• KSCE Journal of Civil and Environmental Engineering Research
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• v.12 no.2
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• pp.285-291
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• 1992

The purpose of this research, through kinetic analyses and pilot plant experimentation of biofilm filtration reactor, is to study the theoretical equation of head loss in the Biofilm Reactor. The Head loss in the biofilm reactor has occurred due to the biofilm growth and the adhesion to the media surface and stagnation of upflow air bubble, which have caused the pore spaces to become smaller. On a basis of the head loss theory of sand filtration, therefore, the following equation of head loss for the biofilm reactor was proposed from this research results and proved to be possible to apply the equation for practical design of the biofilm filter. $h={\frac{h_o}{L}}{\int}^L_00.58\exp[-4.5){\sigma}_B)][{\frac{1-{\varepsilon}_o+({\sigma}_B)}{1-{\varepsilon}_o}}]^2{[\frac{{\varepsilon}_o}{{\varepsilon}_o-({{\varepsilon}_B)}}]^3dz$ here ${\sigma}_B=0.130+0.001{\theta}$.

• KSBB Journal
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• v.22 no.4
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• pp.197-200
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• 2007

This study examined the conditions of filtration and concentration of methanol extract from biomass. Filtration efficiency was improved by adding diatomaceous earth as a filter aid. The optimal amount of diatomaceous earth was 6% (w/w) to reduce the filtration time. The filtration time was reduced by 4.2% in first extraction, 30.0% in second extraction, 22.8% in third extraction, and 19.0% in fourth extraction, respectively. The optimal temperature of water bath was below 50$^{\circ}C$ for preventing paclitaxel degradation during concentration of methanol extract using a rotary evaporator. The temperature of concentrated solution in rotary evaporator was relatively low compared to bath temperature because of latent heat of evaporation. The stopping point of concentration in rotary evaporator for the following step was at a specific gravity of 0.96 of the concentrated solution in terms of the purity and yield of paclitaxel. This information is very useful for mass extraction of biomass for the recovery of paclitaxel from plant cell culture.

• Korean Chemical Engineering Research
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• v.50 no.3
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• pp.535-544
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• 2012

Filtration on horizontal filter medium facing upward is accompanied by sedimentation. When sedimentation phenomenon is not considered, the average specific cake resistance by filtration could be in error more than two times. In the previous paper on this subject, it was insisted that the solid mass fraction of suspension changes in filtration period by sedimentation. But we could not find out the degree of change. At the first half of this paper, the average specific cake resistance measured by permeation will be proved to be exact in several means. The average specific cake resistance conventionally measured by filtration does not give correct results because it uses initial solid mass fraction of suspension. Then we calculated the changed solid mass fraction of suspension due to sedimentation during filtration by the experimental values obtained "filtration-permeation" method. We also determined the solid mass fraction at a certain moment of filtration from the suspension height and a new equation derived in this study. The two results were compared and proven that they almost matched.

• Proceedings of the Korea Water Resources Association Conference
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• 2017.05a
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• pp.475-475
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• 2017

본 연구는 급변하는 기후변화에 대응하기 위한 이동식 전처리 여과취수장치 및 이를 이용한 물 생산용 취수시스템에 관한 것으로 홍수시나 가뭄시 이물질과 부유물질의 제거를 통해 후속 여과 장치의 부하 경감과 여과 효율의 극대화를 꾀할 수 있고, 필요시 비상용수 및 생활용수로 신속히 활용할 수 있는 시설에 관한 것이다. 기존 이동식 물생산장치의 수처리 공정은 1NTU 내외의 깨끗한 물이 유입되지 않으면 여과기(RO SYSTEM) 막이 폐색되어 생산된 물의 수질이 일정치 않아 재난 시 활용하는데 어려움이 있었다. 반면에 본 연구의 물 생산용 취수시스템은 전처리 여과취수를 통해 이물질과 부유물질의 제거가 가능하여 후속 여과 장치의 부하 경감을 통해 유지관리비용 최소화와 여과 효율의 극대화를 꾀할 수 있고, 필요시 신속히 생활용수로 활용할 수 있으며, 다양한 급수원(하천, 저수지, 댐, 지하수 등)을 통한 수량 확보가 가능하고, 평상시 다용도(하천정화, 녹조제거, 도로 청소, 조경수 등)로 사용이 가능한 물생산시스템이다. 또한, 비상시 이동식 차량에 탑재하여 이동 및 운반이 가능할뿐만 아니라 저수지나 댐 또는 하천 등의 원수를 취수하여 이중 관 구조의 여과기를 통한 전처리로 지속적인 여과력을 발휘하여 이물질이나 부유물질을 신속히 제거하고, 역세척수 공급으로 여과재를 쉽게 역세척할 수 있어 여과 성능의 저하를 방지할 수 있다. 본 연구에서의 이동식 전처리 여과취수장치는 다양한 조건에서의 수치모의를 수행하여 평상시나 비상시 다용도의 필요수량을 확보할 수 있도록 장치의 최적화를 수행하였으며, 이를 통해 안정적인 수자원 확보와 활용이 가능하고, 국내 물 시장에서 물생산시스템의 다양성을 확보하여 국민경제에 기여할 수 있고, 향후 물 부족 국가의 ODA 사업에 진출하여 수출증대 효과를 얻을 수 있을 것이다.

