• Journal of Korean Society of Water and Wastewater
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• v.23 no.5
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• pp.539-545
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• 2009

A feasibility of a pilot scale two-phase anaerobic digestion with ultra filtration system treating garbage leachate were evaluated. The treatment system consisted of a thermophilic acidogenic reactor, a mesophilic methanogenic reactor, and an UF membrane. The average COD removal efficiency of the treatment system was 95% up to the OLR of 3.1 g COD/L/d. The higher COD removal efficiency with membrane unit resulted from the removal of some portion of soluble organics by membrane as well as particulate materials. When the membrane unit was in operation, bulk liquid in acidogenic and methanogenic reactors was partially interchanged, which maintained the acidogenic reactor pH over 5.0 without external chemical addition. Also, with the production of methane in the acidogenic reactor, the organic loading rate of the methanogenic reactor reduced. The initial flux of the membrane unit was $50{\sim}60L/m^2/hr$, but decreased to $5 L/m^2/hr$ after 95 days of operation due to clogging caused by particulate materials such as fibrous materials in garbage leachate. To prevent clogging caused by particulate materials, a pretreatment system such as screening is required. With the improvement with membrane unit operation, the two-phase anaerobic digestion with ultra filtration system is expected to have the possibility of treating garbage leachate.

• Korean Chemical Engineering Research
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• v.55 no.1
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• pp.68-73
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• 2017

The removal of particulate matter ranging from $0.01{\mu}m{\sim}10{\mu}m$ can be performed by using membrane filters composed of fibers. Electrospinning techniques offer the production of very thin fibers with a uniform fiber diameter over conventional techniques including template synthesis, melt-blown, phase separation, etc. Air filtration will be improved with electrospun membranes due to the open pore structures, high porosity, and large surface area of the membranes. In the present study, filtration efficiency increased with pore size decrease and fiber density increase induced by carbon nanotube and the increased CA (cellulose acetate) concentration during electrospinning process.

• Tribology and Lubricants
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• v.12 no.3
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• pp.39-47
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• 1996

The magnetic fibrous polymeric oil filter elements for industrial lub-systems were obtained by pneumoextrusion processing prepared from thermoplastic pqlymer (polyamide) containing a magnetic particulate filler (Ba ferrite), and treated subsequently in a magnetic fields. Using the standard laboratory oil filtration test rig, metallic particle quantifier and image analyser system, the dependence of filtration charateristics of the magnetic filter media on the parameters of porosity and magnetic properties was investigated. The pressure drops and efficiencies of lubricating filter elements were measured on the packing density and magnetised filler content of filter element. Also, the industrial lub-systems such as lubricant filters for gear test rig and electric discharge processing machine were used for testing the flitrational characteristics of tl, c magnetised filter elements. The magnetic fibrous polymeric filter material was shown to possess a highly filtration efficiency in filtering the fine ferrous particles with increasing the magnetic force of filter element. Therefore, it is expected that the magnetic fibrous polymeric filter material should be used for effective oil filrers on the industrial lub-systems.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.919-929
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• 2009

2008, Seoulmetro transports an average of 3,952,000 passengers every day with a 0.8% increase of the daily ridership compared to last year.(Korean Economics '09.01.21) Seoul subway systems ridden by a considerable number of Seoul citizens place their top priority on swiftness, safety and clean underground air quality so as to meet the customer satisfaction. One of the most important problems is to eliminate minute dust(PM10) among the pollutants such as the gas attributable to air pollution and floating particulate matter defined by the ordinance of the Ministry of Environment. Seoulmetro install and operate many kinds of air filtration facilities, however we've launched a research on "Standardization Plan on Underground Air Filtration Facility" for the installation and improvement of optimum standardized air filtration system. As a preliminary study, we're going to consider ventilation system and air filter to supply filtered metropolitan outdoor air aimed at ensuring clean underground environment.

