• Journal of Korean Society for Atmospheric Environment
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• v.11 no.E
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• pp.45-54
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• 1995

Indoor air quality models are useful to predict indoor air pollutant concentrations as a function of several indoor factors. Indoor air quality model was developed to evaluate the pollutant removal efficiency of variable-air-volume/bypass filtration system (VAV/BPFS) compared with the conventional variable-air-volume (VAV) system. This model provides relative pollutant removal effectiveness of VAV/BPFS by concentration ratio between the conventional VAV system and VAV/BPFS. The predictions agree closely, from 5 to 10 percent, with the measured values for each energy load. As a results, we recommend the VAV/BPFS is a promising alternative to conventional VAV system because it is capable of reducing indoor air pollutant concentration and maintaining good indoor air quality.

• Proceedings of the KSR Conference
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• 2004.06a
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• pp.177-182
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• 2004

Railroad car is one of major public transportation because of an increase in population and heavy traffic problems. We design the concept with air filtration of HVAC system using CFD, select environment-friendly components and compose intellectual HVAC system. For this object, the research to connect HVAC system which control temperature, humidity, air flow with pollutant controlling system which can deal with particular dust, nasty smell. In case of train, fresh air should be provided continuously for pleasant environment of the cabin every season. The air will control outer dust, inner particular dust, $CO_2$ density by air conditioning, heating, humidity regulating, air filtering and ventilating. Ventilation system on passenger cars should be designed for the health and comfort of the passengers.

• Journal of Korean Society of Water and Wastewater
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• v.31 no.6
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• pp.501-510
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• 2017

In this study, it is estimated that ceramic membrane process which can operate stably in harsh conditions replacing existing organic membrane connected with coagulation, sedimentation etc.. Jar-test was conducted by using artificial raw water containing kaolin and humic acid. It was observed that coagulant (A-PAC, 10.6%) 4mg/l is the optimal dose. As a results of evaluation of membrane single filtration process (A), coagulation-membrane filtration process (B) and coagulation-sedimentation-membrane filtration process (C), TMP variation is stable regardless of in Flux $2m^3/m^2{\cdot}day$. But in Flux $5m^3/m^2{\cdot}day$, it show change of 1-89.3 kpa by process. TMP of process (B) and (C) is increased 11.8, 0.6 kpa each. But, the (A) showed the greatest change of TMP. When evaluate (A) and (C) in Flux $10m^3/m^2{\cdot}day$, TMP of (A) stopped operation being exceeded 120 kpa in 20 minutes. On the other hand, TMP of (C) is increased only 3 kpa in 120 minutes. Through this, membrane filtration process can be operated stably by using the linkage between the pretreatment process and the ceramic membrane filtration process. Turbidity of treated water remained under 0.1 NTU regardless of flux condition and DOC and $UV_{254}$ showed a removal rate of 65-85%, 95% more each at process connected with pretreatment. Physical cleaning was carried out using water and air of 500kpa to show the recovery of pollutants formed on membrane surface by filtration. In (A) process, TMP has increased rapidly and decreased the recovery by physical cleaning as the flux rises. This means that contamination on membrane surface is irreversible fouling difficult to recover by using physical cleaning. Process (B) and (C) are observed high recovery rate of 60% more in high flux and especially recovery rate of process (B) is the highest at 95.8%. This can be judged that the coagulation flocs in the raw water formed cake layer with irreversible fouling and are favorable to physical cleaning. As a result of estimation, observe that ceramic membrane filtration connected with pretreatment improves efficiency of filtration and recovery rate of physical cleaning. And ceramic membrane which is possible to operate in the higher flux than organic membrane can be reduce the area of water purification facilities and secure a stable quantity of water by connecting the ceramic membrane with pretreatment process.

• Journal of Korean Society for Atmospheric Environment
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• v.19 no.1
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• pp.101-112
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• 2003

Biological methods are frequently used for treatment of contaminated air, containing volatile organic compounds and odor compounds in low concentrations and high flow rate of air streams. For more than 20 years. biofilter has been recognized as a cost effective technology for the purification of contaminated air. Most commercial applications before 1990 were for control of odors. In the past decades major progress has been accomplished in the development of vapor phase bioreactor. in particular biotrickling filers. Biotrickling filters are more complex than biofilters. but are usually more effective, especially for the treatment of compounds which are difficult to degrade or compounds that generate acidic by-products. While the level of understanding of biotrickling filtration process for VOCs still remains limited. the evidence success of biotreatment of VOC in air resulted in pursuing active research. This paper presents fundamental and practical aspert of VOCs treatment from air in biotrickling filter. Special emphasis is given to the operating parameters and the factors influencing performance for biotrickling filter.

