• Journal of Korean Society of Water and Wastewater
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• v.34 no.5
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• pp.357-371
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• 2020

Microplastics have become a rising issue in due to its detection in oceans, rivers, and tap water. Although a large number of studies have been conducted on the detection and quantification in various water bodies, the number of research conducted on the removal and treatment of microplastics are still comparatively low. In the current research, the inflow and removal of microplastics were investigated for various drinking water treatment plants around the world. Addition to the investigation of filed research, a survey was also conducted on the current research trend on microplastic removal for different treatment processes in the drinking water treatment plants. This includes the researches conducted on coagulation/flocculation, sedimentation, dissolved air flotation, sand filtration and disinfection processes. The survey indicated mechanisms of microplastic removal in each process followed by the removal characteristics under various conditions. Limitations of current researches were also mentioned, regarding the gap between the laboratory experimental conditions and field conditions of drinking water treatment plants. We hope that the current review will aid in the understanding of current research needs in the field of microplastic removal in drinking water treatment.

• Environmental Engineering Research
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• v.21 no.4
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• pp.319-332
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• 2016

Micropollutants are often discharged to surface waters through untreated wastewater from sewage treatment plants and wastewater treatment plants. The presence of micropollutants in surface waters is a serious concern because surface water is usually provided to water treatment plants (WTP) to produce drinking water. Many micropollutants can withstand conventional WTP systems and stay in tap water. In particular, pharmaceuticals and endocrine disruptors are examples of micropollutants that are detected at the drinking water, ppb, or even ppb level. A variety of techniques and processes, especially advanced oxidation processes, have been applied to remove micropollutants from water to control drinking water contamination. This paper reviews recent researches on the occurrence and removal of micropollutants in the aquatic environments and during water treatment processes.

• Membrane Journal
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• v.13 no.1
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• pp.1-8
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• 2003

Membrane filtration systems have been focusing and increasing rapidly in the filed of drinking water treatment because of several reasons. We describe briefly the present state of membrane filtration processes for drinking water treatment in Japan: including background, objectives, membrane suppliers, and some cases of actual plants.

• Journal of Korean Society on Water Environment
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• v.26 no.3
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• pp.446-453
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• 2010

This study was investigated nine nitrosamines in small tributary rivers, sewage treatment plants (STPs) and drinking water treatment plants. They are N-nitrosodimethylamine (NDMA), N-nitrosomethylethylamine (NMEA), N-nitrosodiethylamine (NDEA), N-nitrosopyrrolidine (NPYR), N-nitrosodi-n-propylamine (NDPA), N-nitrosomorpholine (NMOR), N-nitrosopiperidine (NPIP), N-nitrosodi-n-butylamine (NDBA) and N-nitrosodiphenylamine (NDPHA). The nine nitrosamines were analyzed by gas chromatography mass spectrometry (GC/MS) using solid phase extraction (SPE) with a coconut charcoal cartridge. Among the nine nitrosamines, NDMA, NMEA, NDEA, NDPA NDBA and NDPHA were detected in small tributary rivers and sewage tretment plants. In small tributary rivers, NDMA, NMEA, NDEA, NDPA, NDBA and NDPHA were obtained as ND~16.4 ng/L, ND~17.7 ng/L, ND~102.4 ng/L, ND~455.4 ng/L, ND~330.1 ng/L and ND~161.0 ng/L, respectively. Also NDMA, NMEA, NDEA, NDPA and NDBA were investigated ND~821.4 ng/L, 22.5~55.4 ng/L, 53.2~588.5 ng/L, ND~56.6 ng/L and ND~527.9 ng/L in STPs, respectively. In drinking water treatment plants, NMEA and NDEA concentration were increased to as high as 38.8 ng/L after ozonation process. However nitrosamines were decreased subsequent biological activated carbon (BAC) treatment process. It was supposed that nitrosamines were formed by $O_3$ oxidation and were removed by biodegradation of BAC.

• Journal of Korean Society of Water and Wastewater
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• v.31 no.6
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• pp.491-499
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• 2017

The chemical structures of perfluorinated compounds(PFCs) have unique properties such as thermal and chemical stability that make them useful components in a wide variety of consumer and industrial products. Two of these PFCs, perfluorooctane sulfonate(PFOS) and perfluorooctanoic acid(PFOA), have received attention and were the most commonly detected. In this study it was analyzed the concentrations of 8 PFCs in samples were collected from drinking water treatment plants for 5 years(2012-2016). PFOS and PFOA were also high concentration and frequency. The mean concentrations of PFOA and PFOS were detected $0.0026-0.0069{\mu}g/L$ and $0.0009-0.0024{\mu}g/L$ in samples from drinking water treatment plants. These were relatively lower or similar compared to PFOS concentrations in Osaka(Japan). In general, these levels are below health-based values set by international authoritative bodies for drinking water. These results will be serve as the first monitoring data for PFCs in drinking water and be useful for characterizing the concentration distribution and management of PFCs in future studies.

