• 한국지하수토양환경학회지:지하수토양환경
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• 제18권1호
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• pp.16-25
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• 2013

The Korean groundwater law regulates 20 groundwater contamination parameters, including 14 specific harmful substances. Expanding the number of groundwater quality standards are needed to cope with recent groundwater quality deterioration due to the use of various chemicals. Chemical ranking and scoring system (CRS) is a scientific tool to sort priority chemicals by considering exposure and toxicity potentials. In this study, we developed a CRS for scoring and ranking of possible groundwater pollutants and screened priority substances to be later considered in the Korean standard expansion. Chemical Ranking Of groundWater pollutaNts (CROWN) incorporates important parameters consisting of exposure potential, human and water ecotoxicity, interests, and certainty. Furthermore, CROWN additionally evaluated existence of other media standards to consider impacts by contamination of other media. The 197 substances that were common to 9 countries were selected first. CROWN evaluated and ranked each chemical, and finally suggested priority substances. Suggested priority substances were classified into two groups according to the groundwater use purposes: drinking and non-drinking. The priority substances were further classified into $1^{st}$ and $2^{nd}$ group priorities. The $1^{st}$ group consists of 75 substances, including the all the Korean groundwater standard parameters. CROWN will be used in selecting groundwater pollutants for possible inclusion in the Korean standard expansion.

• 환경위생공학
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• 제16권3호
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• pp.34-41
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• 2001

It is well known that bioassay on the low organic matters in water have developed from the two methods. One is assimilable organic carbon(AOC) that makes use of the maximum growth biomass of the pure strains for the standard substrates, the other is biodegradable dissolved organic carbon(BDOC) that determines the fraction of dissolved organic carbon(DOC) available for microbial utilization. The purpose of this study was to upgrade the measurement method of BDOC in natural water or drinking water. BBOC was determined by means of the bacterial growth and the DOC decrease at the same time. The origin inoculums were used to the suspended bacteria from Han River water, The initial optimum biomass and incubation time for initial DOC were induced by variation of nutrient repression and inoculums. The time reached to minimum DOC was selected as incubation time. The initial optimum biomass for Han river water was about 1000~5000 CFU/mL, respectively. In a sufficient biomass, suitable incubation time was about 3~5 day. It was indirectly calculated BDOC on maximum growth rate by measuring growth yield of indigenous bacteria. But it was difficult to adapt growth yield coefficient because of irregular bacterial growth. The measured 3 day BDOC was close to BDOC calculated with our proposed experimental equation between DOC and BDOC. It shows that the quantification of BDOC with this experimental equation can be used indirectly.

• Membrane and Water Treatment
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• 제7권4호
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• pp.313-325
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• 2016

South Africa recognises piped water as the main source of safe drinking water supply. Remote areas do not have access to this resource and they rely solely on surface water for survival, which exposes them to waterborne diseases. Interim point of use solutions are not practiced due to their laboriousness and alteration of the taste. Bio-ultra low pressure driven membrane system has been noted to be able to produce stable fluxes after one week of operation; however, there is limited literature on South African waters. This study was conducted on three rivers namely; Umgeni, Umbilo and Tugela. Three laboratory systems were setup to evaluate the performance of the technology in terms of producing stable fluxes and water that is compliant with the WHO 2008 drinking water guideline with regards to turbidity, total coliforms and E.coli. The obtained flux rate trends were similar to those noted in literature where they are referred to as stable fluxes. However, when further comparing the obtained fluxes to the normal dead-end filtration curve, it was noted that both the Umbilo and Tugela Rivers responded similarly to a normal dead-end filtration curve. The Umgeni River was noted to produce flux rates which were higher than those obtainable under normal dead-end. It can be concluded that there was no stabilisation of flux noted. However, feed water with low E.coli and turbidity concentrations enhances the flux rates. The technology was noted to produce water of less than 1 NTU and 100% removal efficiency for E.coli and total coliforms.

• 상하수도학회지
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• 제18권3호
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• pp.366-376
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• 2004

Use of artificial circulation system has become popular in Korean reservoirs to control algal blooms and subsequent color, taste and odor problems in drinking water. It was found that the most of aeration system in Korean reservoirs are under-designed compared to existing installations in US and Australia. This was especially true for larger reservoirs greater than $5{\times}10^7m^3$ in volume since it is common to install the system in the vicinity of intake areas only. Consequently, successful cases of artificial circulation systems operations are limited to few small reservoirs less than $1{\times}10^7m^3$. It is suggested that the design methods need to be developed considering physical characteristics and water quality kinetics inside of reservoirs. Also operation methods of artificial circulation systems need to be established considering the water quality dynamics, stratification and morphological characteristics of reservoirs. Finally, it is suggested to maintain comprehensive and long term monitoring programs to validate the application of artificial circulation system in reservoirs.

