• Membrane and Water Treatment
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• 제6권1호
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• pp.43-52
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• 2015

A small-scale electro-dialysis system was constructed for domestic use. It is composed of six compartments in which five special polystyrene ionic membranes are housed. A series of experiments on the transport of sodium and chloride ions through polystyrene membranes was performed and the effects of electric current and voltage on the pH of water were investigated. This electrodialyser could reduce the NaCl content to an acceptable level (5307 mg/L) when water containing 9945 mg/L of sodium chloride is fed to the electrodialyser. The reduction was by the action of direct current 60 mA/100 mA when a 15 V / 20 V potential is maintained across the membrane. The results showed that the pH of the treated water attained a value in the range of 7-8, with the chloride concentration of 5307 mg/L when the voltage was in the range of 20 volts. This was achieved when two of the small-scale electro-dialysers were placed in series and the solutions from the respective compartments were mixed. This is considered useful because this complies to the requirement of drinking water standard both in terms of chloride and pH. Therefore, this type electrodialyserhas the potential for domestic uses in isolated houses where potable water supply is not available.

• 상하수도학회지
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• 제18권1호
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• pp.49-58
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• 2004

This study is to analyze the affecting factors to the peak factor in the drinking water supply Facilities. The peak factor is a very important element to determine the capacity of the water supply facllities. Several factors such as Population served, average day water demand, ratio of domestic water use, ratio of affairs & business water use and water use per capital per day were selected as the affecting factors in this study. In this study, peak factor characteristics for Korean facilities were compared with those for Japanese ones. As a result, non-exceedance probability was suggested as the designing method for the peak factor. Also, the 50% non-exceedance probability values and the 90% values based on the 1998-1999 data were suggested in this study.

• 한국환경보건학회지
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• 제44권3호
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• pp.244-249
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• 2018

Objectives: The purpose of this study was the investigation of bromide and bromate in drinking water of water supply plants, mineral springs and small water supply system located in northern area of Gyeonggi province. Methods: Analytical method was based on EPA 326.0 to use Postcolumn reaction (PCR). The instrument was 887 professional UV/VIS detector IC manufactured in Metrohm. Results: Bromate was detected at $0.5{\sim}2.4{\mu}g/L$ in tap water from 5 water supply plants. These plants were used as disinfection method for sodium hypochlorite and on-site chlorine that causes generate bromate as a by products even if not used ozone. Conclusions: The bromate was detected up to $2.5{\mu}g/Lin$ drinking water in northern Gyeonggi area that showed within $10{\mu}g/L$ for standard of tap water. However, the continuous monitoring of bromate is necessary in drinking water.

• 한국환경보건학회:학술대회논문집
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• 한국환경보건학회 2005년도 국제학술대회
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• pp.263-272
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• 2005

Chlorine disinfection has been used in drinking water supply to disinfect the water-borne microbial disease which may cause to serious human disease. it is still the least costly, relatively easy to use, Chlorination is the primary means to disinfect portable water supplies and control bacterial growth in the distribution system. However, chlorine reacts with natural organic matter(NOM), that presents in nearly all water sources, and then produces disinfection by-products(DBPs), that have adverse health effects. Although the existent DBPs have been reported in drinking water supplies, it is not feasible to predict the levels of the various DBPs due to the complex chemistry reaction involved. 1. The objectives of this study is to investigate seasonal variation difference concentration of DBPs in the plant to tap water. The average concentration of THMs was 20.04 ${\mu}g/{\ell}$ , HAAs 8-15 ${\mu}g/{\ell}$ , HANs 2-4.5 ${\mu}g/{\ell}$ respectively. 2. Distant variation of DBPs furmation by the distance is that THMs concentration increased by 17% at 2km point from the plant and by 28% at 7km and HAAs, HANs also increase each by 16%, 32% at 2 km from the plant and 35%, 56% at 7 km. DBPs increase in water supply pipe continually, 3. The seasonal occurrence of BBPs is that in May and August DBPs concentration is very higher than in march, in May DBPs concentration is highest. The temperature is main factor of DBPs formation, precursor also. 4. Precursor which was accumulated for winter flowed into the raw water by flooding in spring and summer and produced DBPs. 5. Therefore for the supply of secure drinking water, it is required to protect precursor of flowing into raw water and to add to BCAA and DBAA to drinking water standards.

