• Title, Summary, Keyword: Contamination degree evaluation

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Studies on the Evaluation Method of Heavy Metal Contamination Degree in the Han River (한강 저질중의 중금속 오염도 평가 방법에 관한 연구)

  • 어수미;박성배
    • Journal of Environmental Health Sciences
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    • v.18 no.1
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    • pp.47-57
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    • 1992
  • This study was performed to evaluate contamination degree of heavy metals in sediments of Han River, compared with other nation's evaluation method. The results were as follows 1. The contamination Ratio calculation method by heavy metal concentration in differnt fraction size has a limitation to apply to all of the areas of Han river because of its characteristics of sediment. As a result, this method applied to only 4 areas of Pal Dang, Wang Sook Chon, Uk Chon, and Bul Kwang Chon, and Contmination Ratio of heavy metals in those areas were relatively low of below 3. So it's considered that those areas have less contaminated from anthropogenic contaminants. 2. The Contamination Ratio calculation method by heavy metal concentration in different areasthat of upper area to be background level-has a limitation also to apply to Han river. But it is considered that this method was relatively suitable to apply, so it should be prepared evaluation standand method for them. Contamination ratio from background level as Pal Dang area were most high in An Yang Chon. So it must be prepared purification and control measure at An Yang Chon.

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Evaluation of Artificially Contaminated Suspension Insulators for Transmission (송전용 현수애자의 인공오손 평가)

  • Kim, Chan Young;Choi, In-Hyuk;Hong, Dong-Suk;Kim, Beom-Soo
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.123-127
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    • 2002
  • This paper presented the results of evaluation of artificially contaminated suspension insulators for transmission lines. The suspension insulators were contaminated with kaolin and clay which were included various amount of natural salt. The degree of contamination were evaluated by measuring equivalent salt deposit density(ESDD). Then, the leakage currents were measured as a function of applied voltage, degree of contamination, humidity.

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Diagnosis Technique of Surface Contamination Degree for EPDM Insulator according to Variation of Environment Condition (환경조건의 변화에 따른 EPDM 애자의 표면 오손정도의 진단기술)

  • Park, Jae-Jun;Choi, In-Hyuk;Kim, Jeong-Boo
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.17 no.10
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    • pp.1132-1141
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    • 2004
  • The waveforms of the leakage currents for the surface discharge according to the degree of salt contamination and the variation of environmental condition on the EPDM polymer insulators, were shown in this paper. The variation phenomena of fundamental wave, 3rd and 5th harmonic waveforms were also shown from the beginning of the applied voltage and to the flashover voltage. To develop the technique of percentage contamination degree of EPDM polymer insulator according to the variation of environmental condition, the distortion degree of 3rd and 5th harmonic wave to the fundamental wave was utilized through the spectrum analysis for the waveforms of leakage current in the simulation of salt and fog test. The fact that distortion degree % of 3rd and 5th harmonics for fundamental wave is a necessary indicator for the assessment of contamination degree for the polymer insulators, was known.

Quantification and Evaluation of Groundwater Quality Grade by Using Statistical Approaches (통계적 분석 방법을 이용한 국가지하수수질측정망의 오염 등급 정량화 및 평가)

  • Yoon, Hee-Sung;Bae, Gwang-Ok;Lee, Kang-Kun
    • Journal of Soil and Groundwater Environment
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    • v.17 no.1
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    • pp.22-32
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    • 2012
  • This study suggests a method to grade groundwater quality quantitatively using statistical approaches for evaluating the quality of groundwater in wells included in the Groundwater Quality Monitoring Network (GQMN). The proposed analysis method is applied to GQMN data from 2001 to 2008 for nitrate nitrogen, chloride, trichloroethylene, potential of hydrogen (pH), and electrical conductivity. The analysis results are obtained as groundwater quality grades of the groundwater representing each of the monitoring stations. The degree of groundwater contamination is analysed for water quality parameters, district, and usage. The results show that the degree of groundwater contamination is relatively high by nitrate nitrogen, bacteria and electrical conductivity and at Seoul, Incheon, Gwangju, Gyeonggido and Jeollado. The degree of contamination by nitrate nitrogen and trichloroethylene is especially high when the groundwater is used for agricultural and industrial water, respectively. It is evaluated that potable groudnwater in GQMN is significantly vulnerable to nitrate nitrogen and bacteria contamination.