• 한국환경보건학회지
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• 제26권4호
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• pp.45-48
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• 2000

Reverse osmosis filtration(RO) system and ultrafiltration(UF) system are principally use for domestic home drinking water treatment systems. The object of this study is to make a comparison between two systems in terms of theirs abilities to remove RNA coilphage QB as an indicator of pathogenic enteroviruses. The virus removal ratio of RO system was 99.999%, which was higher than EPA virus treatment guideline(99.99%). In the course of filtration, removal ratios of sediment filter, pre-carbon filter, reverse osmosis membrane and post-carbon filter were 75.000%, 93.208%, 99.997% and 99.999%, repectively. In case of UF system, virus removal ratio was 99.708%. Removal ratios of sediment filter, pre-carbon filter, post-carbon filter and ultrafiltration membration membrane were 71.038%, 91.530%, 98.283% and 99.708%, respecively, in UF steps. Therefore, RO system is more effective than UF system in virus removal.

• 동서간호학연구지
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• 제3권1호
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• pp.17-26
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• 1998

The purposes of this study were to identify the contents, frequency of use, and the rationales of folk remedies frequently used for first aid at home for stomachache, vomiting, strain, food poisoning, vaginal bleeding, or wounds of snake or dog bite, or bee sting. As the method of the study, data were collected by conducting a questionnaire of 185 persons, who filled it out or who were interviewed from May to August in 1998. The collected data was analyzed by using frequency and the rationales for the contents of the folk remedies were described base on literatures. The results were as follows,. 1. The folk remedies for stomachache in frequency order were 'warming the abdomen', 'rubbing the abdomen with a hand', or 'pricking a finger to bleed', which have the rationals. 2. The folk remedies for vomiting in frequency order are 'drinking water of watery radish' and 'pricking a finger to bleed', which have the rationales. 3. The folk remedies for strain in frequency order are 'soaking the affected area into cold water or applying an ice pack' and 'after soaking jasmine in water, making a dough with flour, and then attaching it on the affected area', which have the rationales, Additionally, although the frequencies are low, 'drinking brewed Achyranthis Radix' and 'applying brewed leaves and stalks of Sambuci Cortex' have the rationales. 4. The folk remedies for food poisoning in frequency order are 'drinking black beans and licorice brewed together' and 'eating mung beans', which have the scientific grounds. 5. The folk remedies for bloody discharge in frequency order are 'drinking brewed lotus root' and 'eating boiled chicken stuffed with root of bell-flower'. However, 'drinking brewed Thujae orientalis Folium' has the rationales. 6. The folk remedy for snake bite wounds that has the scientific grounds is 'sucking blood by a person without hurt in the mouth'. However, quite a lot of people apply alum or soy paste, which has no rationales. 7. The folk remedies for the bee sting in frequency order are 'after removing the sting, applying soy paste or sauce' and 'applying saliva'. No rationales for 'applying saliva' have been found. 8. The folk remedy for the dog bite wound that has the rationales is 'applying juice of leaves or stalks of Xanthii Fructus'. However, 85% of surveyed people use remedies that have no scientific grounds, such as 'applying burnt dog hair mixed with (sesame) oil' and 'applying soy paste or sauce'. Various materials are used in folk remedies for first aid treatment as shown above. Some of the folk remedies have the rationales since their medicinal actions have been found. However, the medicinal actions of the majority have not been found, but only known that they are effective, Especially for the materials except botanical drugs, they are used without knowing the effects since their components and pharmacognosies have not been described in any literature. The results of this research may be used for materials to educate the surveyed people or to consult them. Accordingly, the folk remedies that have the rationales are required to continue to study to find out the effects.

• 한국물환경학회지
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• 제27권2호
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• pp.178-187
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• 2011

National water supply, water resources available, the ratio of water supply to total water resources, and the ratio of water supply to available water resources were investigated to find global seawater desalination plant market for 163 nations. Water resources available per capita from 2007 to 2016, population in water scarcity region from 2011 to 2016, and the ratio of water scarcity population to total population were also analyzed for the countries. Annual percentage increase in total municipal drinking water capital expenditure and Annual percentage increase in total industrial water market were analyzed to predict the amount of water supply by use. 76 countries are suffering from water scarcity and 60 countries among the countries have coastal regions. Forty countries were selected by considering the considerable amount and highly increasing trend of water demand by use. Most countries show increasing trend of industrial water and 82 countries have more than 4% annual increasing rate for domestic water expense from 2008 to 2016 among 163 countries. Among the 76 water scarcity countries 16 countries were finally selected by considering expense prediction by use. Middle-east, east asia, pacific ocean, and west europe regions include most selected countries.