• 한국환경보건학회지
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• 제17권2호
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• pp.27-34
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• 1991

This study was carried out to investigate the use habit of drinking water. The survey data were collected from 1,282 of students and 175 of officers from September 1990 to June 1991 in Pusan city and the South of Kyung sang-do. The use rate of tap water among respondents was 33.5%, and the reasons that the others avoid using tap water were having the risk of heavy metals contamination and unsanitary. The 80% of respondents have drunk spring water or bottled water within two or three years. The keeping method of them were 53% in the refrigerator, and 33% in the indoor. The use rate of water vessels what were equipped in mineral springs was 85%. It's advisable that the picking of mineral water be cautious within two or three days after rain. The holding rate of water purifier in respondents was about 20%, and it was purchased within one or two years and the reliance degree of that in users was below 50%.

• 대한환경공학회지
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• 제39권1호
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• pp.1-8
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• 2017

식수부족문제는 지표수와 지하수의 오염, 수처리의 어려움, 기반시설의 부재로 인해 많은 개발도상국에서 주로 발생하고 있다. 이에 빗물을 모아 식수로 이용하는 빗물식수화시설(RFD)이 매우 효과적인 대안으로 떠오르고 있으며, 전 세계적으로 빗물식수화시설 사업이 진행되고 있다. 대부분의 빗물식수화시설은 지역주민이 사업 종료 후부터 스스로 시설을 운영하도록 하기 때문에 빗물식수화시설 사업에 대한 지역주민의 인식이 매우 중요하다. 따라서 본 연구에서는 베트남에서 빗물식수화시설을 사용하는 총 209명의 현지 지역주민을 대상으로 설문조사와 면담을 실시하여 지역주민의 인식을 조사하였다. 지역주민들은 빗물식수화시설 사업의 효과성에 긍정적인 인식을 가지고 있으며(41.9%), 빗물식수화시설 사업에 참여의향이 있는 것으로 나타났다(58.9%). 지역주민이 빗물식수화시설 사업에서 가장 기대하는 세가지 요소는 '안전한 식수의 공급', '마을공동체의 활성화', '빗물식수화시설의 확산'순으로 나타나 빗물식수화시설 사업에의 참여를 통해 안전한 식수를 공급받는 것을 가장 기대하는 것으로 파악되었다. 빗물식수화시설 사업에서 가장 우려하는 세가지 요소로는 '빗물의 수질', '빗물식수화시설의 설치 기술', '지역주민의 참여도'순으로 나타났으며, 특히 빗물식수화시설 사업의 종료 후의 빗물 수질과 시설의 유지관리를 우려하는 것으로 파악되었다. 빗물식수화시설 사업의 종료 후에도 지역주민이 성공적으로 빗물식수화시설을 운영하기 위해서는 빗물식수화시설의 수질을 용이하게 측정할 수 있는 간편한 수질 측정 도구의 개발과 지역주민 스스로가 빗물식수화시설에 관심을 가지고 유지관리를 할 수 있도록 빗물식수화시설에 대한 정기적인 교육을 진행하는 것이 필요할 것이다.

• 한국환경보건학회지
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• 제45권6호
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• pp.561-568
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• 2019

Objectives: The most commonly detected heavy metals in rocks and soils, including Pb, Cd, Cu, Fe, Mn and As, are representative pollutants discharged from abandoned mines and have been listed as potential sources of contamination in drinking water. This study focused on increasing the removal efficiency of heavy metals from drinking water resources by surface modification of natural adsorbents to reduce potential health risks. Methods: Iron oxide coating and graft polymerization with zeolites and talc was conducted for bipolar surface modification to increase the combining capacity of heavy metals for their removal from water. The removal efficiency of heavy metals was measured before and after the surface modification. Results: The removal efficiency of Pb, Cu, and Cd by surface modified zeolite showed 100, 92, and 61.5%, respectively, increases compared to 64, 64, and 38% for non-modified zeolite. This implies that bipolar surface modified natural adsorbents have a good potential use in heavy metal removal. The more interesting finding is the removal increase for As, which has both cation and anion characteristics showing 27% removal efficiency where as non-modified zeolite showed only 2% removal. Conclusions: Zeolite is one of the most widely used adsorptive materials in water treatment processes and bipolar surface modification of zeolite increases its applicability in the removal of heavy metals, especially As.

