• 제목/요약/키워드: pollution Factors

검색결과 1,033건 처리시간 0.032초

Optimization for Scenedesmus obliquus Cultivation: the Effects of Temperature, Light Intensity and pH on Growth and Biochemical Composition

  • Zhang, Yonggang;Ren, Li;Chu, Huaqiang;Zhou, Xuefei;Yao, Tianming;Zhang, Yalei
    • 한국미생물·생명공학회지
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    • 제47권4호
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    • pp.614-620
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    • 2019
  • Microalgae have been explored as potential host species for biofuel production. Environmental factors affect algal growth and cellular composition. The effects of several key environmental factors, such as temperature, light, and pH of the medium on the growth and biochemical composition of Scenedesmus obliquus were investigated in this study. The highest growth rate of microalgae was observed at an optimal temperature of 25℃, 150 μmol/(m2·s) light intensity, and pH 10.0. The biochemical composition analysis revealed that the carbohydrate content decreased at lower (20℃) or higher temperature (35℃), whereas the protein and lipid contents increase at these temperatures. The fluctuation of light intensity significantly affected the contents of protein, carbohydrate, and lipid. The protein levels varied greatly when the pH of the medium was below 7.0. The carbohydrate and lipid contents significantly increased at pH above 7.0.

소양호 지류하천의 비점오염원 유출특성에 관한 연구 (A Study on the Out Flow Characteristics of Non-Point Source Pollution in the Branch River of So-yang Lake)

  • 최한규;최창호;박수진
    • 산업기술연구
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    • 제29권B호
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    • pp.199-205
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    • 2009
  • This study selected Naerin Stream, Inbuk Stream and Buk Stream, branch rivers of Soyang Dam, also area of highland agriculture as test sites and measured flow and water quality, particularly eutrophication factors (BOD, COD, T-N, and T-P) in precipitation season and non precipitation season for a year, 2008. Based on the result, the study examined the change in water quality in relation to flow, and created flow discharged - pollution loads regression line by estimating pollution loads flowed from each branch river. And the study calculated annual pollution discharge loads for unit area and proposed regression equation on it by using regression analysis.

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Estimation of Risk from Air Pollution in the Underground Highway Proposed to Construct in Seoul, Korea

  • Lee, Ki-Young;Yukio-Yanagisawa
    • Journal of Korean Society for Atmospheric Environment
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    • 제9권E호
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    • pp.397-400
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    • 1993
  • The possible air pollution problems in a proposed underground highway are discussed using carbon monoxide (CO) as an indicator. Carbon monoxide concentrations in the underground highway depend on several factors, including the size of tunnel, the number of automobiles, the CO emission rate, and the tunnel ventilation rate. Using the estimated values, CO concentrations in the underground highway can be predicted. Without proper ventilation system, CO concentration in the underground highway can be dangerous level. However, the cost of operating the mandatory mechanical ventilation system may be tremendouslyy high and may be technically unrealistic to implement. If the underground highway is constructed with proper ventilation system, a continuous air pollution monitoring system with alarming function must be installed to alert personnel of serious air pollution built up in the underground highway. Traffic must be restricted, whenever the inside air pollution levels exceed agreed values. Short distances between evacuation exits are necessary for emergency situations or malfunction of ventilation system.

서울시민의 대기 환경에 관한 인식 및 태도 (A Study on Recognition and Attitude of Residents in Seoul City about Air Environment)

  • 이정주;김신도;이경용
    • 한국환경보건학회지
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    • 제21권4호
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    • pp.63-74
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    • 1995
  • The objective of this study were to identify the state of re. cognition and attitude of residents in Seoul city about air environment and to identify factors affecting attitude toward air environment. Study object was residents in Seoul city sampled by multistage random proportional sampling. Sample size was 0.0067%(500 persons) of total residents in Seoul city. The results were divided into two parts: (1) descriptive results of recognition and attitude toward air environment, (2) results of factor analysis to classify categories of attitudes toward air environment and regression analysis to identify factors affecting attitude toward air environment. Most of resident in Seoul city recognized that air environment in Seoul city was highly polluted and was not satisfactory. Experience of damage of air pollution was reported in about 70% of residents in Seoul city. More than 60% of residents in Seoul city had concern about air environment. Attitude toward air environment were classified into four categories using factor analysis: Necessity of intervention of local government for air environment conservation, Participation of residents and enterprises for air environment conservation, Optimistic attitude about air pollution, Preference of economy. Factors affecting the above attitudes were knowledge about air pollution, knowledge about policies and institutions related air environment conservation, concern about air environment, educational level, subjective assessment of air environment, sex, marital status. In conclusion this study suggested providing information of air environment in Seoul city to the residents and to educating residents for making positive attitude about air environment conservation.