• Membrane Journal
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• v.29 no.4
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• pp.216-222
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• 2019

In this study, permeation experiments were conducted using naturally circulating spherical beads, backwashable plate membrane and the air supplied from the bottom of the MBR. The activated sludge solution was maintained at 8,000 mg/L of MLSS and compared transmembrane pressure (TMP) with respect to FR (filtration and relaxation), FR/BW (filtration and relaxation/backwashing), SFCO (sinusoidal filtration continuous operation) and SFCO/BW (sinusoidal filtration continuous operation/backwashing). As the backwashing flux decreased from 47 to $14L/m^2{\cdot}hr$, the TMP increased generally, but the TMP of FR system increased significantly comparing with SFCO. In addition, the backwashing method reduced more TMP comparing to the cleaning method using spherical beads, and it was confirmed that the operation method using the spherical beads and the backwashing simultaneously is more effective than each method.

• The Journal of Engineering Geology
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• v.19 no.3
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• pp.389-400
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• 2009

Iron and manganese contents are usually over the limit of drinking water standard (0.3 mg/L) in unconsolidated aquifer of river bank filtration site in Nakdong river. Surge block and air surging techniques used in this study are useful tools to remove the slime within gravels and pebbles, to increase permeability of aquifer, to provide oxygen into aquifer, and to discharge iron and manganese oxides from a well. Surging activity brought about $5{\sim}8$ and $5{\sim}9$ times decreases in $Fe_{(total)}$ and $Fe^{2+}$ contents, and also 10 times decrease in $Mn^{2+}$ contents compared to non-surging condition, respectively. Additionally, iron oxide and manganese oxide increased up $1{\sim}1.2$ times after surging. This result shows that air injection into the aquifer can help iron and manganese content decreased and in-situ treatment technology needs to be introduced in river bank filtration project in South Korea.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2008.10a
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• pp.437-439
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• 2008

• Proceedings of the SAREK Conference
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• 2007.06a
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• pp.214-214
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• 2007

• Proceedings of the SAREK Conference
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• 2006.06a
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• pp.429-435
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• 2006

In this study multi-zone modeling program CONTAM 2.4 which is developed by NIST is used for modeling the air disinfection system which is consist of dilution, filtration, ultra violet germicidal irradiation (UVGI) for removing the indoor microorganism such as bacteria and fungus. Developed models those protect occupants against indoor microorganism generated in our daily life are enable to use for immune building simulation tool. Also, results indicate that those models are enable to compute the real situation that is almost impossible of carrying out experiment and identify the disinfection rate with highly reliance. Results also suggest that engineers will use these models as a design tool for the immune building system.

• Journal of Korean Society on Water Environment
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• v.31 no.5
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• pp.523-532
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• 2015

Hydrocyclone is widely used in industry, for its simple design, high capacity, low maintenance and low operational cost. The objective of this study is to develop hydrocyclone coagulation and filtration system. The system is made of hydrocyclone ballasted coagulation with polyaluminium chloride silicate (PACS) and upflow filter to treat micro particles in urban storm runoff. Roadside sediment particles (< $200{\mu}m$) was mixed with tap water to make various turbid suspensions to simulate urban storm runoff. The filter cartridge was filled with polyethylene media system and ran 1hr per everyday and total operation time were 8.19hrs and backwashing everyday after end of operation. The operation condition of flowrate was $8.2{\sim}11.9m^3/day$ (mean $10.1m^3/day$) and surface overflow rate (SOR) based on filter surface area was $45.5{\sim}65.9m^3/m^2/day$ (mean $55.7m^3/m^2/day$). The range of PACS dosage concentration was 14.0~31.5 mg/L. As the results of operation, the range of removal efficiency of turbidity, SS were 81.0~95.8% (mean 89.5%) 81.8~99.0% (mean 91.4%), respectively. An increase of filtration basin retention time brought on increased of removal efficiency of turbidity and SS, and increase of SOR brought on decreased of removal efficiency. During the first flush in urban area, storm runoff have an high concentration of SS (200~600 mg/L) and the filtration bed becomes clogged and decreased of removal efficiency. Backwashing begins when the drainage pipe valve at the filtration tank bottom is completely open (backwashing stage 1). Backwashing stage 2 was using air bubbles and water jet washing the media for 5 mins and open the drainage valve. After backwashing stage 1, 2, 61.83~64.04%, 18.53~27.51% of SS loading was discharged from filtration tank, respectively. Discharged SS loading from effluent was 7.12~14.79% and the range of residual SS loading in fliter was 2.26~5.00%. The backwashing effects for turbidity, SS were 89.5%, 91.4%, respectively. The hydrocyclone coagulation and filtration with backwashing system, which came out to solve the problems of the costly exchange filter media, and low efficiency of removing micro particles of filter type nonpoint treatment devices, is considered as an alternative system.