysaccharide.

• Korean Journal of Environmental Biology
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• v.19 no.2
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• pp.129-135
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• 2001

The effects of CellCaSi and bioflocculant on the control of algal bloom were investigated in enclosures in a small eutrophic pond. The bioflocculant produced by a bacterial strain S-2 was finally selected to remove Microcystis aeruginosa which was a dominant species of algal bloom in the pond. Enclosure experiment showed that phosphorus concentration decreased dramatically from $131\mu{g}\ell^{-1}$ (Control) to $1-14\mu{g}\ell^{-1}$ in three CellCaSi-enriched enclosures. Chlorophyll $-\alpha$ concentration also decreased from $215\mu{g}\ell^{-1}$ (Control) to $59\mu{g}\ell^{-1}$ by the addition of CellCaSi $(1g\ell^{-1}$, bioflocculant $(2ml\ell^{-1}$, calcium chloride $(1g\ell^{-1}$ and ferric chloride $(2mg\;Fe\ell^{-1})$ in Enclosure 4. From the results of the mouse acute toxicity test of the S-2 bioflocculant and the goldfish survival test in enclosures, it seems that both the S-2 bioflocculant and the CellCaSi do not show any severe toxicity in water system. Consequently, it was concluded that the bioflocculant and the CellCaSi could be used to control algal bloom in eutrophic waters by removing phosphorus and chlorophyll$-\alpha$.

• Journal of Forest and Environmental Science
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• v.17 no.1
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• pp.29-36
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• 2001

Compared to other industries, pulp and paper industry use a lot of water. As a result, a large amount of the waste water is discharged in the pulp and paper industry. This study was investigated to prevent the environmental pollution terribly faced with our society nowadays. In the waste water of pulp and paper, there are so many things in the waste water, like fiber, filler, and other organic solvent etc. so we must remove them from our environment. This study was investigated to experiment on test of impressed filtration with the kind and quantity of coagulant and the variance of pressure. In this study, we used feds, alums. $CaCl_2$, polymer as a coagulant and these pressure was 49, 98, 147, 196kpa. According to this study, we measured the speed of filtration and turbidity, measuring filtrated water. According to the values, we know the fact that as the consistency of coagulant and pressure were high, the filtration was good.

• Proceedings of the Membrane Society of Korea Conference
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• 1995.10a
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• pp.41-42
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• 1995

기존의 정수처리 공정은 응집-침전-급속여과처리를 주로 사용하면서 생물 활성탄처리-오존처리 등을 거치는 공정으로 이루어져 왔다. 그러나 응집제의 투여시 최적 응집제량, 최적 응집제 투여위치, 교반시간, pH 조절 등 번거러운 test가 선행 되어야 하며 처리수에 남아있는 응집제에 의해 2차 오염을 일으켜 침전조의 부지 면적에 따른 대형화등을 초래할 단점이 있다. 따라서 최근에는 이러한 단점을 보완하고 장치의 간소함, 높은 효율의 유지에 따른 후처리 공정의 부하감소 및 운전 조건 인자등의 감소라는 경제적 효과를 기대할 수 있는 막분리공정이 도입되었다. 그러나 분리막 처리공정의 경우 원수에 다량 포함되어 있는 콜로이드 입자들에 의한 flux의 감소 및 fouling 현상으로 인한 막의 수명감소, 처리수량의 감소 및 최적 설계 및 운전 방법등의 새로운 공정에 대한 많은 자료의 확보가 필요하다. 따라서 본 연구는 기존의 정수처리 공정에 있어서 전처리 부분에 해당하는 응집-침전-급속여과처리 공정을 분리막 공정으로 대체 하였을 때 분리막의 재질 및 module의 차이에 따른 처리 능력을 비교하고 각 단위 공정들에 의한 flux 변화, 각 공정별 수질분석, 회복율, 회수율 등을 검토하여 최적 조건의 공정을 확립하여 후처리 공정의 효율을 극대화 하는데 있다.