Effects of Inorganic Coagulants on Sizing and Contamination in Newsprint Mill (무기 응결제가 신문용지의 사이즈도와 공정오염에 미치는 영향)

  • Lee, Tai Ju;Seo, Jin Ho;Lee, Kwang Seob;Jeong, Sung Hyun;Ryu, Jeong Yong
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.47 no.3
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    • pp.40-46
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    • 2015
  • For some Korean newsprint mill, addition level of aluminum sulfate has been reduced because sulfur from aluminum sulfate has detrimental effect on the efficiency of anaerobic water treatment. At this moment, an unexpected decrease in sizing degree of TMP mixed newspaper was occurred. The phenomena means that hydrophobic substance usually originated from TMP cannot be fixed on the paper. This study focused on effect of alum and PAC on sizing of paper and contamination. Also, substitutability of PAC was discussed as a possible alternatives of aluminum sulfate under anaerobic condition of water treatment. Evaluation of sizing degree and pitch deposit potential were performed at the varied addition level of PAC and aluminum sulfate. Hydrophobic substance mainly derived from TMP could be fixed on the surface of fiber by PAC. Fines retention was not changed by replacing aluminum sulfate with PAC. Additionally, fixing of hydrophobic substance without excessive agglomeration can be enhanced by PAC with low molecular weight. Consequently, sizing degree of newspaper and contamination of recycling process of ONP can be controlled by low molecular weighted PAC.

Studies on the Contamination Degree of Effluent from the Sewage Purification System and Septic Tank (오수정화시설 및 정화조 방류수의 수질오염도에 관한 연구)

  • 어수미;이홍근
    • Journal of Environmental Health Sciences
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    • v.17 no.2
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    • pp.35-40
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    • 1991
  • This study was performed to investigate the contamination degree of effluent from the sewage purification system and septic tank. The 711 samples, were collected from the large size tank located in Seoul from Mar. to June 1991. The results were as follows 1. The pH values of effluent were largely neutral of 6.96 in sewage and 7.43 in septic tank. 2. The average concentration of BOD was 48.18 mg/l in sewage and 127.0 rng/l in septic tank. 3. The average concentration of SS was 40.8mg/l in sewage and 90.5rng/l in septic tank. 4. In the analysis of nutrient salts, the average concentration of NH$_{3}$-N was 31.62mg/l in sewage and 88.79 mg/l in septic tank. 5. In the analysis of correlation among items, BOD, SS, NH$_{3}$-N and PO$_{4}$-P were higly correlated beween items. 6. As a results of above analysis, it is considered as desirable evaluation method of effluent not through the only item but through the integrated items.

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Quantification of Uncertainty Associated with Environmental Site Assessments and Its Reduction Approaches (부지 오염도 평가시 불확실성 정량화 및 저감방안)

  • Kim, Geonha;Back, JongHwan;Song, Yong-Woo
    • Journal of Soil and Groundwater Environment
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    • v.19 no.1
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    • pp.26-33
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    • 2014
  • Uncertainty associated with a sampling method is very high in evaluating the degree of site contamination; therefore, such uncertainty affects the reliability of precise investigation and remediation verification. In particular, in evaluating a site for a small-sized filling station, underground utilities, such as connection pipes and oil storage tanks, make grid-unit sampling impossible and the resulting increase in uncertainty is inevitable. Accordingly, this study quantified the uncertainty related to the evaluation of the degree of contamination by total petroleum hydrocarbon and by benzene, toluene, ethylene, and xylene. When planning a grid aimed at detecting a hot spot, major factors that influence the increase in uncertainty include grid interval and the size and shape of the hot spot. The current guideline for soil sampling prescribes that the grid interval increase in proportion to the area of the evaluated site, but this heightens the possibility that a hot spot will not be detected. In evaluating a site, therefore, it is crucial to estimate the size and shape of the hot spot in advance and to establish a sampling plan considering a diversity of scenarios.

Heavy metals contamination in coastal sediments by the large discharge from wastewater treatment plant (하수종말 처리장 처리수의 해양 방류와 퇴적물의 중금속 오염)

  • Kwon Young Tack;Lee Chan Won
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.1 no.1
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    • pp.83-92
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    • 1998
  • Heavy metals concentration in superficial sediment of effluent discharging area was rapidly increased by annual loadings of Zn(8.465 Kg), Ni(3,291 Kg), Cu(1,636 Kg) and Pb(1,250 Kg) from sewage effluent of 63×10/sup 6/ m³/yr. In a consequent result, specially the concentrations of Zn and Cu in the sediment were three times higher than preindustrial reference values. The evaluation by multiple ecological risk indices showed that heavy metals contamination in sediment of discharging area was 'heavily Polluted level' by sediment quality criteria and increased 2.6 times by the degree of contamination. It was also judged that toxicological effects of sediment receiving the primary effluent would occasionally (16~47%) occur by guidelines for adverse biological effect.

