• 제목/요약/키워드: technology and environment

검색결과 23,275건 처리시간 0.054초

마을단위 소규모 하·폐수처리 공정의 효율적 유지관리를 위한 전문가 시스템에 관한 연구 (An Innovative Expert System for the Maintenance of On-site Wastewater Treatment Process for Small-scale Residential and Commercial Sites)

  • 김승준;최용수;홍석원;권기한;정익재
    • 한국물환경학회지
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    • 제21권2호
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    • pp.132-140
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    • 2005
  • The pilot test of a new alternative for small wastewater treatment system has been conducted for two years. It consists of a hybrid bioreactor and the expert system including the process control logic, PLC system, and HMI for the process automation. In order to monitor and remote control its status, the real-time data was transferred from the on-site control center to the central station via a wireless local area network. More efficient and stable performances were observed at automatic operating mode compared with the manual. On an average, COD, SS, T-N and T-P concentrations in the effluent from the hybrid bioreactor were less than 14, 7, 12 and 0.9 mg/L, respectively. According to the result from pilot tests, the quality of treated wastewater with sand filtration was enough to be utilized again.

충청도 내 일반국도 절토사면의 현황자료와 위험도간의 상관성분석 (Correlation Analysis between Inventory data and danger grade of Cut slope in Chungcheongdo)

  • 김진환;이종현;김승현;이정엽;구호본
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2008년도 추계 학술발표회
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    • pp.980-983
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    • 2008
  • KICT has been carrying out inventory research on the cut slopes of national roads. Inventory research results are basic data used in cut slope management system. Inventory data are classified by general status, cut slope characteristics and inspector opinion. Cut slope inventory data are utilized to figure out dangerous slopes and decide survey ranking of detailed safety diagnostication. This paper will draw dangerous cut slope and more important inventory data in Chungcheongdo via correlation analysis.

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On-Line Monitoring of Low Biochemical Oxygen Demand Through Continuous Operation of a Mediator-Less Microbial Fuel Cell

  • MOON, HYUN-SOO;CHANG, IN-SEO;JANG, JAE-KYUNG;KIM, KYUNG-SHIK;LEE, JI-YOUNG;LOVITT, ROBERT W.;KIM, BYUNG-HONG
    • Journal of Microbiology and Biotechnology
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    • 제15권1호
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    • pp.192-196
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    • 2005
  • Abstract Oligotrophic microbial fuel cells (MFCs) were tested for the continuous monitoring of low biochemical oxygen demand (BOD) by using artificial wastewater, containing glucose and glutamate, as check solution. Ten times diluted trace mineral solution was used to minimize the background current level, which is generated from the oxidation of nitrilotriacetate used as a chelating agent. The feeding rate of 0.53 ml/min could increase the sensitivity from 0.16 to 0.43 ${\mu}$A/(mg BOD/l) at 0.15 ml/min. The dynamic linear range of the calibration curve was between 2.0 and 10.0 mg BOD/l, and the response time to the change of 2 mg BOD/l was about 60 min. The current signal from an oligotroph-type MFCs increased with the increase in salts concentration, and the salt effect could be eliminated by 50 mM phosphate buffer.

바이오필름 반응기상에서 수소 이용성 독립영양생물을 이용한 고농도 탈질 반응 (Autohydrogenotrophic Denitrification of High Nitrate Concentration in a Glass Bead Biofilm Reactor)

  • 박호일;김지성;김동건;박대원
    • 한국물환경학회지
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    • 제20권3호
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    • pp.236-240
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    • 2004
  • Autohydrogenotrophic denitrification of high nitrate concentration contaminated wastewater in a batch-scale biofilm reactor has been investigated. High nitrate concentration decreased as pH increased from 7.01 to 9.45. The high nitrate concentrations continuously decrease from $150mg.l^{-1}$ to $0mg.l^{-1}$. Nitrite concentrations increase at about two-thirds way through the denitrification process and thereafter it decreases with time. Autohydrogenotrophic denitrification of high nitrate concentration is passible to use drinking water as well as wastewater, and to deal with wastewater treatment by hetrotrophic denitrification.

감마선 조사법을 이용한 전기방사 나노/마이크로 섬유 지지체의 표면 기능화 (Functionalization of Electrospun Nano/Micro-fibrous Scaffolds Using Gamma-ray Irradiation)

  • 임종영;신영민;최종배;정진오;권희정;정성린;박종석;임윤묵
    • 방사선산업학회지
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    • 제7권1호
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    • pp.45-49
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    • 2013
  • In tissue engineering application, a fibrous structure of scaffolds has been issued as an alternative system to regulate cell survival and tissue regeneration, and electrospinning technique has been popularly used to generate fibrous meshes or sheets mimicking the structure of native extracellular matrix (ECM). However, recent strategy in the scaffold development is expanded to provide the structural property as well as a biological property of native ECM, a variety of surface modification techniques have been used to introduce biological property. In this study, we developed biomimetic poly(L-lactide-co-${\varepsilon}$-caprolactone) (PLCL) nano- and micro-fibrous scaffolds as a unique platform with structural and biological properties with native ECM using electrospinning method and gamma-ray irradiation. Surface morphology of the scaffolds was observed by scanning electron microscopy, and alteration of surface property was evaluated with toluidine blue O staining, water contact angle measurement and ATR-FTIR analysis.

Numerical Modeling of the Effect of Sand Dam on Groundwater Flow

  • Yifru, Bisrat;Kim, Min-Gyu;Chang, Sun Woo;Lee, Jeongwoo;Chung, Il-Moon
    • 지질공학
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    • 제28권4호
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    • pp.529-540
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    • 2018
  • Sand dam is a flow barrier commonly built on small or medium size sandy rivers to accumulate sand and store excess water for later use or increase the water table. The effectiveness of sand dam in increasing the water table and the amount of extractable groundwater is tested using numerical models. Two models are developed to test the hypothesis. The first model is to simulate the groundwater flow in a pseudo-natural aquifer system with the hydraulically connected river. The second model, a modified version of the first model, is constructed with a sand dam, which raises the riverbed by 2 m. In both models, the effect of groundwater abstraction is tested by varying the pumping rate. As the model results show the groundwater after the construction of the sand dam has increased significantly and the amount of extractable groundwater is also increased by many folds. Most importantly, in the second model, unlike the pseudo-natural aquifer system, the groundwater abstraction does not have a significant effect on the water table.