• 한국환경농학회지
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• 제28권2호
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• pp.186-193
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• 2009

The removal efficiency of herbicide glyphosate in a drinking water treatment system was investigated. Four major processes of a drinking water treatment system were selected and experiments were performed separately including; treatments by sodium hypochlorite (NaOCl), a sedimentation process by PAC (polyaluminum chloride), ozonation and a GAC (granular activated carbon) treatment. In the sodium hypochlorite experiment, about 50% of the glyphosate was removed by 2 mg/L of hypochlorite and more than 90% was eliminated when 5 mg/L of NaOCl was applied. Also, AMPA, the main metabolite of glyphosate, was treated with hypochlorite. More than 30% of the AMPA was removed by 2 mg/L of hypochlorite and 50% by 5 mg/L. In the PAC experiment, it was determined that more than 60% could be removed. Further experiments were performed and the results indicated that the removed amount was dependent upon the amount of soil and upon the properties of the soil especially that of clay minerals. Ozonation could oxidize glyphosate to its byproducts at about a level of 50%. In contrast, when 1 mg/L of glyphosate was treated with GAC, the amount removed was negligible. The results of this experiment were conclusive. We confirmed that drinking water, which has been contaminated with water polluted with glyphosate can be effectively purified by the application of the drinking water treatment processes currently used.

• 한국물환경학회지
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• 제21권5호
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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.

• Coupled systems mechanics
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• 제8권6호
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• pp.489-500
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• 2019

With drinking water standards becoming more rigorous and increasing demands for additional water quantities, while water resources are becoming more polluted, mathematical models became an important tool to improve water treatment processes performance in the water supply system. Water treatment processes models reflect the knowledge of the processes and they are useful tools for water treatment process optimization, design, operator training for decision making and fundamental research. Unfortunately, in the current practice of drinking-water production and distribution, water treatment processes modeling is not successfully applied. This article presents a review of some existing water treatment processes simulators and the experience of their application and indicating the main weak points of each process. Also, new approaches in the modeling of water treatment are presented and recommendations are given for the work in the future.

• 한국물환경학회지
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• 제38권6호
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• pp.275-281
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• 2022

To maintain water quality after water treatment, monitoring whether the quality of treated tap water quality changes is essential. However, current investigations are insufficient to prevent secondary contamination in drinking water supply systems. This study investigated Gyeonggi's e apartment where a red water problem occurred and monitored the water quality and corrosiveness of the overall water supply system to the apartment from June 2021 to April 2022. In a comparison of drinking water quality after water treatment and the influent of the reservoir, turbidity and heavy metal concentrations were increased and residual chlorine was decreased due to increases in temperature. Correlation analysis and principal component analysis (PCA) indicated that a low level of residual chlorine may cause the abscission of Mn²⁺ and Fe²⁺ through microorganism activation, which also causes a high level of turbidity. The corrosion index (LI) in the influent of the reservoir tank was increased due to Ca²⁺ and temperature. These results indicate that the corrosiveness of drinking water and the deterioration of drinking water quality were mainly increased between the drinking water treatment plant and the reservoir tank's influent. The findings provide clear evidence that it is essential to manage water supply systems and reservoir tanks to prevent the secondary contamination of drinking water.

• Applied Biological Chemistry
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• 제37권6호
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• pp.472-479
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• 1994

상수처리시 토양현탁액과 같은 유기물이 있을 때 산화제, 응집제 및 흡착제의 종류를 달리하고 처리방법을 변경시켰을 때 THMs 및 유기물의 제거정도를 조사하였다. 산화제로 처리된 $ClO_2$가 다른 산화제인 $Cl_2,\;NH_2Cl,\;KMnO_2$ 및 $O_3$ 보다 THMs 생성억제와 THMs의 전구물질인 유기물을 제거시키는데 가장 효율적이었다. 산화제$(Cl_2,\;NH_2Cl,\;KMnO_4,\;ClO_2,\;O_3)$를 응집 이후에 처리하였을 때 유기물의 양은 거의 변화가 없었으나 THMs의 생성량은 응집 이전 처리보다 약 $36.7{\sim}8.2%$ 정도 감소하였다. 수중 유기물을 응집 제거시키기 위하여 응집제로 alum과 ferric sulfate를 처리하였을 때 응집 효율은 유기물의 분자량 분포에 따라 상이하게 나타났다. THMs 제거 및 생성 억제를 위한 활성탄의 처리는 여과 이후의 처리가 산화제 처리 이전의 활성탄 처리보다 효과적이었다.