• Journal of the Korea Organic Resources Recycling Association
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• v.21 no.1
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• pp.53-61
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• 2013

The characteristics of methane production from pig manure slurry was investigated using anaerobic digestor combined with compost filtration bed. In this study, raw pig manure slurry was digested in mesophilic rectangular digester (effective volume $250m^3$) for 25 days and anaerobic digestion wastewater was filtered through compost filtration bed, which is composed of double layer, sawdust and chaff. The characteristics of anaerobic digestion wastewater were BOD 1,800 mg/L, COD 3,500 mg/L, SS 11,800 mg/L, T-N 1,200 mg/L and T-P 350 mg/L. After the filtration process, the contents of BOD, COD, SS, T-N and T-P of the anaerobic digestion wastewater were reduced by 97%, 62%, 89%, 39% and 57%, respectively. The concentrations of N, $P_2O_5$, and $K_2O$ of the leachate were 1,024, 111 and 407 mg/L, respectively. However, there was no odor emitted from the leachate.

• Korean Chemical Engineering Research
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• v.44 no.5
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• pp.468-475
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• 2006

For the filtration of super compactible cake, the high filtration pressure can not improve filtration rate. As the high pressure, in this case, decreases the cake porosity adjacent to filter medium and thus forms 'dense skin' which decreases the rate of liquid flow in a great extent. Actually, there was no method to improve filtration rate for the filtration with super compactible cake. We propose the saturation of $CO_2$ gas into the suspension before the filtration operation for improving the filtration rate. The dissolved $CO_2$ gas transforms itself into gas phase in the dense skin through which the pressure changes dramatically. The gas secures its space inside the dense skin, and finally forms the flow passages which improve the filtration rate.

• Journal of Aquaculture
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• v.18 no.4
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• pp.280-286
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• 2005

Experiments were conducted to examine the differences in ammonia removal rates with the different filter media between sand and zeolite, the expanding rates between $50\%$ and $100\%$, the water temperatures between $15^{\circ}C$ and $25^{\circ}C$, and the ammonia loading rates between 2 mg/L and 5 mg/L in the seawater fluidized bed filters system (FBF). The 2.1 m high FBF (8.3 cm diameter) consisted of the clear acrylic for the upper half and a PVC pipe for the lower half, Sand and zeolite were used as the filter media in sizes of 0.5$\pm$0.1mm. Each biofilter contained 5.4 L of media. The ammonia removal rates of the biofilter were higher at the $25^{\circ}C$ water temperature than those of the biofilter at $15^{\circ}C$ water temperature, and higher at the $50\%$ expanding rate of filter media than those of the biofilter at $100\%$ expanding rate of filter media. Also, the ammonia removal rates of FBF were higher at 5 mg/L ammonia concentration than those of FBF at 2 mg/L ammonia concentration in rearing water. With these better conditions the ammonia removal rates of FBF per day are practically acceptable and ranged ken 80.6 to $210.6g/m^3$.

• Journal of Korean Society of Environmental Engineers
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• v.39 no.7
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• pp.391-402
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• 2017

Particulate matter becomes an important issue in the environmental society recently so that it is necessary to evaluate that the commercial application of baghouse systems for effective control of fine particulates is viable. A laboratory-scale baghouse experimental apparatus with filter bags made of PTFE felt or PTFE felt coated with PTFE membrane is used to investigate the filtration performances of fine particulates. Experiments by changing filtration velocity, inlet dust concentration, and average dust particle size show that the dust collection efficiency becomes higher at lower filtration velocity, higher inlet dust concentration and larger average dust particle size. The total pressure drop through the filter media and dust layer becomes higher at higher filtration velocity and higher inlet dust concentration. The dust collection efficiency is higher and the pressure drop is lower at a baghouse with filter bags coated with PTFE membrane than that without membrane coating. From the result that the dust collection efficiency of $PM_{2.5}$ in a reasonable filtration velocity range during off-line pulsing at a baghouse with PTFE felt bag filters coated with PTFE membrane is as high as 99.99%, it is confirmed that the use of baghouse is an effective measure to control the fine particulates.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.5
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• pp.919-926
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• 2000

The experiment in this study was conducted as a part of an effort to evaluate filter performance with pilot-filters consisting of one mono-media and two dual-media columns. Particle distribution analysis using a particle counter is more sensitive and better than turbidity analysis in observing particle detachments and a breakthrough. In sand media filters having 1.5 m of available head, caution is needed in the head loss of the late stages of filtration, and for dual-media filters, appropriate media configuration and effluent Quality monitoring should be used for preventing the final breakthrough. Also the time of particle breakthrough in the dual media filter can be deferred by increasing bed depth, and it is necessary to use a filtration aid prior to filtration to prevent breakthrough of these intermediate sized particles in high filtration rate.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.2
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• pp.149-156
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• 2017

Nuclear fuel requires high reliability and safety and therefore contains debris filtering devices to prevent failure-inducing debris from entering it. The debris filtering performance of nuclear fuel is one of the most important factors for fuel integrity. Therefore, the performance must be evaluated and the measurement must be reasonable. In this study, a calculation method of the comprehensive filtering efficiency using the weighted mean was proposed to establish a standard filtering efficiency index. To confirm the suitability of the proposed method, representative debris specimens were selected and the filtering efficiency with the weighted mean was compared with the efficiency of the arithmetic mean. The weighting factor of the weighted mean was introduced to produce a fair evaluation. In addition, the analysis of the debris filtering mechanism was performed according to the size of debris specimens, and the main dimensions of the filtering feature for commercial nuclear fuel.