• 생태와환경
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• 제43권4호
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• pp.453-458
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• 2010

DOC (Dissolved Organic Carbon) is an operational terminology for organic carbon molecules dissolved in natural waters. DOC has been studied by ecologists extensively, because it plays a key role in various ecological functions such as substrates for secondary production and the carbon cycle. DOC also represents a substrate for microbial growth within potable water distribution systems, and can react with disinfectants (e.g., chloride) to form harmful disinfection by-products. In addition, residual DOC may carry with it organically bound toxic heavy metals. DOC in aquatic ecosystems may ultimately be transported to the oceans, or released back to the atmosphere by heterotrophic respiration, which can accelerate global climate change. There is evidence that DOC concentrations in aquatic ecosystems are increasing in many regions of the world including Europe, North America, and even in Korea. Land use changes, elevated temperature, elevated $CO_2$, recovery from acidification, and nitrogen deposition have been proposed as mechanisms for the trend. However, the key driving mechanism is yet to be conclusively determined. We propose that more extensive and longer-term observations, research of chemical properties of DOC, impacts of elevated DOC on environmental issues and interdisciplinary approaches are warranted as future studies to fill the gaps in our knowledge about DOC dynamics.

• Environmental Analysis Health and Toxicology
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• 제17권4호
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• pp.285-298
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• 2002

In Korea, no CRA (comparative risk analysis) studies have been undertaken, nor have their methodologies of such studies been established. Therefore, the objectives of this study were to establish the framework of CRA consisting of health risk, economic risk and perceived risk, and to estimate and compare these risks among the three environmental problems of air pollution, indoor air pollution and drinking water contamination, which are themselves subject to the eight sub -problems of hazardous air pollutants (HAPs), regulated pollutants (representative as PM 10) and dioxins (PCDDs/PCDFs) in air pollution, indoor air pollutants (IAPs) and radon in indoor air pollution, and drinking water pollutants (DWPs), disinfection by -products (DBPs) and radionuclides in drinking water contamination in Seoul, Korea. After which, the priorities of these problems were set by individual and integrated risk. From the results, the rankings of both health risk and economical risk were in the following order: radon, PM10, IAPs, HAPs, DWPs, dioxins, DBPs, and radionuclides among the eight sub problems. On the contrary, the ranking of perceived risk was in the following order: HAPs, dioxins, radionuclides, PM10, DWPs, IAPs, Radon and then DBPs among the eight sub-problems.

• 한국환경과학회지
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• 제23권9호
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• pp.1655-1662
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• 2014

A comprehensive fractionation technique was applied to a set of water samples obtained along drinking water treatment process with ozonation and biological activated carbon (BAC) process to obtain detailed profiles of dissolved organic matter (DOM) and to evaluate the haloacetic acid (HAA) formation potentials of these DOM fractions. The results indicated that coagulation-sedimentation-sand filtration treatment showed limited ability to remove hydrophilic fraction (28%), while removal of hydrophobic and transphilic fraction were 57% and 40%, respectively. And ozonation and BAC treatment showed limited ability to remove hydrophobic fractions (6%), while removal of hydrophilic and transphilic fractions were 25% and 18%. The haloacetic acid formation potential (HAAFP)/dissolved organic carbon (DOC) of hydrophilic fraction was the highest along the treatment train and HAAFP/DOC of hydrophilic fraction was higher than hydrophobic and transphilic fraction as 23%~30%, because of better removal for hydrophobic fraction both in concentration and reactivity.

