• 제목/요약/키워드: Density of Odor

검색결과 46건 처리시간 0.02초

전해 산화제에 의한 악취 원인 VOCs 제거 특성 (Characteristics of odorous VOCs removal by using electrolytic oxidant)

  • 이태호;류희욱
    • 실내환경 및 냄새 학회지
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    • 제17권4호
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    • pp.381-388
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    • 2018
  • In this study, various conditions and phenomena that occur in the process of removing odorous VOCs by using electrolyzed oxidant were examined. The formation of hypochlorous acid, which is an oxidant produced by electrolysis, was investigated and the properties of the oxidizing agent used to decompose toluene, xylene, and cyclohexane were investigated. As a result, it was found that the production rate and the final concentration of the oxidizing agent increased with the current density. It was found that the degree of removal varies depending on the property of each pollutant. Interestingly, in the batch experiments in which the pH of the produced oxidant was controlled, it was found that the degree of elimination varied depending on the pH of the substance. These results suggest that the difference in the concentration and distribution of hypochlorous acid (HOCl) and hypochlorite ($OCl^-$) due to the pH change leads to the difference in oxidizing power on the oxidation characteristics of each substance. Styrene and terpineol showed better degradation characteristics than toluene and xylene in odorous VOC removal experiments by spraying electrolytic oxidant using a lab-scale continuous reactor. In conclusion, the removal of odorous VOCs by the electrolytic oxidant can have various applications in that it can oxidize pollutants of various spectra.

조류와 유기화합물의 동시제거를 위한 흡착 - DAF 복합공정 (Adsorption-DAF Hybrid Process for the Simultaneous Removal of Algae and Organic Compounds)

  • 이재욱;곽동희;최승필;정흥조
    • 상하수도학회지
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    • 제18권2호
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    • pp.208-214
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    • 2004
  • Dissolved air flotation (DAF) is an effective solid/liquid separation process for low density floc particles such as algal, color-alum and clay-alum flocs produced from low turbidity water. The removal of taste and odor-causing organics (2-mthylisoboneol and geosmin) originating from algae in drinking water is a local and worldwide concern. Although DAF has been effectively applied for the removal of suspended solid, its application for the treatment of dissolved organic carbon is very limited. In this study, a new hybrid system consisting of adsorption and DAF processes was introduced for the simultaneous removal of algae and taste and odor-causing organics. Powdered activated carbon (PAC) was used as an adsorbent. In this proposed system, the major concern of eliminating the spent PAC from the system was also addressed. It was found that zeta potential of algae and PAC was increased with coagulant dosage, and the removal efficiency in DAF was also enhanced up to 90~95% under the given experimental conditions. Based on this study, the hybrid process was found to be a promising technology for the simultaneous removal of algae and dissolved organic pollutants.

백로번식지 주변 개발사업의 환경영향평가시 중점평가항목 선정 및 평가방안 연구 (A Study on the Determination of Major Evaluation Items and the Preparation of Report when Evaluating the Environmental Impact of Development Projects around Ardeidae Breeding Habitats)

  • 임혜령;김선구
    • 환경영향평가
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    • 제32권1호
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    • pp.1-14
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    • 2023
  • 백로번식지 주변 개발사업을 진행할 때 환경영향평가 단계에서 갈등을 사전에 예방할 수 있도록 중점평가항목 선정과 저감방안을 제시하여 지속가능한 공존의 방안을 강구하고자 한다. 중점평가항목으로 백로번식지 보전을 위한 동·식물상 항목, 백로번식지로 인한 악취와 소음의 영향을 평가할 수 있는 악취와 소음 항목을 선정한다. 평가항목의 평가방안은 첫째, 동·식물상 항목에서 조사범위는 법정보호종 위주로 국한하지 말고 주요 종 번식지와 철새도래지에 해당하는 백로번식지와 취식지까지 포함하여 조사하고, 번식지와 취식지 면적감소에 따른 보전방안을 세운다. 둘째, 악취 항목에서 조사시기는 6월말에서 7월말까지 악취발생량이 최고인 시점을 포함한다. 악취 평가기준은 농도규제인 복합악취 배출허용기준과 사람이 느끼는 악취농도는 2~5OU/m3, 빈도는 2% 이하로 한다. 셋째, 소음 항목에서 조사시기는 백로류와 어린 새들의 소리가 합해져서 소음 발생이 최대가 되는 시점을 포함하여 5월부터 8월까지 매달 소음을 측정한다. 여름철새인 백로류의 소음은 일정 기간에만 발생하기 때문에 방음벽 설치 등 인공적인 구조물 설치로 소음을 저감하기 보다는 이격거리확보, 완충녹지, 마운딩 조성 등의 방법으로 저감대책을 세운다. 기존 백로번식지가 개체군의 적정한 밀도를 유지하면서 개체군이 다른 곳으로 이동하지 않기 위해서는 영소목 관리와 취식지의 양과 질을 안정적으로 유지해주는 것이 선행되어야 한다.