• Journal of environmental and Sanitary engineering
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• v.7 no.2
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• pp.83-94
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• 1992

Recently water demand is increasing as the industry prospers. The increase of water demand is followed by the increase of wastewater discharge which pollutes rivers and ground water extensively. These rivers, reservoirs and ground water are sources for drinking water and their contamination affects the quality of water supply and other potable water. In Korea there are 776 water treatment plants which supply drinking water from main rivers or reservoirs. Rivers are the biggest water source for drinking water is being contaminated, the innovation of treatment process is needed. The construction and operation of water supply facilities is under the control of the Ministry of Construction and the water supply offices of cities and provinces. However, drinking water quality is under the control of the bureau of sanitation in the Ministry of Health and Social Affairs. There are 33 items in drinking water quality standards of Korea. Trihalomethanes, Selenium, Diazinone and other three of pesticides have been included lately, The Ministry of Health and Social Affairs is planning to enhance. the level of $VOC_S$(Vola-tile Organic Compounds) standard. Drinking water quality standard is the goal to protect the quality of supply water and ground water. In order to protect the source water from domestic or industrial water, technological improvement and adequate investment should be urgently made. The ultimate goal of drinking water quality is safety and health of consumers. The more stringent the standard are, the better the water quality will be. As the drinking water quality standards become more stringent this year, various and positive solutions by the authorities concerned must be prepared.

• Journal of Korean Society on Water Environment
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• v.23 no.1
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• pp.1-11
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• 2007

The low nutrient environment in drinking water treatment plants and distribution systems cannot to be a good environment for bacterial growth. However, biofilms can be frequently found submerged surface in treatment plants and distribution system. Biofilms in distribution system are harmful, in that they can release organisms, and may cause problems in taste and odor of water. Control of these Biofilms is difficult, and disinfection alone is usually ineffective. Biofilms will not be eliminated from distribution systems by any contemporary technology available now or in the future. Therefore reduction of organic matter, improved disinfection, or a combination of these methods can be useful in controlling distribution system biofilms.

• Journal of Environmental Health Sciences
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• v.39 no.5
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• pp.391-407
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• 2013

Micropollutants emerge in surface water through untreated discharge from sewage and wastewater treatment plants (STPs and WWTPs). Most micropollutants resist the conventional systems in place at water treatment plants (WTPs) and survive the production of tap water. In particular, pharmaceuticals and endocrine disruptors (ECDs) are micropollutants frequently detected in drinking water. In this review, we summarized the distribution of micropollutants at WTPs and also scrutinized the effectiveness and mechanisms for their removal at each stage of drinking water production. Micropollutants demonstrated clear concentrations in the final effluents of WTPs. Although chronic exposure to micropollutants in drinking water has unclear adverse effects on humans, peer reviews have argued that continuous accumulation in water environments and inappropriate removal at WTPs has the potential to eventually affect human health. Among the available removal mechanisms for micropollutants at WTPs, coagulation alone is unlikely to eliminate the pollutants, but ionized compounds can be adsorbed to natural particles (e.g. clay and colloidal particles) and metal salts in coagulants. Hydrophobicities of micropollutants are a critical factor in adsorption removal using activated carbon. Disinfection can reduce contaminants through oxidation by disinfectants (e.g. ozone, chlorine and ultraviolet light), but unidentified toxic byproducts may result from such treatments. Overall, the persistence of micropollutants in a treatment system is based on the physico-chemical properties of chemicals and the operating conditions of the processes involved. Therefore, monitoring of WTPs and effective elimination process studies for pharmaceuticals and ECDs are required to control micropollutant contamination of drinking water.

• Journal of Korean Society on Water Environment
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• v.21 no.5
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• pp.431-441
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• 2005

The study was carried out to improve and regulate the drinking water quality standard and drinking water quality monitoring substances. For the reliability and safety of finished water, It has been monitored for trace organic and inorganic compounds of 333 in finished water of water treatment plants during 1989 to 2003. As a result of monitoring, 51 compounds were detected from 333 compounds, and it has been regulated the drinking water quality standard of 26 substances and 20 mitoring substance. Improvement and regulation method of the drinking water quality standard was performed by comparing and analyzing with detection concentration, detection frequency, risk assessment and foreign drinking water quality standard.

• Journal of Korean Society on Water Environment
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• v.20 no.3
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• pp.245-250
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• 2004

This study investigated the micropollutants present in raw water supplied for the several drinking water treatment plants in Seoul. The target sample waters were collected from the several sites, such as Jayang (JY), Kuui (KI), Paldang (PD) and Kangbuk (KB) at the Han-River stream. The analytical method used in this study enable us to detect about 300 kinds of chemicals commonly found in surface water at ppt level by GC-ion trap MS. In this study, the consideration on the analytic results focused on the four hazardous organics, such as benzenes, phenols, phthalates and pesticides. The numbers of each detected micropollutant were 1~8 kinds for benzenes, 1~7 kinds for phenols, 5~7 kinds for phthalates and 1~9 kinds for pesticides. For the pesticides, the higher concentration was detected in the water samples collected from PD and KB adjacent to the farming area, and at June and July, which is the busy farming season. The total concentrations of each micropollutants detected at all the sites were significantly lower than those of drinking water regulation in Korea as well as other advanced countries. However, the frequently detected micropollutants requires the steady and precise monitoring for the effective management of drinking water source.