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저수조 자동 분류를 이용한 효과적인 수질 오염 관리 (Effective Water Pollution Management using Reservoir Tank Automatic Classification)

  • 정경용;전인자
    • 한국콘텐츠학회논문지
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    • 제9권8호
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    • pp.1-8
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    • 2009
  • IT 융합 기술의 발전에 따라 정부의 4대강 복원을 위한 마스터플랜이 구축되면서, 환경 친화적인 수질 오염 관리의 중요성이 부각되고 있다. 본 논문에서는 친환경 저수조의 수질 향상과 온라인 관리를 하기 위해서 저수조 자동 분류를 이용한 효과적인 수질 오염 관리를 제안하였다. 제안된 방법에서는 수질오염 평가의 7가지 요소들을 정의하였고 센서를 이용하여 수소이온농도(pH), 화학적 산소요구량(COD),부유 물질량(SS), 용존 산소량(DO), 대장균군수(MPN), 총인 (T-P), 총질소(T-N)에 따른 적합한 수질 오염 관리를 하였다. 저수조의 7가지의 수질 오염 요소간의 측정치를 평가하고 [1,9] 사이에 분포하도록 정규화하였다. 저수조 자동 분류를 이용한 수질 오염 관리 시스템의 성능 평가를 하기 위해 F-측정식을 이용하여 유용성을 검증하였다. 평가 결과, 기존 시스템에 대한 만족도의 차이가 통계적으로 의미가 있음을 증명하였다.

이륜차의 일 주행거리조사와 대기오염 배출량 추정 (Estimation of Vehicle Kilometers Travelled and Air Pollution Emission from Motorcycles)

  • 장영기;김정;김필수;신용일;김운수;최유진
    • 한국대기환경학회지
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    • 제26권1호
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    • pp.48-56
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    • 2010
  • Recently it has reported that the motorcycle is a major source of air pollution in urban area by many studies. But the air pollution emission from motorcycle has been high uncertainty due investigation of a lack of activity data and emission factors in Korea. So in this study, the population of moped and VKT (Vehicle kilometers travelled) of motorcycle are investigated for calculation of the emission from this source categories. As the results, the population of moped is estimated as about 400, 000 and corresponded as 23% of registrated motorcycle which is larger than 50 cc in engine displacement. And it is found that the VKT of moped and motorcycle are investigated as 19.1 km/day and 32.3 km/day. Annual air pollution emission from motorcycle and moped are estimated by investigated VKT and updated emission factors. The nationwide emissions of PM_{10}, CO, $NO_x$, VOC are calculated as 910 ton/yr, 208, 198 ton/yr, 3, 032 ton/yr and 25, 575 ton/yr in 2008. The contribution ratio of CO, VOC emission from these sources are estimated as 29%, 24% in on-road transport sector and it is confirmed that motorcycle and moped are major air pollution sources in urban area.

대형배출원에서의 수은 측정방법 비교 및 배출계수 개발에 관한 연구 (A Study on the Comparison of Measuring Methods and Development of Emssion Factor on Mercury from Large-Scale Emission Sources)

  • 김형천;김록호;김종현;임승영;강대일;홍지형;장기원
    • 한국대기환경학회지
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    • 제32권2호
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    • pp.184-192
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    • 2016
  • Recently, studies on reducing mercury have been actively conducted worldwide, which include the current status of mercury emissions and mercury control technology. Among the control technology, Sorbent Trap measurement method has been aggressively developed due to its reliability, easiness in measurement and analysis. The purpose of this study is to evaluate the applicability of the new international measurement method; Sorbent Trap. For this, the study compared the Sorbent trap method (US EPA Method 30B) and the Korean Standard Method for Examination of Air (ES 01408.1) to evaluate their reliability, and developed mercury emission factors. As the result, the relative standard deviations (% RSD) of the two methods were 3.5~13.4% at Coal-fired Power Plants (CPP), 4.0~18.4% at Cement Kilns (CK), and 3.0~11.3% at Medical Waste Incinerators (MWI). The emissions factors were developed as 14.50 kg/ton at CPP, 45.10 kg/ton at CK, and 1,290.2 kg/ton at MWI.

