• Title/Summary/Keyword: contamination potential

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Field Investigation for Identification of Contamination Sources in Petroleum-Contaminated Site (유류로 오염된 부지의 원인자 판단을 위한 현장조사 평가)

  • Park, Jeong Jun;Kim, Sung Hwan
    • Journal of the Society of Disaster Information
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    • v.14 no.2
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    • pp.141-153
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    • 2018
  • Purpose : The subject site selected in this study was a place that was prepared through the reclamation of foreshore completed in 1973. Since then, the site has been occupied by the industry of ship repair for over 30 years. Method : The results of a precise soil examination conducted in 2013 showed that the site was seriously contaminated with TPH over an area of $10,000m^2$ and GL(-)3.0m in depth, with an expanding coverage of contamination. Results : The soil contamination by refined petroleum products often results in adverse effects to human health and ecological systems, thus the contamination should be purified as soon as possible. Conclusion : Hydrogeological investigation can be employed to assess the groundwater movement and propagation of contamination to determine the potential agents or contaminants in the soil contaminated with high concentration TPH.

Practical Radiation Safety Control: (I) Application of Annual Limit on Intake and Derived Air Concentration (방사선안전관리 실무: (I) 연간섭취한도와 유도공기중농도의 적용)

  • Kim, Hyun Kee
    • Journal of Radiation Protection and Research
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    • v.38 no.4
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    • pp.234-236
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    • 2013
  • Some of radioactive contamination is unavoidable in the facilities using the unsealed radioactive material. The primary purpose of radioactive contamination control in the workplace with contamination concern is the effects from the potential intake of radioactive material into the body. This paper provides procedures to estimate the level of internal exposure for the worker based on the conservative assumptions and simple calculations. They consist of two processes; to calculate air concentration of radioactive material and annual intake by inhalation with contaminated air and to compare each of them to Derived Air Concentration and Annual Limit on Intake mentioned in the related notification. The procedures are applicable to make a decision on practical requirements for monitoring air contamination and internal exposure of worker as follows; needs for measurement of air contamination and internal exposure and acquisition of information on the design of the ventilation system.

Applicability of Resistivity/Capacitance Measurement on CPT Module for Investigation of Subsurface Contamination (지반 오염도 조사를 위한 전기비저항/정전용량 측정콘의 적용성 평가)

  • Oh, Myoung-Hak;Kim, Yong-Sung;Park, Jun-Boum
    • Journal of the Korean Geotechnical Society
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    • v.22 no.7
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    • pp.45-54
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    • 2006
  • Resistivity cone penetrometer test (RCPT) can be employed at a relatively low cost for in-situ delineation of subsurface contamination. While the resistivity measurement has a potential to investigate the subsurface contamination, resistivity measurements alone will lead to some degree of ambiguity in the results. In this study, capacitance measurement was incorporated into the RCPT to overcome the ambiguity inherent in electrical resistivity measurements. This study is focused on verifying the applicability of resistivity and capacitance measurements of CPT module to provide information on subsurface contaminated by heavy metal and petroleum hydrocarbon. Laboratory model tests were performed to evaluate the sensitivity of the measured resistivity and relative capacitance on the water content and different types of contaminants. Test results show that simultaneous measurement of electrical resistivity and capacitance can give more reliable information on subsurface contamination. Electrical measurements of the CPT module showed high applicability to be used in detecting saturated soils contaminated by heavy metal and diesel plume floating above the groundwater table.

Climate change and resilience of biocontrol agents for mycotoxin control

  • Magan, Naresh;Medina, Angel
    • 한국균학회소식:학술대회논문집
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    • 2018.05a
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    • pp.41-41
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    • 2018
  • There has been an impetus in the development of biocontrol agents (BCAs) with the removal of a number of chemical compounds in the market, especially in the European Union. This has been a major driver in the development of Integrated Pest Management systems (IPM) for both pest and disease control. For control of mycotoxigenic fungi, there is interest in both control of colonization and more importantly toxin contamination of staple food commodities. Thus the relative inoculum potential of biocontrol agent vs the toxigenic specie sis important. The major bottlenecks in the production and development of formulations of biocontrol agents are the resilience of the strains, inoculum quality and formulation with effective field efficacy. It was recently been shown for mycotoxigenic fungi such as Aspergillus flavus, under extreme climate change conditions, growth is not affected although there may be a stimulation of aflatoxin production. Thus, the development of resilient biocontrol strains which can may have conserved control efficacy but have the necessary resilience becomes critical form a food security point of view. Indeed, under predicted climate change scenarios the diversity of pests and fungal diseases are expected to have profound impacts on food security. Thus, when examining the identification of potential biocontrol strains, production and formulation it is critical that the resilience to CC environmental factors are included and quantified. The problems in relation to the physiological competence and the relative humidity range over which efficacy can occur, especially pre-harvest may be increase under climate change conditions. We have examined the efficacy of atoxigenic strains of A. flavus and Clanostachys rosea and other candidates for control of A. flavus and aflatoxin contamination of maize, and for Fusarium verticillioides and fumonisin toxin control. We have also examined the potential use of fluidized-bed drying, nanoparticles/nanospheres and encapsulation approaches to enhance the potential for the production of resilient biocontrol formulations. The objective being the delivery of biocontrol efficacy under extreme interacting climatic conditions. The potential impact of climate change factors on the efficacy of biocontrol of fungal diseases and mycotoxins are discussed.