• 적정기술학회지
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• 제6권2호
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• pp.183-189
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• 2020

개발도상국은 빈약한 식수 인프라로 인해 식수공급에 어려움을 겪고 있으며 식수가 공급되지 않는 지역에서는 지하수를 주된 식수원으로 이용하는 경우가 많다. 하지만 지하수의 경우 다양한 오염원에 노출되어 있고 이로 인한 문제가 발생하기도 한다. 특히 해안지역은 그 지리적 특성으로 인해 해수침투에 노출되기 쉽고 해수침투에 노출된 지역의 지하수는 일반적인 경우보다 높은 염도를 가지는 경향이 있다. 만약 염도가 높은 지하수를 지속적으로 마시게 된다면 심장 및 신장질환 등 인체에 다방면으로 치명적인 영향을 끼치는 원인이 될 수 있기에 주의가 필요하다. 본 연구에서는 해수침투가 일어난 지역에서의 탈염을 위한 기술인 CDI(Capacitive Deionization)와 역삼투의 원리를 이용한 RO(Reverse Osmosis)의 적용가능성을 탐색해보고자 하며, 염수 농도에 따른 정수성능 실험을 진행하여 탈염성능을 평가해 보고자 한다. 또한 개발도상국의 일부 지역은 전력이 원활하게 보급되지 않는 경우가 많기에 본 연구에는 정수하는데 실제 사용하는데 필요한 소비전력을 계산하여 평가에 포함하고자 한다. 이를 통해 개발도상국 해수침투지역에 적합한 탈염기술을 제안할 수 있을 것으로 기대한다.

• 상하수도학회지
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• 제33권5호
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• pp.395-404
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• 2019

The point-of-use water dispenser systems are widely used because of convenience in handling and demand for high-quality drinking water. The application has been increased recently in the public places such as department stores, universities and the rest areas in express ways. Improvement of water qualities by the dispenser systems was compared with tap water in this study. The tap water is supplied to the dispenser as the influent of the dispenser system. The twelve dispensers in the public places were used. The five dispensers used reverse osmosis as the main filter and other dispensers used various filters such as ultrafiltration, nanofiltration, and alumina filter. The water quality indicators for sanitation safety, i.e., turbidity and total coliforms, were evaluated. Other water qualities such as pH, residual chlorine, heterotrophic plate count (HPC), and total cell counts were also analyzed. By the point-of-use water dispenser, the turbidity, residual chlorine and pH were decreased and the HPC and total cell counts were increased. The t-test results revealed that the HPC of the tap waters were not significantly different from the treated waters but the total cell counts of the two groups were significantly different. The low pH of the RO filter treatment was also significantly different from the tap waters. This study will contribute to understand the role of the point-of-use water dispenser in improving water quality and to identify key water quality for the proper maintenance of the dispenser systems.

• KIEAE Journal
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• 제15권5호
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• pp.5-12
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• 2015

Purpose: Retention and infiltration of small and frequently-occurring rainfall by LID facilities account for a large proportion of the annual precipitation volume. Based on 4 standard facilities such as Porous Pavement, Infiltration Trench, Cylindrical Infiltration Well, Rectangular Infiltration Well by Seoul Metropolitan Handbook of the Prior Consultation for LID. The total retention volume of each facility was calculated according to the type and size. The Purpose of this study is to find out the quantitative relationship between Percentile Rainfall Event and Design Volume of Infiltration Facilities. Methode: For the estimation of Percentile Rainfall Event, Daily Precipitation of Seoul from 2005 to 2014 was sorted ascending and the distribution of percentile was estimated by PERCENTILE spreadsheet function. The managed Rainfall Depth and Percentile of each facility was calculated at the several sizes. In response to the rainwater charge volume of 5.5mm/hr by the Category "Private large site", the 3 types of facilities were planned for example. The calculated Rainfall Depth and Percentile were 54.4mm and 90% by the use of developed Calculation-Module based on the Spreadsheet program. Result: With this Module the existing Designed Infiltration volume which was introduced from Japan was simply converted to the Percentile-Rainfall-Event used in USA.