Ambient air pollution and allergic diseases in children

  • Kim, Byoung-Ju;Hong, Soo-Jong
    • Clinical and Experimental Pediatrics
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    • 제55권6호
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    • pp.185-192
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    • 2012
  • The prevalence of allergic diseases has increased worldwide, a phenomenon that can be largely attributed to environmental effects. Among environmental factors, air pollution due to traffic is thought to be a major threat to childhood health. Residing near busy roadways is associated with increased asthma hospitalization, decreased lung function, and increased prevalence and severity of wheezing and allergic rhinitis. Recently, prospective cohort studies using more accurate measurements of individual exposure to air pollution have been conducted and have provided definitive evidence of the impact of air pollution on allergic diseases. Particulate matter and ground-level ozone are the most frequent air pollutants that cause harmful effects, and the mechanisms underlying these effects may be related to oxidative stress. The reactive oxidative species produced in response to air pollutants can overwhelm the redox system and damage the cell wall, lipids, proteins, and DNA, leading to airway inflammation and hyper-reactivity. Pollutants may also cause harmful effects via epigenetic mechanisms, which control the expression of genes without changing the DNA sequence itself. These mechanisms are likely to be a target for the prevention of allergies. Further studies are necessary to identify children at risk and understand how these mechanisms regulate gene-environment interactions. This review provides an update of the current understanding on the impact of air pollution on allergic diseases in children and facilitates the integration of issues regarding air pollution and allergies into pediatric practices, with the goal of improving pediatric health.

마산만 주변 해역에서 오염인자와 해양환경변동과의 관계 (Relationship between Pollution Factors and Environmental Variation in Waters around Masan Bay)

  • 신소영;이충일;황선출;조규대
    • 해양환경안전학회지
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    • 제10권2호
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    • pp.69-79
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    • 2004
  • 1981년부터 1998년까지 연구해역에서 COD와 DIP의 2월, 4월, 8월, 11월의 월별 분포양상은 비슷하였고, 두 항목 모두 8월에 가장 높은 값을 보인 반면 DIN의 경우는 2월, 4월, 8월, 11월로 갈수록 점차 증가하는 경향을 보였다. COD값은 1990년부터 1992년까지점차 증가하다가 1993년, 1994년으로 갈수록 감소하는 것을 볼 수 있는데, 이것은 마산만의 준설기간 중반부터 준설의 효과가 표층까지 나타난 것으로 보여진다. DIN과 DIP의 표층 농도 변화에는 준설의 효과가 뚜렷이 나타나지 않았다. COD의 공간적인 변동에서 적조가 빈발하였던 연도가 그렇지 않았던 연도에 비해 높은 COD농도의 분포가 마산만 밖으로 확장되어 있었고, 준설에 의한 COD값의 뚜렷한 변동은 나타나지 않았다. 전체적으로 DIN농도의 공간적인 분포 양상을 살펴보면 마산만의 안쪽에서부터 바깥쪽으로 오염이 점차 확장되었다. 마산만의 가장 안쪽 지점이 일정한 경향이 없이 높은 DIN농도를 유지하였으며, 내만 유역에 마산만의 오염원이 집중되어 있고, 마산만 유역에서 생활하수 및 산업폐수가 계속적으로 유입되고 있었다. DIP농도의 공간적인 분포에서도 마산만 준설이 DIP의 표층 농도 변화에는 뚜렷한 영향을 미치지 않은 것으로 나타났다. 강수량과 COD, DIN, DIP 농도 사이에는 일정한 상관성이 없었으며, 적조발생일수와 COD 농도 사이에는 0.66의 대체로 높은 상관성을 나타내었다.

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환경보전에 관한 인지와 관리행동 -대도시, 중 소도시, 군 단위 주부를 중심으로 (The Perception and the Management Behavior on the Enviornmental Preservation-focused on the housewives in the metropolitan, small city and kun-)

  • 오연옥
    • 대한가정학회지
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    • 제33권1호
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    • pp.45-60
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    • 1995
  • The purpose of this study is to investigate some influencing factors related to the perception and the management behavior on the environmental pollution of the housewives in the metropolis. small city and Kun. This study is also to provide some knowledge and information on the environmental preservation. 2300 questionaires were distributed to the housewives from the end of April to the end of May in 1994. The 1850 quentionaires were obtained and the 1490 data were analyzed by frequency, percentage, mean, t-test, F-test, Duncan's prohoc test, stepwise multiple regression, path analysis and pearson's correlation. The most hypotheses of this study were accepted. Based on the findings of this study, the degree of concerns on the environmental provlems, the enviromental education, the einvironmental articles and the paticipation of the environmental events were the most important factors on the knowledge of the environmental preservation and the perception of the environmental pollution. And these factors were exerted important effects on the management behavior on the environmental preservation.

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