• 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.

• Membrane Journal
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• v.27 no.3
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• pp.232-239
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• 2017

In this study, the regeneration investigation for waste reverse osmosis membrane filters which were discarded after use for the household water purifiers has been carried out. Sodium hydroxide, sodium bisulfate, and ethylenediamine tetra acetic acid(EDTA). as the chemical cleaning agents were used. And they were in-situ cleaned with the micro-bubble generator as well. The best result was obtained when both 0.1% EDTA and micro-bubbles were used for 30 min cleaning. Thus, when the performance of the brand new RO membrane and restorated RO membrane were compared, the flux, 19.9%, the recovery ratio 45% were enhanced while the salt rejection was reduced for NaCl 100 mg/L solution, in other words, it has been recovered to the original brand new RO membrane filter. Also the removal of pollutants on membrane surface was confirmed in a naked eye through the scanning electron microscopy. Finally, this research has provided the possibility of the re-use of the waste RO membrane filters of household water purifier which were reclaimed or incinerated after use.

• Environmental and Resource Economics Review
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• v.12 no.4
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• pp.559-577
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• 2003

This paper analyzes household bottled water and water purifier expenditures, taking into account three important characteristics: expenditures may be censored at zero, may be interdependent across expenditure type, and may be endogenously and jointly determined. Censoring, interdependence, and endogeneity of the two expenditures are examined through simultaneous equation bivariate Tobit model. Expenditure function parameters are estimated using a 1997 household survey data collected in Seoul. The study detected interdependence between the two expenditures in the data. Moreover, the coefficient of one expenditure variable is statistically significant in the other expenditure equation. Thus, the overall results show that the simultaneous equation bivariate Tobit model employed here is appropriate for this analysis of the two expenditures. Finally estimated income and household size elasticities of the expenditures are presented.

• Journal of Industrial Technology
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• v.27 no.B
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• pp.3-7
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• 2007

Ultraviolet light(UV-C, wavelength: 200~280nm) is employed profitably for sterilizing drinking water. For most water serving apparatus such as a water purifier, a water cooler and heater, a coffee vending machine and etc., pre-sterilized water may be contaminated secondarily with bacillary inhabitation in a container before serving. In consideration of this problem, a household water tap which is equipped with a sterilization/Purification device in combination with non-contact UV-lamp, was designed to sterilize and purify water at the last outlet just before serving. Hopefully this simple but creative item may be commercialized for household and public use.

• Journal of Environmental Impact Assessment
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• v.26 no.5
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• pp.344-353
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• 2017

Cambodia is a typical country that a very famous tourist destination in South Asian regions, but water has some serious problems. As a public hygiene point of view, water problems in Cambodia can be roughly classified into two categories. A numbers of the report revealed that thermotolerant coliform(TTC) bacteria and arsenic(As) pollution representative species as a representative pollutant for surface water and ground water problems, respectively. In recent years, home water purifier systems for various filter systems including BSF(Bio-Sand Filter), MF and RO have been spread and adopted in rural areas. However, BSF and composite membrane processes are recognized as an undesirable and representative method due to unreliable efficiency, high cost and maintenance issues. In order to develop a small-scale ceramic filter as a home water purifier, the applicability of two types of gravity ceramic filter using clay and red soil in the part of the Northwest was made and compared in this research.

• Membrane Journal
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• v.8 no.4
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• pp.220-227
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• 1998

Recent data from Environmental department show that some out of 2,000 places surveyed are contaminated by nitrate, ammonia, fluoride, chloride and so forth in excess of the environmental standard-including purification plants, water taps, small water supply systems. In this study, some items which exceed drinking water standard were chosen and their concentrations were made varying from around standard level to around detected maximum concentration. After they permeated through the membrane module sold in the domestic market and made for household water-purifier, the most suitable membranes were selected according to individual water quality of various regions. In addition, the bacterial growth after storage for various days and under various temperatures was examined for the purpose of the effect of the time and temperature on bacterial growth.

• Journal of Advanced Marine Engineering and Technology
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• v.37 no.5
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• pp.541-547
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• 2013

It is important to establish water treatment technologies for drinking water because Korea belongs to water-stressed country. Leachate from recent incident of foot-and-mouth disease has become an opportunity to be aware of the need to manage water quality. Water purifiers are adopted to four or five steps of filtration process. Each steps are composed of a sediment filter, a pre-carbon filter, an UF or a RO membrane filter and a post-carbon filter. And additionally a ceramic filter can be used as a final stage. In this study, operational conditions in each steps are examined and characteristics of each filters are investigated. SEM analysis is used for filter surface and shape investigation using 6 commercial samples. Pore sizes of the sediment filter, the UF membrane filter, and the RO membrane filter are 30~47 ${\mu}m$, 0.005~0.5 ${\mu}m$, and 0.025~0.25 ${\mu}m$, respectively. Specific surface areas of activated carbons are ranged from 622 to 1,308 $m^2/g$.

• Membrane Journal
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• v.29 no.2
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• pp.96-104
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• 2019

The purpose of this paper is whether or not the in-situ restoration of the reverse osmosis (RO) membranes which its membrane function is lost is possible. The damaged RO membranes are double coated through the salting-out method by the poly(styrene sulfonic acid) sodium salt as the cationic exchange polymer and the polyethyleneimine as the anionic exchange polymer and also conducted the opposite order of the coating materials. And according to the concentration, time and ionic strength, the flux and rejection are measured for the coated membranes. Then the best coating condition is to apply for the RO membrane module of the household water purifier to know the possibility of the in-situ restoration for the commercial module. When the condition of the PEI 30,000 ppm (IS = 0.1)/PSSA 20,000 ppm (IS = 0.7) is applied, the rejection was enhance from 69% for the damaged module to 86% (90% for the pristine module).