• Journal of Korean Society on Water Environment
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• v.37 no.5
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• pp.398-404
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• 2021

The use of water purifiers has been increasing every year due to increased drinking water safety concerns raised by the water pollution accidents occasionally reported. Currently, more than 10 million water purifiers have been distributed in Korea, and the estimation of the purifier sales reaches two million units per year. As a result, the number of used water purifier filters that must be replaced on a regular basis has gradually increased. However, regardless of the considerations for the capacity of used filters remaining, water purifier filters were replaced and collected at regular intervals. The high cost of disposal of the used filters by landfill or incineration were required. Thus, in this study, the current status and trends of recycling technologies for used water purifier filters were reviewed. It is noted that there was insufficient statistical data to understand the current status of the difference between the number of used water filters discarded and the number of those recycled. Most studies on the recycling of old water purifier filters have concentrated on pretreatment and cleaning methods for sediment filters and membrane filters, with the goal of extending the lifespan of used filters. Further, the study suggested future study directions on the recycling of used water purifier filters, which could be useful information on establishing environmental policy to promote the recycling of used filters.

• Proceedings of the Membrane Society of Korea Conference
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• 1997.06a
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• pp.207-231
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• 1997

The use household water purifier is continuously increasing due to the distrust of the piped, rap water, which may be caused by the deterioration of water quality and water supply facilities in Korea. The water purifier distributing in the domestic market is the membrane type that composes of membrane as a basic filter, sediment filter as a prefilter and activated carbon filter instead of one purifying water system. The membrane type using as a water cleaning system is mainly the method of micro filtration(NIF) as well as ultra filtration(UF) and reverse osmosis(RO). The types of MF and UF are using to remove suspended solids and virus, and RO is using to remove ionic compound in chemical organic compounds. At the beginning the household water purifier was imported as end-product or assembled by only importing module from small businesses in Korea. Therefore, people was hard to confide in the product quality because the sales policy and management of water purifier by small business were not effectively organized. However, the defects of water purifier having up to now ate improving by the efforts of special branches of water purifier and large enterprises, and new great products are developing and producing. To develop the best quality product of water purifier in Korea, it should be considered seasonal water characteristrics rather than any other condition. For example, the water purifier can be affected by the water temperature change, increase of suspended solids in the rainy season and inflow of raw water having concentration in a dry season. The subject we have to investigate in the future is to develop the water purifying system adaptable in Korea which can treat the water quality using close analyses of local and seasonal water characteristics.

• Journal of environmental and Sanitary engineering
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• v.18 no.1
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• pp.1-7
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• 2003

There are lots of waterborne diseases which are caused by pathogenic microorganisms disseminated in contaminated environment. The purpose of this study is to investigate the status of water qualify and in order to investigate the sanitary condition of water purifier in northern part of Gyeonggi-do. We analyzed pathogenic microorganisms and 44 items of drinking water criteria from April to July in 2002. The results were as follows. 1. In 774 samples of water purifier, Pathogenic bacteria(salmonella, E coli O-157, O-26, O-111, shigella, pseudomonas etc.) were not isolated and total coliforms not detected. 2. About 76.5% of the water with purifier are found to be appropriated to the drinking water quality criteria. but 182 samples(23.5%) were without limits of drinking water criteria. 3. In the microbiological examination, 774 samples of purified water showed that 169 samples(21.9%) exceed the range of recommended limits(100 $CFU/m{\ell}$) to the total viable bacterial counts by pour plate method.

• Journal of Korean Society of Water and Wastewater
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• v.21 no.5
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• pp.631-639
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• 2007

This study investigated the construction and operation status of sewer pipes and water-purifier tanks near densely populated areas like large apartment complexes, in order to find out cause for offensive orders. The study results revealed that the main cause arose from the water-purifier tank and public sewer pipes near ordinary residential areas. First, in case of independent water-purifier tanks, the air is forced into the rotten part of large tanks nearby which should be operated in an anaerobic state, so that the tank changes into an aerobic state, or dirty water, which is returned during the sludge return process, falls on the top of the rotten tank, preventing scum from forming within the tank. Such problems cause incompletely purified water in the purifier tank to be discharged, which in turn results in filthy water. Second, in case of public sewer pipes, deteriorated or aging pipes, or the mixture of rain water and dirty water by mixing up combined and separated sewers system can cause foul odors in residential areas. Therefore, offensive odors in residential areas can be radically reduced through the appropriate construction and management of facilities including water-purifier tanks. As well, if more separate sewers are installed as part of an improvement project for public sewer pipes, complaints about foul smell can be minimized.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.10
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• pp.1251-1256
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• 2014

The use of lubrication oil is of many purposes and one among them is to drive the engine mounted on a ship. Hence the supply of clean lubrication oil is important. And an oil purifier is one of key components in marine diesel engines. At present, the element type full-flow oil filter has been widely used for cleaning the engine oil. The self-driven centrifugal oil purifier is a device which is used to remove the impurities in lubrication oil using a jet flow. The flow characteristics and the physical behaviors of particles in this self-driven oil purifier were investigated numerically and the filtration efficiencies were evaluated. For calculations, a Computational Fluid Dynamics method is used and the Shear Stress Transport turbulence model has been adopted. The Multi Frames of Reference method is used to consider the rotating effect of the flows. The influence of centrifugal forcehas been numerically investigatedto improve filtration efficiency of tiny particles. As a result of this research, it was found that the particle filtration efficiency using the only center axis rotating and outer wall rotating system are higher than that of the fully rotating system in the self-driven oil purifier.