• Environmental Engineering Research
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• 제21권4호
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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.

• 한국물환경학회지
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• 제21권1호
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• pp.7-13
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• 2005

With the appearance of pathogenic microorganisms, which were resistant to free chlorine, the significant attention to the necessity of powerful alternative disinfection methods such as ozone, chlorine dioxide, LTV irradiation to inactivating pathogens has been increased in water treatment. Among these alternative disinfection methods, ozone is well known as strong biocidal method and the usage of ozone is also increasing in Korea. However, in Korea, there has been no report on the quantitative study of Cryptosporidium parvum with ozone and its evaluation in advanced drinking water treatments. This study reports on the methodology for predicting the ozone inactivation of Cryptosporidium parvum by ozone disinfection in advanced drinking water treatment. The method is based on the fact that a specific inactivation level of microorganisms is achieved at a unique value of ozone exposures, independent of ozone dose and type of water, and quantitatively described by a delayed Chick-Watson model. The required values ${\bar{C}}T$ for 2 log inactivation of Cryptosporidium parvum was $6.0mg/L{\cdot}min$ and $15.5mg/L{\cdot}min$ at $20^{\circ}C$ and $5^{\circ}C$, respectively. From this obtained Cryptosporidium parvum inactivation curves and calculated ${\bar{C}}T$ values of advanced drinking water treatment water in Korea with FIA (Flow injection alaysis), we can predict that water treatment plant can achieve a 1.1~1.8 log inactivation and 0~0.4 log inactivation at $20^{\circ}C$ and $5^{\circ}C$, respectively. This methodology will be useful for drinking water treatment plants which intend to evaluate the disinfection efficiencies of their ozonation process without full scale test and direct experiments with Cryptosporidium parvum.

• 한국환경과학회지
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• 제21권7호
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• pp.837-843
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• 2012

The aims of this study were to investigated the occurrence of caffeine and carbamazepine in Nakdong river basin (8 mainstreams and 2 tributaries) and the behavior of caffeine and carbamazepine under drinking water treatment processes (conventional and advanced processes). The examination results showed that caffeine was detected at all sampling sites (5.4~558.5 ng/L), but carbamazepine was detected at five sampling sites (5.1~79.4 ng/L). The highest concentration level of caffeine and carbamazepine in the mainstream and tributaries in Nakdong river were Goryeong and Jinchun-cheon, respectively. These pharmaceutical products were completely removed when they were subject to conventional plus advanced processes of drinking water treatment processes. Conventional processes of coagulation, sedimentation and sand-filtration were not effective for their removal, while advanced processes of ozonation and biological activated carbon (BAC) filtration were effective. Among these pharmaceuticals, carbamazeoine was more subject to ozonation than caffeine.

• 한국막학회:학술대회논문집
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• 한국막학회 2004년도 Workshop
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• pp.57-68
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• 2004

A demonstrative operation of a membrane system with its caparity of 3,600m$^3$/d was carried out using reservoir water as raw water for the application of membrane filtration system to drinking water treatment. The operation was undertaken at a constant flux of 0.9 m$^3$/m$^2$/d for three months. Backwashing with NaClO of 3 ppm was allowed for 30 seconds every 20 minutes of filtration. Physical cleaning was introduced after 69 times of filtration/backwashing cycle with air-scrubbing and backwashing for 1 minute, and flushing for 2 minutes. In this study, water treatment performance was investigated compared with the existing rapid sand filtration process. The membrane system was operated with no significant problems during the test period. Higher water quality was obtained in the membrane filtration than in the rapid sand filtration in terms of particulate matters such as turbidity and microbes. Although the finished water of the membrane filtration contained slightly higher concentration in dissolved matters than that of the conventional one, it met the drinking water standard. The demonstrative operation showed that membrane filtration has a reliability in drinking water treatment. Researches should be needed on cost analysis through long-term operation and optimization of operation condition for further application.

• 수도
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• 통권28호
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• pp.27-36
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• 1983

Oxidation process constitute an important and often indispensable measure in the reliable production of safe drinking water. Optimal introduction of oxidation processes into the treatment of drinking water requires an exact knowledge of the reactions taking place and of their interrelationships. It is the aim of this paper to review the necessary knowledge in summarized form.