• 산업기술연구
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• 제20권A호
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• pp.113-122
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• 2000

Column tests in the laboratory were preformed to investigate characteristics of settling process of dredged soil sampled from in-situ. Test results were analyzed by using the existing theories on discrete settling and hindered settling. From column tests of monitoring the interface with time, settling was found to be a linear process with time and the settling rate was increased with initial water content of slurry. The settling rate was also observed to decrease with increasing initial height of slurry. Most of settling process were composed of flocculation, hindered settling and self-weight consolidation. On the other hands, flocculation of soil during settling was observed and it was found that the size and density of flocculated particles could be analyzed by using the method proposed by Richardson and Zaki.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2001년도 추계학술발표대회
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• pp.374-377
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• 2001

답토에서 분리한 균주는 Candida sp. HY200이라 임시 명명하였고, Candida tropocalis 보다 짧은 시간에 xylose를 소모하고, 당내성이 우수하며, flocculation의 특성을 갖고 있다. 260 g/L의 고농도 xylose 배지에서 xylitol 발효는 수율 79%, 생산성 2.14 g/L ${\cdot}$ h의 결과를 얻었다.

• KSBB Journal
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• 제16권3호
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• pp.225-232
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• 2001

미생물 세표표면의 소수성은 다른 미생물과의 flocculation, 액상이나 고형물질에 부착하거나 수용액에서의 부유현상 (floatation)과 같이 미생물과 다양한 물질사이의 표면 반응에 관여한다. 이러한 점에서 미생물 세포의 소수성은 의학분야 뿐만 아니라 생물공학의 다양한 분야에서 중요한 의미를 갖는다. 이 총설에서논 미생물 세포표면의 소수성과 관련된 특성과 물질, 그리고 세포표면의 소수성을 이용한 예를 중점적으로 기술하였다.

• 환경위생공학
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• 제15권1호
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• pp.7-13
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• 2000

To develop the removal technique of algal bloom the efficiencies of algal flocculation/ autoflotation by the kinds of coagulant and oversaturated oxygen concentration were investigated. The summarized results are as follow. 1. In the algae flocculation test with alum[$Al_2(SO_4)_3{\cdot}18H_2O$], optimum pH was 5.5 and, with chitosan optimum pH was 7.0. 2. Chitosan which was natural polymer showed the 5~10 times higher algal biomass flocculation efficiency than alum in the condition of same algal concentration. 3. For the each coagulant, the higher ${\Delta}DO$(oversaturated dissolved oxygen concentration - saturated dissolved oxygen) was, the faster the rising velocity of the algal floc was. 4. In the condition of about 4mg/L ${\Delta}DO$, the rising velocity of chitosan is about 2 times higher than that of alum, and chitosan formed the stronger algal floc.

• Environmental Engineering Research
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• 제16권4호
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• pp.237-242
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• 2011

In this study, three pilot-scale plants with the capacity 30 $m^3$/day were designed and set up to treat reservoir water for the production of drinking water. Three treatment processes were compared in the pilot testing: process 1 (coagulation- flocculation- sedimentationsand filtration- ozone- BAC); process 2 (coagulation- flocculation- sedimentation- microfiltration-ozone- BAC); and process 3 (coagulation- flocculation- sedimentation- sand filtration- GAC). The quality of water has been evaluated on the basis of selected parameters such as turbidity, color, consumption of $KMnO_4$, dissolved organic carbon (DOC), trihalomethane formation potential (THMFP), geosmin and 2-MIB. A detailed assessment of performance was carried out during a five months operation. Process 2 was found to have better removal efficiency of DOC, THMFP, geosmin and 2-MIB than process 1 and process 3 under identical conditions, although the removal rate of color was found to be the same in the three cases.

• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 1999년도 추계학술발표논문집
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• pp.205-214
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• 1999

In order to investigate the influencing factors of flotation fractionation. flotations were performed at varied conditions. The selectivity of fines fractionation is mainly affected by long fibers flocculating degree and if it were not for sufficient flocculation of long fibers, increase of long fibers loss could not be avoided. The amount of flotation reject totally depends on the stability of forth floated on the stock surface. only the small size fines stabilize the froth as they hinder the drainage of liquid lamella in flotation-froth. Two important factors of flotation conditions are improving the flocculation of long fibers and increasing the amount of flotation reject. Changing a flotation flux or an air-mixing ratio with aims of increasing the flocculation of fibers and reject ratios is in conflict. In order to satisfy the both conditions for reducing long fiber loss and for increasing flotation reject a new fractionation promoter is urgently required.

• 한국해양공학회지
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• 제12권2호통권28호
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• pp.111-120
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• 1998

Laboratory settling experiments (column, recirculating flume) were conducted for further understanding of the physical processes of cohesive sediment transport. \In still water experiments, the growth rate of flocculation is dependent upon the initial suspended concentration. Consequently, the settling velocity increases with concentration of flees. In flocculation settling regime, the exponent n in the settling velocity, $w_s=kC^n$, for Nakdong estuary mud was obtained empirically. The exponents were found to be 1.33, and 1.06 for the initial suspended concentrations of 1 g/i and 3 g/t, respectively. In flowing water, experiments for the median settling velocity with Nakdong mud in a recirculating flume were conducted. Settling velocity was found to depend much more strongly on the current velocity than initial concentrations. The temporal variation of suspended concentration increases as current velocity decreases.

• 상하수도학회지
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• 제14권4호
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• pp.337-342
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• 2000

In water treatment plants, open channel is used to distribute incoming flow to parallel treatment unit, such as flocculation basin and sedimentation basin. These control devices must be designed so that the incoming flow evenly distributed to the process unit. this is important in the view of optimizing process unit. In the recent past. significant insights into the sedimentation process have been developed. In this study, the 2-D computer program is developed to investigate fluid flow field and velocity vectors in flocculation sedimentation inlet distribution weir and calculate flow rates in each inlet weir. The specific purpose of this study is to analyze physical design factors, such as now rates, shape of channel, tapered angle in tapered type channel and main channel width.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 B
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• pp.952-954
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• 2000

In the cleaning-water treatment process, the flocculation machine is operated by the V.S motor when the coagulation-facility of the coagulation-process is operated. But after the flocculation machine is stopped by an instantaneous power failure, the transient takes place when the coagulation facility is re-started. To improve the transient state, we developed the reinforcement-circuit which had the function of soft-start and adapted to the field. As a result of this study, we reduced the damage of facilities and had the safety in maintaining the quality of water and improved the efficiency in the maintenance and the management.

• Geomechanics and Engineering
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• 제12권5호
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• pp.753-770
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• 2017

The coagulation or flocculation of cohesive clay suspensions is one of the most widely used treatment technologies for contaminated water. Flocculated clay can transport pollutants and nutrients in ground water. Coagulants are used to accelerate these mechanisms. However, existing coagulants (e.g., polyacrylamide, polyaluminum chloride) are known to have harmful effects in the environment and on human health. As an alternative, eco-friendly coagulant, this study suggests ${\varepsilon}-polylysine$, a cationic biopolymer fermented by Streptomyces. A series of sedimentation experiments for various ${\varepsilon}-polylysine$ concentrations were performed, and the efficiency of sedimentation with ${\varepsilon}-polylysine$ was estimated by microscopic observation and light absorbance measurements. Two types of sedimentation were observed in the experiments: accumulation sedimentation (at 0.15%, 0.20%, 0.25% ${\varepsilon}-polylysine$) and flocculation sedimentation (at 0%, 0.1%, 0.5%, 1.0%, 2.0% ${\varepsilon}-polylysine$). These sedimentation types occur as a result of the concentration of counter ions. Additionally, the performance of ${\varepsilon}-polylysine$ was compared with that of a previously used environmentally friendly coagulant, chitosan. The obtained results indicate that flocculation sedimentation is appropriate for contamination removal and that ${\varepsilon}-polylysine$ functions more efficiently for clay removal than chitosan. From the experiments and analysis, this paper finds that polylysine is an alternative eco-friendly coagulant for removing chemical contaminants in groundwater.