• Journal of the Korean Society of Visualization
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• v.20 no.2
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• pp.21-27
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• 2022

Air purifiers can be placed where the air cleaning is required, making it easy to manage indoor air quality. The position of the air purifier affects the indoor airflow pattern, resulting in different air cleaning efficiency. Many efforts and strategies have been examined through numerical simulations and experiments to find the proper location of the air purifier, but problems still remain due to the various geometrical indoor spaces and arrangements. Herein, we develop an artificial intelligence model to predict the performance of an air purifier depending on the installation location. To obtain the training data, numerical simulations were performed on the different locations of the air purifiers and airflow patterns. The trained artificial intelligence model predicted the air exchange performance depending on the installation location of the air purifier with a prediction accuracy of 92%.

• Fire Science and Engineering
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• v.26 no.3
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• pp.35-39
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• 2012

This paper analyzes the combustion diffusion pattern when a water purifier is artificially ignited outside and inside in order to provide data to examine the cause of fire of a water purifier damaged by fire. The analysis result of the combustion diffusion pattern of a water purifier shows that the combustion diffused at a higher speed when it was ignited inside the purifier than when ignited outside. It took approximately 360 seconds for the water purifier to be half-burned when ignited on the outside, and approximately 180 seconds when ignited from inside. That is, it is thought that the internal combustion speed is higher because the internal ignition causes the generated heat to be accumulated and radiated instantly. It was observed that the water purifier damaged by fire caused by external ignition showed a uniform carbonization pattern and the carbide burned down at the bottom were gradually deposited. The water purifier damaged by internal ignition showed a relatively clear boundary of carbonized surface, which formed a V-pattern. The difference in the combustion patterns presents an objective base from which to determine where the fire started. By the time the purifier was half-burned by fire, the built-in fuse had not melted and the power supply protection device did not operate. In addition, as was found in the case of the fuse damaged by a general fire, carbonization occurred at the metal holder, and it is thought that this fact may be used as a basis from which to determine the cause of a fire.

• Journal of the Korean Society of Safety
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• v.28 no.2
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• pp.21-25
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• 2013

The purpose of this study is to provide basic data for the safety assessment of a water purifier when water leaks due to inappropriate maintenance and the examination of the cause of accidents related to the leak. Due to its inspection and management by non-specialists, if a leak occurs in a water purifier with the water level controller being inclined, it may result in the failure of the compressor, power supply line, PCB, etc. The analysis of the thermal diffusion pattern of water purifier compressors using a thermal image camera shows that its maximum temperature was approximately $80^{\circ}C$. In addition, its operating current was a maximum of 13 A and the system's operating current was approximately 1.7 A after the compressor was charged. It was found that the housing type power cable cover of the compressor had the effect of preventing electric shock but has poor flame resistance. Furthermore, the performance of the overload protector, PTC relays, etc., was excellent but they have potential for problems as metallic terminals were exposed, resulting in the potential of a safety related accident. The terminals and their surface damaged by the tracking showed a trace of carbonization and the resistance between terminals was measured to be approximately $8{\Omega}$. In addition, while the tracking was proceeding, the fuse and circuit breaker installed for system protection did not operate.

• Journal of environmental and Sanitary engineering
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• v.5 no.1
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• pp.65-72
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• 1990

To study on the water quality of domestic purifier, twenty four samples of clean water by purifier and the raw water(tap water) were tested for biological and physico-chemical examination and were checked for style of purification and the period elapsed after changing of purification medium. The results were as follows; Biological and physico-chemical findings of raw water were not exceeded standard values. Average number of general bacteria,2.coli and pH in clean water were significantly higher than that of raw water(respectively, p<0.01), but mean contents of turbidity, chloride, nitrate and iron in clean water were significantly lower than that of raw water(respectively, p<0.01). In general count of bacteria and E.coli, a half of the clean water of ceramic filter and roverse osmosis style were exceeded standard values for drinking water. All of the pH of the ion exchange style clean water were exceeded standard values. But other findings were within standard values. In average bacterial counts and physico-chemical findings of clean water by purification style of purifier, clean water of ion exchange style purifier were lowest number of general bacteria and not detected in 2. coli. But other items were highest. The longer period elapsed after changing of purification medium were the higher contents of biological and physico-chemical findings of clean water.

• Particle and aerosol research
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• v.17 no.4
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• pp.107-114
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• 2021

In this study, the effect of the air purifier located in the living room on the reduction of PM_2.5 concentration in the living room and bedroom was investigated. Measurements were carried out in real-life for about 2 weeks in a Korean apartment building where a 3-person household had lived and the exclusive private area was 84.9 m². When the air purifier in the living room was operating, the change in PM_2.5 concentration was measured when the door to the bedroom connected to the living room was opened and closed. In the case of living with the bedroom door open, the average PM_2.5 concentrations in the living room and bedroom were almost the same. When living with the bedroom door closed, the average PM_2.5 in the living room was higher than in the bedroom. The ventilation and cooking effects in the living room mainly affected the PM_2.5 concentration in the living room. Only one air purifier in the living room was able to keep the PM_2.5 concentration in the living room and bedroom low.