• Membrane and Water Treatment
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• 제2권4호
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• pp.251-266
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• 2011

This work deals with the use of High Resolution Scanning Electron Microscopy (HRSEM) to verify ultrafiltration membrane selectivity at the end of the production line as well as membrane ageing. The first part of this work is focused on new membranes. It is shown that it is better to use sputtering metallization than vacuum deposition, as this latter technique entails thermal damage to the skin layer. Moreover, the impact of the metallization layer on the determination of the membrane pore size is studied and it is observed that no impact of the metallization step can be clearly defined for a metallization layer ranging from 3 to 12 nm. For example, an average pore size of 16.9 nm and a recovery rate of 6.5 % are observed for a 150 kDa cellulose acetate membrane. These results are in agreement with those given by the manufacturer: pore size ranging from 10 to 15 nm and recovery rate ranging from 5 to 10 %. The second part of this work focuses on the study of membrane ageing. A PVDF hollow fibre membrane is studied. It is shown that a 65 % decrease in the permeate flux can be linked to a decrease in the number of pores at the surface of the membrane and a decrease in the recovery rate. In conclusion, a mapping of the pores is performed for several new hollow fibre membranes used to produce drinking water, made of different materials, with different geometries and molecular weight cut-off. These results provide reference data that will help better understand the phenomena of membrane fouling and membrane ageing.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2002년도 Proceedings of International Symposium on Remote Sensing
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• pp.506-506
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• 2002

S. Korean Government has accelerating its efforts to enhance the quality of the drinking water. The Ministry of Environment has declared the law of securing water-pollutant buffering zone to minimize the inflow of the point and nonpoint sources into the drinking water sources. As a first phase of installing nationa-wide water-pollutant buffering zone, approximately 300km buffering zone has been delineated along the South and North Han river, the major drinking water sources for the capital area of S. Korea, which has the population of more than 12 millions. The buffering zone has the width of 1,000 meter for the special protection area, and 500 meter for the remaining area from both ends of the river. The major works have been done in three stages. Firstly, the boundaries lines of the buffering zone was delineated on the digital topographic maps. Secondly, the maps were overlayed with the cadastral maps to identify individual land parcels, the street address of the major pollutant discharging facilities, and all different types of pollutants including livestocks. Thirdly, the field work has been done as a verification. Once the buffering zone was generated, all the information for the buffering gone were created or imported from other government agencies including official land price, details of the major manufacturing facilities discharging considerable amount of pollutants, major motels and resorts, not to mention of restaurants, etc. Also, major livestock houses were located to identify the path of the pollutant inflow to the drinking water source. Further works need to be continued such as purchasing private lands within the buffering zone and change the land use in the efforts to decrease the pollutant amount and to provide more environmentally friendly space. Also, high resolution satellite imagery should be utilized in the near future as a cost-effective data source to update all the landuse activities within buffering zone.

• 한국환경과학회지
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• 제7권2호
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• pp.217-222
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• 1998

Organics matters including algae are the major contaminants of Nak-dong river and it's concentration Is more Increasing now. The use of coagulants has been Incresed for the effective treatment of drinking water, and aluminum coagulants have been the most widely used in raw water treatment. However, when inorganic metal coagulant is excessively used for long period, it would result in secondary problems, such as increasing sludge production, enhancing the cost of water treatment process, and increasing concentration of residual metal, especially aluminum. Therefore, recently. in order to reduce the use of metal coagulant and enhance the coagulation effectiveness, several alternative coagulants, such as polymeric Inorganic coagulants and organic polymers, have been used In water treatment plants. The objectives of thins research were (11 to determine optimum dosage concentration and compare the coajuiation efnciency at various pH ranees with alum alone, alum+cationic polymer, and alum+anlonlc polymer, (21 to evaluate the amount of alum reduced by using organic polymer, (31 to maximize removal officiency of organic matter and minimize the concentration of residual aluminum.