• Environmental Analysis Health and Toxicology
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• 제12권3_4호
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• pp.31-41
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• 1997

Public concerns about hazardous health effect from the exposure to organic by-products of the chlorination have been increased. There are numerous studies reporting that chlorination of drinking water produces numerous chlorinated organic by-products including THMs, HAAs, HANs. Some of these products are known to be animal carcinogens. The purpose of this study was to estimate health risk of DBPs by chlorinated drinking water ingestion in Seoul based on methodologies that have been developed for conducting risk assessment of complex-chemical-mixture. The drinking water sample was collected seperately at six water treatment plant in Seoul at March, April, 1996. In tap water of households in Seoul, DBPs were measured wilfh the mean value of 36.6 $\mu$g/L. Risk assessment processes,. which include processes for the estimation of human cancer potency using animal bioassay data and calculation of human exposure, entail uncertainties. In the exposure assessment process, exposure scenarios with various assumptions could affect the exposure amount and excess cancer risk. The reference dose of haloacetonitriles was estimated to be 0.0023 mg/kg/day by applying dibromoacetonitrile NOAEL and uncertainty factor to the mean concentration. In the first case, human excess cancer risk was estimated by the US EPA method used to set the MCL (maximum contaminant level). In the second and third case, the risk was estimated for multi-route exposure with and without adopting Monte-Carlo simulation, respectively. In the second case, exposure input parameters and cancer potencies used probability distributions, and in the third case, those values used point estimates (mean, and maximum or 95% upper-bound value). As a result, while the excess cancer risk estimated by US EPA method considering only direct ingestion tended to be underestimated, the risk which was estimated by considering multi-route exposure without Monte-Carlo simulation and then using the maximum or 95% upper-bound value as input parameters tended to be overestimated. In risk assessment for Trihalomethanes, considering multi-route exposure with adopting Monte-Carlo analysis seems to provide the most reasonable estimations.

• 한국응용과학기술학회지
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• 제31권4호
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• pp.688-693
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• 2014

본 연구는 생활주변에서 오존수를 쉽게 활용할 수 있도록 오존수 발생장치의 활용성을 증가시키고 한 동작으로 작동하는 시스템을 개발하고자 한다. 더 나아가 올리브 오일과 오존과 반응시켜 제조하는 기술에 적용하고자 한다. 기존의 경우 대부분이 오존수 시스템이 아닌 오존발생기 위주의 제품이 많다. 오존수기의 경우 펌프로 강제 흡입시키는 일반압력 방식으로 오존가스 누출 위험요소가 내포 되어 있으나, 본 과제의 경우 인젝터를 이용하여 물의 유입여부에 따른 오존의 발생과 흡입을 제한하고 있어 기존 제품의 오존 누출에 의한 위험을 최소화하였다. 인젝터 방식의 단점에도 불구하고 미생물 살균능을 유지하는 것으로 본 연구에서 사용된 인젝터 방식 오존수 제조 장치의 효용성을 알 수 있었다.

• 상하수도학회지
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• 제20권1호
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• pp.27-34
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• 2006

This study was conducted to evaluate the performance of a membrane bioreactor filled with high concentration of powdered activated carbon (HCPAC-MBR) to reduce DBPs at the drinking water treatment. The pilot system was installed after the rapid sand filtration process whose plant was the conventional treatment process. The removal efficiencies of DBPs were measured during pilot operation period of 2 years. HAA and THM removal rates could be maintained around 80~90% without any troubles and then tremendous reduction of HAA and THM reactivity were observed more than 52%. The average removal rate of HAA formation potential (FP) and THM formation potential (FP) were 70.5% and 67.6% respectively. It is clear that the PAC membrane bioreactor is highly applicable for advanced water treatment to control DBPs.

• 한국환경과학회지
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• 제24권1호
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• pp.65-71
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• 2015

This study accessed the adsorption characteristics of the 9 trihalomethanes (THMs) on coal-based granular activated carbon (GAC). The breakthrough appeared first for $CHCl_3$ and sequentially for $CHBr_2Cl$, $CHBr_3$, $CHCl_2I$, CHBrClI, $CHBr_2I$, $CHClI_2$, $CHBrI_2$, and $CHI_3$. The maximum adsorption capacity (X/M) for the 9 THMs with apparent breakthrough points ranged from $1,175{\mu}g/g$ (for $CHCl_3$) to $11,087{\mu}g/g$ (for $CHI_3$). Carbon usage rate (CUR) for $CHCl_3$ was 0.149 g/day, 5.5 times higher than for $CHCl_3$ (0.027 g/day).

