• Proceedings of the Korean Environmental Sciences Society Conference
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• 2005.05a
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• pp.356-359
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• 2005

하수를 처리하는 공정에서 해마다 슬러지의 발생량은 증가하고 있으며, 이를 효과적으로 처리하는 것이 매우 중요하다. 따라서, 본 연구는 경제적이면서도 측정이 간편한CST(Cap-illary Suction Time)을 통해 슬러지 의 탈수성 과 적 정 주입량을 산출하는 방법을 연구하였다. 이를 위하여 본 실험의 대상인 도시 하수슬러지에 대하여 함수율 및 pH변화, 무기 및 유기 응집제의 주입량 변화, 그리고 응집제 투입 후 침전된 응집제량을 조사하여 탈수성을 조사하였다. 슬러지의 함수율을 97%, 98%, 99%로 했을 때, CST는 99%일 때가 가장 적은 값으로 나타났다 응집제 주입 후 침전된 슬러지의 생성량은 응집제가 증가됨에 따라 증가하다가, 최적 주입량보다 더 많은 응집제를 주입할 경우에는 그 양이 감소했다. 이는 형성된 응집물의 구조적 특성의 변화를 나타내고 있음을 알 수 있다. 위와 같은 실험 결과를 통해 CST는 수분이내(< Smin)에 슬러지의 탈수성을 신속하게 측정할 수 있는 방법이며 비교적 정확하게 측정할 수 있음을 알 수 있다. 뿐만 아니라 응집제의 최적 주입량 및 응집물의 구조적 특성을 평가하는 데에도 유용하게 사용할 수 있다.

• Journal of Forest and Environmental Science
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• v.22 no.1
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• pp.27-31
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• 2006

Sedimentation characteristics such as SS, COD removal efficiency of wastewater in the toilet paper mill using recycled paper were examined by zeta potential. Optimum dosage of coagulant were determined by turbidity, SS, COD and then equation for treatment efficiency was suggested. Mechanical strength of floc was determined by turbidity.

• 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.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.3
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• pp.2321-2327
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• 2015

Three coagulants, alum sulfate(alum), poly aluminum chloride(PAC) and poly aluminum silicate chloride (PASC), were used to remove low to high turbidity and TOC in surface and ground blended water. Laboratory experiments and pilot plant experiments were carried out to evaluate the optimal coagulant and its dosage. To determine the optimized coagulant and its dosage, the turbidity, TOC and pH were measured. The experimental results showed the best removal performance using PASC. The optimal dosage of PASC between 3-20 NTU was found to be 15 mg/L in the jar test. In the pilot test, a 15 mg/L PASC dosage was applied and resulted in the efficient removal of turbidity and TOC between 3.6-27 NTU. The removal efficiency of PASC increased with increasing turbidity and TOC.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.5
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• pp.790-795
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• 1995

Flocculant-producing microorganisms were isolated from soil samples using kaoline as the flocculating test material. One strain that had high flocculating activity among them was selected and identified as Arcuadendron sp. TS-49. The favorable medium for production of the flocculant was 3% glucose, 0.2% yeast extract, 0.1% $NH_4Cl$, 0.01% $MgSO_4$, and 0.05% $MnSO_4$ in 150ml of T.W. with initial pH 7.0.The optimum culture temperature and pH were $30^{\circ}C$ and pH 7.0, respectively. The flocculant activity was observed most highly after 4 to 5 days of cultivation at the optimum condition and decreased significantly with the lapse of cultivation time. The flocculant was produced constituently and seemed to be degraded for ressimilation during cultivation. The productivity achieved by this system was about ten-fold higher than that of scrrening mediuim. This bioflocculant flocculated all tested solids, including various microorganisms and organic/inorganic compounds. Several qualitative analyses of the bioflocculant showed that it was a kind of glycoprotein containing sugars and protein.

• The Korean Journal of Food And Nutrition
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• v.10 no.3
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• pp.295-301
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• 1997

Among 120 microorganisms isolated from soil, KF-67 was the best producer of flocculant and was examined for flocculating ability in the kaolin clay and CaCl2 suspension. KF-67 was identified to be a species belong to the genus Agrobacterium sp. The influence of components of the culture medium for flocculant production by Agrobacterium sp. KF-67 was studied. The favorable carbon and inorganic nitrogen source for production of the flocculant were glucose and NH4NO3 and their addition concentrations were 2% and 0.1%, respectively. Addition of the organic nitrogen such as yeast extract, peptone and inorganic salt such as CaCO3 significantly increased the production of flocculant. These result indicated that the production of flocculant by Agrobacterium sp. was significantly affected by both organic nitrogen and inorganic salt. The components of the optimum culture medium were 2% glucose, 0.1% NH4NO3, 0.01% yeast extract, 0.01% peptone, 0.04% CaCO3, 0.03% NaCl in initial pH 7.5 when cultured with rotary shaker controlled at 3$0^{\circ}C$ and 120 rpm. Under the optimum culture medium, flocculant production was highly improved about 76% than that isolation medium.

• Clean Technology
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• v.7 no.1
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• pp.27-34
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• 2001

The waste slurry generated from CMP process contains particulate and heavy metals. It is hard to treat the waste slurry by conventional treatment method because the particulates in the waste are too fine to be easily separated the solid from the waste for the purpose of water recycling. The investigation was focused on finding the optimum condition of coagulation with two different coagulants. When the solid content in the waste slurry solution was 0.1wt%, the optimal ranges of pH and PACl concentration were 4~6 and 20~50 mg/L, respectively. When the solid content was increased to 0.5wt%, the optimal condition was 4~5 for pH and 50~100 mg/L for PACl concentration.

• Journal of Korean Society of Environmental Engineers
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• v.39 no.12
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• pp.689-697
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• 2017

As a fundamental study to apply the new flocculation method using ballast in water treatment process, the optimal conditions for general and ballast coagulant dosage, and pH, which are known to have a significant influence, were derived by response surface methodology. Poly aluminum chloride (PAC) and magnetite ballast were used as a general coagulant and ballast, respectively. Coagulation experiments were performed by jar-tester using the kaolin based synthetic water. The effects of three independent variables (pH, PAC, and ballast) on response variables (turbidity removal rate and average settling velocity of flocs) and the optimum condition of independent variables to induce the optimum flocculation were obtained by 17 experimental conditions designed by Box-Behnken procedure. After performing experiments, the quadratic regression model was derived for each of response variables, and the response surface analysis was conducted to explore the correlation between independent variables and response variables. The $R^2$ values for the turbidity removal rate and the average settling velocity were 0.9909 and 0.8295, respectively. The optimal conditions of independent variables were 7.4 of pH, 38 mg/L of PAC and 1,000 mg/L of ballast. Under these conditions, the turbidity removal rate was more than 97% and the average settling velocity exceeded 35 m/h.

• 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.

• Journal of the Korean Society for Environmental Technology
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• v.19 no.6
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• pp.563-569
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• 2018

The efficiency of wastewater treatment using microalgae was investigated in this study, focusing on nutrients and flocculation. In the experiments for reducing nutrients by incubation of microalgae, the total phosphorus and total nitrogen were removed over 92 % and 99 %, respectively. The higher flocculation rates as the average values 94% of Poly Aluminum Chloride(PAC) and 92 % of $FeCl_3$ were presented for the flocculation experiments under the conditions of Auto-flocculation and various additives. Also, the optimal(minimal) concentrations for over 90 % of flocculation were 30 mg/L and 40 mg/L for PAC and $FeCl_3$, respectively.