• Title/Summary/Keyword: contamination possibility

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The Study on the Properties of Calcined Oyster Shell & Hwang-To Powder (황토를 혼합 소성한 굴패각 미분말의 물성에 관한 연구)

  • Jung, Joo-hyung;Park, Min-Soo;Jung, Min-Soo;Kim, Hyo-Youl;Kang, Byung-Hee
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2007.11a
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    • pp.41-44
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    • 2007
  • Recently, the strenuous industrial waste is scattered and one of the oyster also make the serious environmental contamination. The purpose of this study is investigating an utilization ability as calcium binder of the oyster with Hwang-To according to a rate(10%, 20%, 30%, 40%, 50%). This study grasp physical properties of the oyster powder, bake production of the paste, and conduct the flow test, stiff time test and strength test. According to baking condition, strength of $1000^{\circ}C$(120minutes, rate 30%) is higher than any other condition. The oyster powder from above $900^{\circ}C$ seem possibility as binder hereafter. It is thought that the continuous research will be necessary.

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Preliminary Experiments on Pozzonalic Activity of Dredged Sea Soil (소성 해양 준설토의 포졸란 반응성 시험)

  • Kim, Ji-Hyun;Moon, Hoon;Lee, Jae-Yong;Chung, Chul-Woo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2014.11a
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    • pp.49-50
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    • 2014
  • Dredged sea soil contains various contaminants. First priority to recycle dredged sea soil is to pretreat it to remove various contaminants because recycling dredge sea soil without any pre-treatment may cause a secondary contamination due to the leaching of hazardous chemicals. In this study, pretreated dredged sea soil was used to investigate pozzolanic activity. The properties of pretreated dredged sea soil were investigated, the method for heat treatment was determined, and the compressive strength of mortar using dredged sea soil was examined to evaluate pozzolanic activity. According to the results, pretreated dredged sea soil has some possibility to work as a pozzolanic material. When dredged sea soil was heat treated for 90min at 550℃, compressive strength was shown to be comparable to that of plain cement mortar.

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Evaluation of Seawater Intrusion on Costal Groundwater using Systematic Analytical Method (계층적 분석방법을 이용한 해수침투 영향 평가)

  • Kim, Chang-Hoon;Kim, Nam-Ju;Park, Youngyun
    • The Journal of Engineering Geology
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    • v.27 no.1
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    • pp.1-7
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    • 2017
  • Seawater intrusion was evaluated using electrical conductivity, chemical proxies, and oxygen isotopic compositions in coastal area. It seems that groundwater in the area where the electrical conductivity is over $3,000{\mu}S/cm$ is influenced by seawater. However, it is very difficult that seawater intrusion is distinguished from other contaminants using the electrical conductivity. The chemical proxies and oxygen and hydrogen isotopic compositions can quantitatively estimate seawater intrusion. However, these method is a costly disadvantage. Therefore, firstly, groundwater contamination by seawater intrusion was evaluated using electrical conductivity and then the additional chemical and isotopic analysis were conducted in areas where possibility of contamination by seawater intrusion is high. These systematic analytical method can reduce analytical cost to quantitatively evaluate influence of seawater intrusion on coastal groundwater and may improve efficiency of analytical method for seawater intrusion.

A Numerical Study on Flow Field near the Roller Conveyor for Flat Panel Display (평면 디스플레이 기판 운송용 롤러 컨베이어 주위의 유동장에 관한 수치해석 연구)

  • Jeon, Hyun-Joo;Kim, Hyoung-Jin;Im, Ik-Tae
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.10 no.1
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    • pp.6-11
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    • 2009
  • Flow field in a roller conveyor system, induced from the movement of a cassette in which glasses for flat panel display are loaded, is numerically studied in this paper. Contamination on the glass surface by dust particles produced from mechanical friction between roller and cassette is predicted from the analysis results of flow fields. Results show that a large swirl flow is formed under the moving cassette with constant speed. This swirl flow is confined only under the cassette because two main streams from the backward and the fan filter unit on the top ceiling are sufficiently strong. Therefore, it can be said that possibility of the contamination by the particles originated from the friction is relatively low. It is also revealed that flow direction between glass plates is changed according to the speed of the cassette movement due to the shear force of glass plates.

