• 대한환경공학회지
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• 제28권2호
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• pp.216-222
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• 2006

본 연구에서는 국내에서 개발되어진 섬유사 필터의 충진밀도와 여과속도가 처리 효율에 미치는 영향에 대한 연구결과를 나타내었다. 0.93 mm의 직경을 가진 폴리아마이드 섬유사가 충진된 직경 40 cm, 높이 2 m의 pilot-scale 규모의 반응기에서 수행되었다. 충진밀도가 섬유사 여과기의 처리효율에 미치는 영향을 살펴보기 위해 여과속도를 325 m/hr로 고정하고 충진밀도를 $70kg/m^3$에서 $100kg/m^3$의 범위에서 운전하였으며, 이와 반대로 여과 속도가 섬유사 여과기의 처리효율에 미치는 영향을 연구하기 위해서 충진밀도를 $70kg/m^3$으로 고정시킨 뒤 여과속도를 65 m/hr에서 400 m/hr의 범위로 운전하였다. 충진밀도가 증가할수록 여과 압력은 기하급수적으로 증가하였다. 탁도 및 SS 제거효율은 $80kg/m^3$까지는 30% 이내의 낮은 제거효율을 나타내었으며, $100kg/m^3$에서도 50% 이하의 낮은 제거효율을 나타내었다. 여과속도에 따른 섬유사 여과기의 여과압력은 여과 속도와 비례적으로 증가하였다. 여과속도가 낮을수록 탁도와 SS의 제거효율도 증가하였으며 65 m/hr에서 73%의 제거 효율을 나타내었다. 전체적으로, 섬유사 여과기를 이용한 입자상 물질의 제거 효율을 개선하기 위해서는 충진 밀도 보다 여과속도를 유입수 특성에 따라 적절히 조절하는 것이 효과적인 것으로 나타났다.

• 한국입자에어로졸학회지
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• 제8권4호
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• pp.133-141
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• 2012

A new depth filter media was designed and samples of flat sheet as well as cartridge assembly were prepared and tested to evaluate the filtration performance and compare with the commercial product. The arrangement of the depth filter media layers is important to reach the optimal filtration parameters like filter pressure drop, particle collection efficiency and dust holding capacity. Initially, both flat sheet samples of new media and commercial product have been tested using standard test units. Tests with new depth filter media cartridges of various pleat count were conducted in order to find the optimal pleat count which would represent the lowest pressure drop. These tests give an insight on how the pleat count and the assembly configuration affect the performance of the depth filter media cartridge. By comparing the samples with a commercial product we could confirm relatively high filtration performance of the sample cartridge with pleat count 150 made of new depth filter media. The cartridge with the same pleat count exhibits better performance without the outer mesh.

• 한국자동차공학회논문집
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• 제15권1호
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• pp.78-88
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• 2007

In the present study a detailed examination of various porous media models for predicting filtration efficiency and pressure drop of diesel particulate filter (DPF), such as sphere-in-cell and constricted tube models, are attempted. In order for demonstrating their validities of correct estimation on permeability, geometry of property configurations common in commercial cordierite DPFs are correlated to the porous media flow models, and validations of predicted filtration efficiencies due to the use of different unit collectors are made with experiments. The result shows that the porosity, pore size and permeability of cordierite DPF can be successfully correlated by Kuwabara flow field with correction factor of 0.6. The unit collector efficiency predicted by sphere-in-cell model agrees very well with measurements in accumulation mode, whereas that by constricted tube model with significant prediction error.

• 멤브레인
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• 제30권2호
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• pp.131-137
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• 2020

본 연구에서는 가압식 분리막 여과에서 무기입자의 존재가 유기파울링에 미치는 영향을 관찰하였다. 유기파울링의 유발을 위해 알긴산나트륨(sodium alginate, SA)를 이용한 정밀여과 실험에서 무기 실리카(SiO₂) 입자의 존재 유무와 상관없이 분리막 파울링은 여과초기 완전공극막힘에서 여과시간이 경과할수록 케이크 형성에 의해 주로 지배되었다. 그러나 무기입자의 존재 시 정압여과에서 알긴산나트륨 파울링 케이크 비저항값과 압축성은 상대적으로 낮게 관찰되었고 이로 인해 낮은 파울링 속도가 관찰되었다. 동일한 시료를 이용한 정량여과 실험을 수행한 결과 정압여과에 비해 정량여과에서 여과초기 공극막힘현상 및 파울링 속도는 더욱 증가하였다. 이와 같은 현상은 파울링층이 지닌 압축성으로 막간차압의 증가 시 케이크 비저항값이 함께 증가하였기 때문인 것으로 판단된다. 알긴산나트륨과 실리카 입자가 함께 존재 시 알긴산나트륨이 단독으로 존재하는 것보다 수리학적 세정을 통한 파울링 제거효과는 더욱 좋은 것으로 관찰되었다.

• 대한환경공학회지
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• 제30권2호
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• pp.161-167
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• 2008

본 연구에서는 새로운 여과-투과(filtration-permeation) 실험 방법을 사용하여 여과실험에 영향을 미치는 인자 중 침전에 대한 영향을 입자현탁액과 플럭현탁액에 대해 각각 수행하였다. 그 결과 여과실험으로는 정확한 평균 비저항값을 예측할 수 없었으나, 투과실험으로 정확한 평균 비저항값을 측정할 수 있었다. 투과기간을 연장하였을 때 입자현탁액에서 형성된 케이크에서는 투과속도에 별다른 영향이 없었으나 플럭현탁액의 경우는 응집제의 쓸려나감 현상을 보였다. 또한 여과-투과 실험을 사용하여 투과시에 단계적으로 압력을 증가시킴으로써 단 한번의 실험에 의해 케이크의 압축성이 측정되어 질 수 있음을 보였으며, 이 방법을 응용하여 평균 비저항값이 큰 활성슬러지의 긴 여과시간을 짧게 줄여 측정하는 새로운 방법을 제안하였다.