• Clean Technology
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• v.26 no.1
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• pp.22-29
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• 2020

Recently, as the fine dust is increased and the emission regulations of diesel engines have been tightened, interest in diesel soot filtration devices has rapidly increased. There is specifically a demand for the technological development of higher diesel exhaust gas after-treatment device efficiency. As part of this, many studies were conducted to increase exhaust gas treatment efficiency by improving the flow uniformity of the exhaust gas in the diesel particulate filter (DPF) and reducing the pressure drop between the inlet and the outlet of DPF. In this study, the effects of pressure drop by the flow rate and temperature of exhaust gas, DPF I/O ratio, Ash, and PM amount in diesel reduction device were simulated via a 12" diameter DPF and diesel oxidation catalyst (DOC) using ANSYS Fluent. As the flow rate and temperature decreased, the pressure drop decreased, whereas the PM amount affected the pressure drop more than the ash amount and the pressure drop was lower in anisotropic DPF than isotropic DPF. In the case of DPF flow uniformity, it was constant regardless of the various variables of DPF. In ESC and ETC conditions, the filtration efficiency for PM was similar regardless of anisotropic and isotropic DPF, but the filtration efficiency for PN (particle number) was higher in anisotropic DPF than isotropic DPF.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.2
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• pp.161-167
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• 2008

Using an experimental method named filtration-permeation, the influence of sedimentation during filtration was studied for the suspensions composed of particles and that of flocs. The average specific cake resistances measured by filtration do not give accurate values because of the sedimentations during filtration, but the permeation data give quite accurate values. The prolonged permeation rates for the cake formed from particulate suspension do not change, but that rate from the floc filtration changes by the sweeping of flocculant. It is proposed that the cake compressibility can be measured with one set of filtration-permeation experiment by step increase of pressure during permeation period. The another experimental method which can shorten experimental time for floc filtration using filtrationpermeation is also proposed.

• Journal of Power System Engineering
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• v.19 no.1
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• pp.13-18
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• 2015

Over the past years, many research works have been carried out to investigate the factors which govern the performance of diesel engines. The air pollutant emissions from the diesel engines are still significant concerns environmentally in many countries. In the present study, a novel smoke filtration system of diesel engine is proposed. This novel system is composed of filtering elements and vacuum pump driven by exhaust gases emitted from engine cylinders for capturing smoke. In order to verify the excellency of the novel filtration system, the differential pressure across the filtration system is investigated experimentally comparing with other systems which are used commercially in diesel vehicles. As a result it is founded that the differential pressure of the novel system is the smallest among them.

• Land and Housing Review
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• v.10 no.3
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• pp.1-7
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• 2019

Indoor particulate matter(PM) is a carcinogen and needs to be removed and managed. It is generally reduced and removed through ventilation and filtration. Owing to the recent occurrence of high-concentration fine dust and yellow dust in the atmosphere, however, it is difficult to expect the purification of indoor air through the simple introduction of the outside air. For residential buildings, in particular, they are highly dependent on natural ventilation but the lack of natural ventilation is worsening because concerns over the inflow of external pollutants are increasing. Therefore, this study designed and manufactured a window ventilation system that does not require a duct to improve the maintenance and management problems of general ventilation system, and constructed indoor PM concentration change data through performance evaluation.

• Journal of Power System Engineering
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• v.15 no.6
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• pp.16-21
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• 2011

Over the past years, many research works have been carried out to investigate the factors which govern the performance of diesel engine. The air pollutant emission from the diesel engine is still a significant environmental concern in many countries. In the present study, new system of smoke filtration of diesel engine is proposed. This new system is using vacuum equipment and filter for capture smoke. To verification new system experiments are performed at diesel vehicle and engine dynamometer. As a result it is founded that smoke is decreased of 67% at vehicle test and decrease of 45.2% at full load condition of engine dynamometer test.

• Proceedings of the SAREK Conference
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• 2006.06a
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• pp.442-447
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• 2006

In semiconductor manufacturing clean rooms, it becomes important to remove airborne molecular contaminants as well as particulate contaminant in outdoor air introduced into clean rooms. One suitable control technique for these chemical contaminants is air washing by water in an outdoor air handling unit. In order to enhance the removal efficiency of chemical contaminants the effect of adding a heating and humidifying process before an air washer was examined.