• 한국의류산업학회지
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• 제21권2호
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• pp.237-243
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• 2019

This study analyzed satisfaction with and washing of newborn clothing (especially the innerwear washing behaviors) which are considered to be the most basic items among newborn clothing.The survey was conducted on mothers with children under 24 months old. Using an average of 6.7 innerwear items that were changed average 2.3 times a day with baby formula and breast milk representing the main contaminants. When washing clothes for a newborn, respondents were mainly concerned with: rinsing residual detergent, removing stains and contaminants, and sterilization and disinfection. Items were washed by a laundry label to prevent clothes damage. A baby-friendly or environmentally-friendly detergent was used to wash before being worn after purchase was separated and washed in various washing courses of the washing machine every day, boiled, rinsed an average 3.6 times, and dried mainly in the sun. Environmentally friendly cotton (59.5%) and organic cotton (41.6%) products were mainly used; however, items were washed separately from regular laundry. Respondents were satisfied with methods of washing. Consumers are concerned about washing because they think that washing affects a newborn's health. Therefore, it is necessary to provide consumers with appropriate information on washing and establish regulations for the use of harmful substances in newborn clothing and detergents.

• 식품과학과 산업
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• 제50권3호
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• pp.39-50
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• 2017

In order to secure competitiveness of the home meal replacement (HMR) industry from a long-term perspective, development of packaging and processing technologies must be achieved. The development of technology that can secure freshness, nutrition, and taste but secures the shelf life is the key to the future growth of HMR. The future of HMR can be considered in terms of nutrition, environment and safety. From the nutritional point of view, it is expected that development of healthy HMR such as low-salt, low-sugar, low-fat, and high fiber and premium HMR with functional ingredient enhanced, and personalized HMR for silver, infant and patients will be done. And it is expected that development of HMR utilizing environmentally friendly food or local food, development of energy reduction and environmentally friendly disinfection technology, development of environmentally friendly packaging material, and providing information on HMR preparation using QR code and RFID from the environmental and safe point of view.

• 한국환경보건학회지
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• 제46권2호
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• pp.150-158
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• 2020

Objective: This study is designed to measure the concentration of DBPs (disinfection by-products) in pool water and in air and to estimate the carcinogenic potential through the evaluation of inhalation exposure. Methods: The subjects were six indoor swimming pools with many users in Gwangju. Samples of pool water and indoor air were taken every one month from August 2018 to August 2019 and analyzed for eight swimming pool standards. Three-liter air samples were collected and the VOCs were analyzed using GC/MS directly connected to thermal desorption. Results: pH was 6.8-7.5 and the concentration of free residual chlorine in pool water was 0.40-0.96 ?/ℓ. Physicochemical test items such as KMnO₄ consumption and heavy metal items such as Aluminum met existing pool hygiene standards. No VOC materials were detected except for the DBPs. The concentration of THMs in the pool water was 11.05-41.77 ㎍/L and the THMs mainly consist of Chloroform (63-97%) and BDCM (3-31%). The concentration of indoor air THMs is 13.24-32.48 ㎍/㎥ and consists of Chloroform. The results of carcinogenic assessment of chloroform in the indoor swimming pool via inhalation exposure were 2.0 to 6.4 times higher than the 'acceptable risk level' suggested by the US EPA. Conclusions: The concentration of THMs in the pool water is 11.05-41.77 ㎍/L, most of which is chloroform. In addition, the concentration of indoor air THMs is 13.24-32.48 ㎍/㎥. The result of carcinogenic assessment of chloroform was 2.0 to 6.4 times higher than the 'acceptable risk level' suggested by the US EPA.