• 상하수도학회지
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• 제22권4호
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• pp.445-448
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• 2008

The application of the membrane filtration process has been increased for the drinking water treatment system because of excellent quality of treated water compared with the sand filtration process. The selection of suitable pre-treatment processes and optimum flux according to the characteristics of raw water are important factors for the design of membrane processes. In this study, the most efficient pre-treatment processes for drinking water was selected by investigating the effects of pre-treatment processes on the operational stability of the membrane filtration process. Both lab-scale and pilot-scale experiments were conducted. In the lab-scale test, the effect of pre-treatment processes on the stability of the membrane filtration process was investigated indirectly by comparing the performance of membrane flux for raw water, pre-treated water, and membrane permeated water. In the pilot-scale test, the usefulness of prefiltration processes was assessed by comparing the performance of single membrane process and hybrid coagulation-membrane process. The results indicated that the coagulation process contributed to the stabilization of trans-membrane pressure (TMP) by removing contaminants on membranes, though the pre-filtration process had little effect on the TMP.

• 한국물환경학회지
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• 제18권2호
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• pp.221-228
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• 2002

Abundant growth of algae in raw water sources caused by eutrophication brings about significant side effects on water supply, such as taste and order problem, oxygen depletion, toxic material secretion, and filter clogging problem in water treatment process, etc. The purpose of this research is to remove the algae and phosphorus compounds in the Pal-dang reservoir promptly by using the upflow filtration system with coagulant addition. The filter tower consisted of sand media and sieve filter with air back-washing process. By using coagulation and filtration with $132{\mu}m$ pore size filter, about 55% and 70% of algae and phosphorus compounds were removed respectively. The experimental conditions were as follows; head loss of 0.2m, linear velocity of 200m/day, and filtration flux of 1000($L/m^2/day$). In the case of filtration with cartridge type filter of $25{\mu}m$ pore size, the filtration flux was about 7800 LMH, and the removal ratios of COD, SS, T-P, and Chlo-a. were 61%, 99%, 54%, and 98%, respectively. However, high pressure air back-washing process with should be required for the maintenance of such high filtration flux.

• 한국입자에어로졸학회지
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• 제18권1호
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• pp.9-21
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• 2022

In this study, a novel antiviral coating method for the air filtration system of subway station was investigated. Using dry aerosol coating process, we developed a high-performance antiviral air filter with spark discharger and carbon brush type ionizer. Silver nanoparticles were produced by a spark discharge generation system with ion injection system and were used as antiviral agents coated onto a medium grade air filter. The pressure drop, filtration efficiency, and antiviral ability of the filter against aerosolized MS2 virus particles as a surrogate of SARS-CoV-2 virus were tested with dust contamination. Dust contamination caused the increase of the filtration efficiency and pressure drop, while the antiviral agents (in this study, silver nanoparticles) coating did not have any significant effect on the filtration efficiency and pressure drop. Using these properties, we suggested a novel method to maximize the antiviral performance of the antiviral air filter that was contaminated by dust particles. Moreover theoretical analysis of antiviral ability with dust contamination and re-coated antiviral agents was carried out using a mathematical model to calculate the time-dependent antiviral effect of the filter under actual conditions of subway station. Our model can be used to apply on antiviral air filtration system of subway station for prevention of pandemic diffusion, and predict the life cycle of an antiviral filter.

• Environmental Engineering Research
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• 제19권1호
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• pp.1-8
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• 2014

Natural organic matter (NOM) is a primary component of fouling in low-pressure membrane filtration, either solely, or in concert with colloidal particles. Various preventive measures to interfere with NOM fouling have been developed and extensively tested, such as coagulation, oxidation, ion exchange, carbon adsorption, and mineral oxide adsorption. Therefore, this article aims to conduct a literature review covering the topics of low-pressure membrane processes, NOM characteristics and fouling behaviors, and diverse fouling control strategies. In-depth explanations and discussion are made regarding why some treatment options are able to remove NOM from source water, but do not reduce fouling. This review provides insight for hybridized membrane processes with respect to NOM removal and fouling mitigation in water treatment.

• 한국환경과학회지
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• 제9권2호
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• pp.173-176
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• 2000

This study was carried out to investigate the filtration characteristics of membrane modules according to hollow fiber dispersion for direct solid-liquid separation of activated sludge. 2 bundle, 4 bundle, and 10 bundle, and 10 bundle module used in this experiment according to hollow fiber dispersion was manufactured at laboratory and permeate flux and transmembrane pressure(TMP) of each module were observed under a suction pressure of 0.5kgf/c$m^2$. As the hollow fibers were dispersed, permeate flux was increased and TMP was decreased. Permeate flux and TMP of each module was 15.0 $\ell$/$m^2$.h and 31.8 cmHg for 2 bundle, 16.0 $\ell$/$m^2$ .h and 17.4 cmHg for 4 bundle, and 20.4 $\ell$/m2 .h and 31.8 cmHg for 10 bundle. In conclusion, the membrane fouling is expected to be decrease by maintaining lower TMP with hollow fiber dispersion.