Estimation of the Number of Salmonellosis Using Microbial Risk Assessment Methodology (미생물 위해성 평가 방법을 이용한 살모넬라 발생수 추정)

  • 최은영;박경진
    • The Korean Journal of Community Living Science
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    • v.15 no.2
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    • pp.167-177
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    • 2004
  • The number of foodborne salmonellosis was estimated by using microbial risk assessment(MRA) methodology and the possibility of application was studied through comparison with previous results. The contamination levels of Salmonella sp. were estimated by using published domestic studies(1997∼2000) and monitoring data (1999∼2001) from food-safety related institutes. Data on food consumption came from the 2001 National Health and Nutrition Survey, and dose-response models from studies in other countries. Simulation results showed that there were 753,368 cases of salmonellosis in Korea in 1 year, which is about 115 times that reported in previous years and lower than the WHO's estimation increase. From these results, microbial risk assessment is likely to be available for estimation of the number of foodborne illnesses and determination of the order of priority in food-safety management. Butthe verification methods are not established and most of the data on contamination levels of foodborne bacteria, food consumption, and dose-response relationships have not been established. In addition, the actual conditions of circulation, storage and cooking must be studied further.

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Evauation of Management & Hygienic Status of High School Foodservice using ATP Bioluminescence Assay (고등학교 급식시설 운영실태 및 ATP Bioluminescence를 이용한 위생상태 조사연구)

  • Kye, Seung-Hee;Hwang, Seong-Hee
    • The Korean Journal of Food And Nutrition
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    • v.30 no.3
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    • pp.515-524
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    • 2017
  • An investigation was conducted to evaluate the hygienic status of 53 high school foodservice systems in Gyeonggi province by using hygiene management guide checklist, ATP bioluminescence assay of food utensils were conducted during process. The 5 hygiene management guide checklist groups about personal hygiene, cooking facilities control, cross contamination control, cook and storage control, management control were checked by experts and had good grades but there were some inadequate behaviors on observation. Total cleaning levels were inadequate, including hand, rubber gloves, aprons, knives, food tray, machine and instruments. The possibility of cross contamination is also noted in handles for refrigerators, ovens, food dryers, hand washing. It was also noted that there were too much work on the nutritionist and cook, additional personnel need to be added. lack of space, deterioration of facilities were identified in some high school foodservice systems. ATP bioluminescence assay was conducted on surface of food facilities, ATP ranged $1,393{\pm}5,041.2RLU$ on yellow gloves, $244{\pm}258.7RLU$ on pink gloves, $3,780{\pm}11,418.6RLU$ on apron, $49,056{\pm}62,831.4RLU$ on refrigerator grip, $41,422{\pm}61,259.8RLU$ in oven, $31,407{\pm}41,344.9RLU$ on hand cleaning board.

Subgrouping of Pseudomonas aeruginosa Isolates by Resemblance Coefficiency of the Cellular Fatty Acid Analysis (수환경 녹농균의 세포막 지방산 유사도 분석에 의한 Subgrouping과 활용)

  • 정현미;김동빈
    • Korean Journal of Microbiology
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    • v.38 no.4
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    • pp.276-280
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    • 2002
  • To find the applicability of resemblance of the fatty acid methy1 ester (FAME) profile analysis to the primary examination for the tracing P. aeruginosa contamination in the environment and water plants, we designed this study. Of6l P. aeruginosa isolates including 3 reference strains, 4 fecal or soil isolates and 54 water isolates, the resemblance coefficiencies of the FAMEs were calculated as euclidian distance (ED) and expressed as dendrogram. The 61 strains were clustered as the same group in the ED 8.4, and divided into 4 subgroups in the ED 6.9. The water isolates from Han River were classified into distinctively different subgroups from reference strains. These results provide the possibility of the dendrogram from FAME profile as a useful tools for tracing contamination as well as for identifying the species, especially in case of P. aeruginosa.