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Cation Exchange Capacity and Zeta Potential Characteristics of Kaolinite Contaminated with Lead (납으로 오염된 카올리나이트의 양이온교환능력 및 계면동전위 특성)

  • 장경수;강병희
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2002.04a
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    • pp.38-43
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    • 2002
  • A series of tests were performed to investigate the effects of pH and contamination level on cation exchange capacity and zeta potential in kaolinite loaded with lead. Test results show that cation exchange capacity of kaolinite is found to be in the range from 4 to 20meq/100g and it increased with increasing pH up to the converged number about 20meq/100g over pH 8. And then CEC has a tendency to reduce and converge to zero with increasing the concentration of Pb in the kaolinite surface. Moreover, zeta potential of kaolinite contaminated with lead is found to be in the range from -10 to 5mV, and zero point of charge is measured at about pH 3.5. Zeta potential of kaolinite contaminated with lead decreases with increasing pH values and decreasing Pb concentration of kaolinite.

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Minimization of Asymmetry Potential in ETH 129-Based Calcium-Selective Membrane Electrodes

  • 박성배;정사라;차근식;김해동
    • Bulletin of the Korean Chemical Society
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    • v.16 no.11
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    • pp.1033-1037
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    • 1995
  • PVC-based calcium-selective electrodes doped with ETH 129 usually suffer from a shift in the standard potential when they are in contact with protein-containing solutions (e.g. blood serum) after being calibrated with aqueous standards. The shift is due to the development of asymmetry potential in inherently symmetric PVC membranes through the contamination of outer membrane surface by proteins in the biological samples. Membranes prepared with polyurethane showed much reduced shifts in terms of standard potential. This study was performed with a flow-injection system following a protocol designed to observe minor shifts in baseline potential. Other electrochemical properties of the system, including selectivity and response slope, were similar to those obtained with regular PVC-based ones. PVC-based calcium selective membrane electrodes, doped with commonly used ETH 1001, were also tested to compare their electrochemical performances.

Hydrochemical Characteristics of Groundwater in an Area Affected by Pig Carcass Burial: Leakage Detection (돼지사체 매몰지역 지하수의 수지구화학 특성: 침출수 누출 판단)

  • Oh, Junseop;Kim, Ho-rim;Lee, Jeong-Ho;Kim, Kyoung-ho;Choi, Kwang-jun;Kim, Hyeon-Koo;Yun, Seong-Taek
    • Journal of Soil and Groundwater Environment
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    • v.23 no.1
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    • pp.30-40
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    • 2018
  • To evaluate potential impacts of shallow groundwater by the leachate from buried carcass, we investigated hydrochemical characteristics of both leachate and shallow groundwater from monitoring wells and surrounding shallow groundwater wells in an area potentially affected by pig carcass burial. The hydrochemical survey was conducted before and after the relocation of a burial pit. The leachate samples and the groundwater affected by leachate showed the hydrochemistry of $Ca-HCO_3$ type with high $NH_4{^+}$ concentrations, while unaffected groundwater was mostly the $Ca(Na)-Cl+NO_3$ type due to pervasive impacts from agrochemicals. The results of factor analysis on hydrochemical data showed the followings: 1) contamination of groundwater from agro-livestock farming and livestock burial are coexisting in the study area, 2) among ionic species, $HCO_3{^-}$, $NH_4{^+}$, $NO_3{^-}$ and Mn are very useful to differentiate the groundwater contamination from leachate, and 3) groundwater contamination by leachate has been recognized around the monitoring wells even after the relocation of a burial pit, likely due to residual contaminants in surrounding soils. Therefore, it is suggested that continued monitoring of groundwater contamination should be conducted after the relocation of carcass burial pits.

A Comparison of Microbial Load on Bare and Gloved Hands among Food Handlers (맨손과 장갑 낀 손의 미생물 오염도 비교)

  • Kim, Jong-Gyu;Park, Jeong-Yeong;Kim, Joong-Soon
    • Journal of Environmental Health Sciences
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    • v.37 no.4
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    • pp.298-305
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    • 2011
  • Objectives: There has been a great amount of controversy in the food industry over the effectiveness of using gloves. The objectives of this study were to examine the microbial contamination of food handlers' hands and determine if using gloves could ensure safe handling of foods. Methods: Samples were collected through the glove-juice method from the bare and gloved hands of food handlers at work and were analyzed for the presence of aerobic plate counts, total coliform, fecal coliform, Escherichiacoli, Staphylococcus aureus, and Salmonella spp. Microbiological testing was conducted according to the Food Code of Korea. Results: Microbial contamination was consistently higher with bare hands than with gloved hands, although the microbial loads on both hands increased over time. Under certain conditions, there were significant differences between the bacterial loads on bare and on gloved hands (p<0.05). E. coli, S. aureus, and Salmonella spp. were still alive on both bare and gloved hands at the time the food handlers finished their work. Conclusions: Wearing gloves was associated with a marked reduction of bacterial contamination of the hands. However, the practice of continuously wearing gloves during food handling increases the potential for cross-contamination of bacteria. The findings of this study emphasize the need for a rational use of gloves, and strict adherence to hand hygiene compliance among food handlers.