잣나무 소경재의 재질평가를 통한 실내장식용재 개발 (A Development of Interior Decoration Timber with Pinus koraiensis Small Diameter Logs)

  • 박병호;김남훈
    • Journal of Forest and Environmental Science
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    • 제28권4호
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    • pp.268-277
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    • 2012
  • Among the domestic softwoods, technical value of Pinus koraiensis small diameter logs which have comparatively low applicability was evaluated and sensitive characteristics and physical characteristics were investigated and analyzed for examining if it can be utilized as the interior decoration material. For the sensitive characteristics of Pinus koraiensis, wood figure, wood grain, wood color and odor were evaluated and for the physical characteristics, growth-ring width and latewood percentage, abrasion, density, shrinkage, swelling, absorption, roughness and hardness were evaluated. Then, the possibility to be developed as the interior decoration material was found. As the result of evaluating sensitive characteristics and physical characteristics of domestic Pinus koraiensis, wood figure, wood grain, color and scent clearly were judged to have excellent visual factor as the interior decoration material. And, physical characteristics were also judged to be excellent, so it is judged to be developed as the interior decoration material. Therefore, as the result of various forms of design pattern with domestic Pinus koraiensis small diameter logs, several patterns of interior decoration can be developed by characteristics of each side and colors of heartwood and sapwood. And, in the future, it can be applied to furniture design or interior decoration material for the proper use. Especially, it is considered to contribute to wood applying industry through the study on the quality of domestic small diameter logs which have low applicability.

랩-베일을 이용한 양돈용 TMR 발효사료 제조 시스템 개발 (Development of a Fermented TMR for Pigs Using Bale-Wrapping System)

  • 김혁주;유병기;이성현;유지수;서형덕
    • 한국축산시설환경학회지
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    • 제20권3호
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    • pp.105-116
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    • 2014
  • In this study, we developed a fermented TMR producing system which could a continuous operation of baling and wrapping the mixed TMR. The baling part has fixed chamber of dia. 900 mm and width 900 mm. And the the turn-table type wrapping part is very compact compared to conventional one in market. The test result were: The absorbed power of the prototype in working was 9.0~15.7 kW. The combined baling and wrapping performance was over 20 bales/hr. The leakage in the process was around 1.9 kg for making a 350 kg TMR bale. The diameter of wrapped TMR bale was 900~950 mm, and its weight was 350 kg in average. Therefore the density was $718kg/m^3$, and it was very high density to the inputted TMR. The pH of the fermented TMR was 5.0~5.6 which was similar to the fermented haylage, also the TMR had no butyric acid's odor.

활성탄 재생이 자연유기물질의 흡착에 미치는 영향 (Effect of Reactivation of Activated Carbon on Adsorption of Natural Organic Matter)

  • 홍성호;최주솔
    • 상하수도학회지
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    • 제21권3호
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    • pp.323-329
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    • 2007
  • There is no certain definition about advanced drinking water treatment but it is generally known as activated carbon process, membrane process or ozone process which can remove non-conventional pollutants such as taste and odor compounds, and micro-pollutants. There are more than 20 processes related to activated carbon as adsorber or biological activated carbon in Korea. The saturated carbon by pollutants can be reused by reactivation. However, the effect of reactivation on activated carbon is not well-understood in terms of changing physical properties of carbon to adsorption capacity of natural organic matter (NOM). In this study, the effects of reactivation on physical properties of activated carbon were investigated by isotherm and breakthrough of NOM. Ash content was increased from 8% to 13.3%. Iodine number is commonly used as an indicator for performance of reactivation. The iodine number was decreased about 20% after reactivating twice. The degree of reactivation can be evaluated by not only iodine number but also apparent density.