Contamination of Heavy Metals from Dongmyeong Au-Ag Mine Area (동명 금-은 광산 주변의 중금속 오염)

  • 이광춘;김세현;이승호;서용찬
    • Economic and Environmental Geology
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    • v.36 no.1
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    • pp.17-25
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    • 2003
  • Researches were carried out to investigate the characteristics and concentration of heavy metal elements of stream water through Dongmyoung abandoned metal mine and soil adjacent to the mine. The pH range of water was 5.9∼7.1 that implies the water environment was acidic to neutral. The contents and distribution aspects of heavy metals in water samples varied with geochemical characteristics of element, but the concentration of heavy metals has the tendency of increase closer to the mine in general. The results of soil analysis show that total heavy metal concentration of agricultural soil near mine was far lower than those of ore tailing and dumping site. Therefore, the effects of the abandoned mine on stream water and agricultural products were supposed to be insignificant, particularly because the portion of absorbed carbonates and reducible fractions among total heavy metal concentration was relatively lower than the other. Since, however total heavy metal concentrations of mining site were relatively higher than those of adjacent region, there is a possibility of heavy metal difussion when the chemical environment of the site changes due to migration of surface and underground water. It is suggested that the preventive measures for water and soil pollution by the heavy metals would be considered around the region.

Feasibility study on shale gas wastewater treatment using membrane distillation (막 증발법을 이용한 셰일가스 폐수 처리 가능성 평가)

  • Cho, Hyeongrak;Choi, Yongjun;Lee, Sangho
    • Journal of Korean Society of Water and Wastewater
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    • v.30 no.4
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    • pp.441-447
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    • 2016
  • Development of shale gas has drawn increasing attention since it is one of promising alternative energy resources. However, contamination of groundwater and surface water during the extraction of shale gas is becoming a serious environmental issues, which brings the needs to treat wastewater generated from hydraulic fracking. In this study, the feasibility of membrane distillation (MD) for the treatment of shale gas wastewater was investigated using a laboratory scale experimental setup. Flat-sheet MD membranes were used to treat produced water from a shale gas well in the United States. Different configurations such as direct contact MD (DCMD) and air gap MD (AGMD) were compared in terms of flux and fouling propensity. The foulants on the surface of the membranes were examined. The results suggest that MD can treat the shale gas produced water containing more than 200,000 mg/L of total dissolved solids, which is impossible by other technologies such as reverse osmosis (RO) and forward osmosis (FO). In this study, we investigated the possibility of processing and characterization of shale gas produce wastewater using membrane distillation. Laboratory scale membrane distillation experimental device was developed. It was compared the flat-sheet direct contact membrane distillation and flat-sheet air gap membrane distillation. AGMD flux in lower than the flux of DCMD, it was expected that the contamination caused by organic matters.

Investigation on soil contamination and its remediation system in the vicinity of abandoned Au-Ag mine in Korea (휴/폐광 금은광산 주변의 토양오염조사와 복구시스템 연구)

  • 정명채
    • Economic and Environmental Geology
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    • v.32 no.1
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    • pp.73-82
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    • 1999
  • The objectives of this study are to investigate soil contamination in the vicinity of abandoned Au-Ag mine and to apply a remediation technique of liming to tailings. In the study area of the Imcheon Au-Ag mine, soils were sampled in and around the mine the analyzed by Atomic Absorption Spectrometry extracted by both 0.1N HCl and aqua regia. Elevated levels of Cd, Cu, Pb and Zn concentrations extracted by 0.1N HCl were found in soils taken from tailings site. These high contents directly influenced metal concentrations in soils taken in the vicinity of the site. This is mainly due to clastic movement by wind and effluent of mine waste water. In addition, relatively enriched concentrations of the metals were found in soils extrated by aqua regia due to strong decomposition of the samples compared with 0.1N HCl extration. According to the statistical approach, metal concentrations in soils by 0.1N HCl had a positive correlation with those by aqua regia extraction. Mine waste waters and stream waters were also sampled around the mine in spring and summer and analyzed by AAS for Cd, Cu, Pb and Zn, and by Ion Chromatography for anions. Like soils developed over tailings, significant levels of metals and sulphates were found in the mine waste waters ranging of 0.2~0.3, 0.5~2.0, 0.2~2.8, 30~50 and 1,240~4,700 mg/l of Cd, Cu, Pb, Zn and $SO_4^{2-}$, respectively. These elevated levels influenced in the stream waters in the vicinity of the tailings site. In seasonal variation of metal and anion contents, relatively high levels were found in waters sampled on summer due to leaching the metals and anions from tailings by rain. This study also examined the possibility of lime treatment for remediation of acid mine tailings and assumed to be 46 tones of pulverized lime for neutralization of the tailings.

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