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Analysis of Microbial Contamination and Antibacterial Effect Associated with Toothbrushes

  • Kim, Ji-Hyang;Kim, Da-Ae;Kim, Hee-Soo;Baik, Ji-Yeon;Ju, So-Hee;Kim, Seol-Hee
    • Journal of dental hygiene science
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    • v.18 no.5
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    • pp.296-304
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    • 2018
  • The purpose of this study was to propose a method for the effective management of toothbrush contamination. Toothbrush microbial contamination was analyzed according to the duration of toothbrush use, frequency of toothbrush use per day, and toothbrush storage location. We also analyzed the microbial reduction effect of vinegar, antimicrobial mouth rinse, bamboo salt, and baking soda, which are sterilization materials that can be easily used every day. We collected 45 toothbrushes from university dormitories from May to June 2018. To determine the degree of microbiological contamination with general bacteria, coliform bacteria, and Staphylococcus aureus, bristle samples were cultured at $36^{\circ}C$ for 24 hours using 3M$^{TM}$ Petrifilm plates and then measured based on Petrifilm evaluation criteria. Toothbrush microorganisms were analyzed according to the duration of use, frequency of use per day, storage location, and effect of each sterilization material. General bacteria, coliforms, and S. aureus contamination increased with frequency and duration of use (p<0.05). In particular, S. aureus showed a statistically significant increase to 36.15 CFU/ml after 1 month, 504.23 CFU/ml after 2 months, and 2,386.67 CFU/ml after 3 months (p<0.05). We found that 1% vinegar was the most effective substance for reducing general bacteria, coliforms, and S. aureus. In addition, 1% antimicrobial mouth rinse solution applied for 5 minutes was the most effective in reducing S. aureus. It is crucial to recognize the importance of toothbrush care and store toothbrushes in a dry place and replace them periodically. We recommend use of vinegar and antimicrobial mouth rinse solution to disinfect toothbrushes. These should be applied as a 1% solution for at least 1 minute. Proper care of toothbrushes is important in maintaining oral health as well as overall health. Instructions on toothbrush care should be given when teaching children or adults how to brush teeth.

Analysis of Trends in Dose through Evaluation of Spatial Dose Rate and Surface Contamination in Radiation-Controlled Area and Personal Exposed Dose of Radiation Worker at the Korea Institute of Radiological and Medical Sciences (KIRAMS)

  • Lee, Bu Hyung;Kim, Sung Ho;Kwon, Soo Il;Kim, Jae Seok;Kim, Gi-sub;Park, Min Seok;Park, Seungwoo;Jung, Haijo
    • Progress in Medical Physics
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    • v.27 no.3
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    • pp.146-155
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    • 2016
  • As the probability of exposure to radiation increases due to an increase in the use of radioisotopes and radiation generators, the importance of a radiation safety management field is being highlighted. We intend to help radiation workers with exposure management by identifying the degree of radiation exposure and contamination to determine an efficient method of radiation safety management. The personal exposure doses of the radiation workers at the Korea Institute of Radiological & Medical Sciences measured every quarter during a five-year period from Jan. 1, 2011 till Dec. 31, 2015 were analyzed using a TLD (thermoluminescence dosimeter). The spatial dose rates of radiation-controlled areas were measured using a portable radioscope, and the level of surface contamination was measured at weekly intervals using a piece of smear paper and a low background alpha/beta counter. Though the averages of the depth doses and the surface doses in 2012 increased from those in 2011 by about 14%, the averages were shown to have decreased every year after that. The exposure dose of 27 mSv in 2012 increased from that in 2011 in radiopharmaceutical laboratories and, in the case of the spatial dose rate, the rate of decrease in 2012 was shown to be similar to the annual trend of the whole institute. In the case of the surface contamination level, as the remaining radiation-controlled area with the exception of the I-131 treatment ward showed a low value less than $1.0kBq/m^2$, the annual trend of the I-131 treatment ward was shown to be similar to that of the entire institute. In conclusion, continuous attention should be paid to dose monitoring of the radiation-controlled areas where unsealed sources are handled and the workers therein.