키토산 청국장을 첨가하여 제조한 깊펠 쿠키의 품질 특성 (Quality Characteristics of Kipfel Cookie Prepared with Chitosan-Chungkukjang)

  • 이예경;김미정;이승배;김순동
    • 동아시아식생활학회지
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    • 제15권4호
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    • pp.437-443
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    • 2005
  • Quality characteristic of Kipfel cookies with 0, 20, 40 and $60\%$ of freeze dried chitosan-chungkukjang(CC), which was fermented for 24 hours at $40^{\circ}C$ with steamed soybean added with $0.25\%$ of chitosan(MW 2,025 kDa) powder and inoculated $2\%$ of Bacillus lichenifomis, were investigated Bulk density was higher in the CC cookie, but there were no difference among the CC cookies. While hardness was decreased, brittleness and springiness were increased in the higher ratio of CC, but no significant difference was observed in cohesiveness and gumminess. According to increasing the CC ratio, L$\ast$ values and hue angle were decreased from 62.69 and 96.71 to 44.41 and 69.30, respectively. While a$\ast$ values were increased from -1.94 to 4.95, and no changes were observed in b$\ast$ values. Glucosamine content was $27.34 mg\%$ in the control cookie, $40{\~}93.75 mg\%$ in the CC cookies. Antioxidant activity of the CC cookies were higher than the control. The activity of the control cookie was decreased during storage, while it was maintained in CC cookies. There were no differences in the sour, sweet and savory taste. Off-flavor did not detected in the $0{\~}40\%$ CC cookies, but the chungkukjang odor was slightly detected in the $60\%$ CC cookie. The $20{\~}40\%$ CC cookies did not affect on native odor of Kipfel cookie. Color acceptability also did not affect by addition of CC $20{\~}40\%$ but it was lower in $60\%$ CC cookie. Overall acceptability was the best in the $20\%$ CC cookie.

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오이풀 첨가 쿠키의 특성연구 (The Quality Characteristics of Cookies containing of Powder Sanguisorba officinalis L.)

  • 이선호
    • 한국조리학회지
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    • 제23권4호
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    • pp.74-80
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    • 2017
  • This study was to investigate the physiological activity of cookies with Sanguisorba officinalis L. powder. Our results showed that the pH of the cookies ranged from 6.34 to 6.29, and the density ranged from 4.12 to 4.40. Increasing the amount of Sanguisorba officinalis L. powder in the cookies decreased the spread factor of the cookies and tended to decrease lightness (L) in the Hunter color value with yellowness (b) and redness (a) increased. For the textural characteristics, the addition of Sanguisorba officinalis L. powder increased hardness. The sensory evaluation showed that the cookies with Sanguisorba officinalis L. powder were preferred more than those without in color, odor, texture, taste and overall preference. Based on the results above, the cookies that contained 3% of Sanguisorba officinalis L. powder presented the best quality.

A Comparative Study on the Aerobic Biodegradation of the Continuous and Intermittent Aeration in Bin Composting System

  • Hong, Ji-Hyung;Choi, Byoung-Min;Park, Keum-Joo
    • 한국농공학회지
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    • 제42권
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    • pp.61-67
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    • 2000
  • Composting of hog manure amended with sawdust trials lasted three weeks and used pilot-scale in bin composting system. Results showed that the rise temperature and carbon dioxide evolution in compost during the composting decomposition process were affected by the aeration method, pH, C/N, moisture content, bulk density and particle size distribution. No significant differences existed in biophysical properties of the composit produced from the continuous and intermittent aeration method. The intermittent aeration was very successful in compost odor control and required less time to reach stability than the continuous aeration.

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개에서 컴퓨터 단층촬영상을 통한 중이염의 진단 (Radiographic and CT Diagnosis Of Otitis Media In a Dog)

  • 이기창;서은정;권정국;송경진;윤정희;최민철
    • 한국임상수의학회지
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    • 제21권2호
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    • pp.184-186
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    • 2004
  • A castrated male, 6 year-old Shih-Tzu, weighing 4.6 kg with a discharge from the external ear canal and a mal-odor was referred to Verterinary Medical Teaching Hospital, Seoul National University. Radiographic findings were narrowing and focal loss of an air density in the left ear canal and bilateral thickening of the osseous bullae. For more detail examination, computed tomography was used. In computed tomographic findings, bilateral thickening of the bulla wall and increased opacity of the bulla space were observed. Thus this dog was diagnosed as bilateral otitis media. Then surgical correction, total ear canal ablation, was performed successfully and the patient showed a good prognosis thereafter. It is considered that computed tomography might serve as an useful imaging tool for otitis media and that it supplies information not obtained with a conventional radiography.