• 제목/요약/키워드: Environmental science & technology

검색결과 9,804건 처리시간 0.037초

질소화합물(NH4+, NO3-)의 모니터링을 위한 마이크로 센서의 작동에 미치는 온도 영향 (The Effect of Temperature on Mlcrosensor Chip for the Monitoring of Nitrogenous Compounds(NH4+, NO3-))

  • 이종원;전경미;장암;유혜원;조재원;김인수
    • 한국물환경학회지
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    • 제23권1호
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    • pp.33-37
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    • 2007
  • Microelectrodes for measuring nitrogenous compounds (${NH_4}^+$, ${NO_3}^-$) that were applied into the microfluidics chips was investigated, and the effect of temperature was especially examined. In this specific research, microelectrodes were first calibrated to check the function, and then microsensor that was combined microelectrode with microfluidic chip was re-calibrated. Experimental results showed that there are no change in the function between microelectrode and microfluidic chip. The electro motive force (EMF) for the ${NH_4}^+$ microsensor was similar to the one theoretically calculated from Nernst equation, but the EMF for ${NO_3}^-$ showed minor change.

Power Density Enhancement of Anion-Exchange Membrane-Installed Microbial Fuel Cell Under Bicarbonate-Buffered Cathode Condition

  • Piao, Jingmei;An, Junyeong;Ha, Phuc Thi;Kim, Taeyoung;Jang, Jae Kyung;Moon3, Hyunsoo;Chang, In Seop
    • Journal of Microbiology and Biotechnology
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    • 제23권1호
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    • pp.36-39
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    • 2013
  • We introduce a high-performance microbial fuel cell (MFC) that was operated using a 0.1M bicarbonate buffer as the cathodic electrolyte. The MFC had a 136.42 $mW/m^2$ maximum power density under continuous feeding of 5 mM acetate as fuel. Results of the electrode potential measurements showed that the cathode potential of the bicarbonate-buffered condition was higher than the phosphate-buffered condition, although the phosphate condition had less interfacial resistance between the membrane and electrolyte. Therefore, we posit here that the increased power of the bicarbonate-buffered MFC may be caused by the higher cathode potential rather than by the interfacial membrane-electrolyte resistance.

Semi-interpenetrated Polymer Network of Sulfonated Poly(Styrene-Divinylbenzene-Acrylonitrile) based on PVC Film for Polymer Electrolyte Membranes

  • Yun, Sung-Hyun;Woo, Jung-Je;Seo, Seok-Jun;Park, Jung-Woo;Oh, Se-Hun;Moon, Seung-Hyeon
    • Korean Membrane Journal
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    • 제11권1호
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    • pp.8-14
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    • 2009
  • The sulfonated poly(styrene-divinylbenzene-acrylonitrile) (ST-DVB-AN) composite polymer electrolyte membrane based on the original PVC film was successfully synthesized to improve oxidative stability using semi-interpenetrated polymer network (semi-IPN). Weight gain ratio after copolymerization was enhanced by the DVB and AN contents, and the sulfonated membranes were characterized in terms of proton conductivity (k), ion exchange capacity (IEC), and water uptake ($W_U$). The effect of DVB content and AN addition were thoroughly investigated by comparing the resulted properties including oxidative stability. The obtained ST-DVB-AN composited semi-IPN membranes showed relatively high proton conductivity and IEC compared with Nafion117, and greatly improved oxidative stability of the synthesized membrane was obtained. This study demonstrated that a semi-interpenetrated sulfonated ST-DVB-AN composited membrane reinforced by PVC polymer network is a promising candidate as an inexpensive polymer electrolyte membrane for fuel cell applications.

RESEARCH PAPERS : THE KINETICS ON THE BIOLOGICAL REACTION IN MEMBRANE BIOREACTOR (MBR) WITH GRAVITATIONAL AND TRANSVERSAL FILTRATION

  • Jang, Nam-J.;Hwang, Moon-H.;Yeo, Young-H.;Shim, Wang-G.;S. Vigneswaran;Kim, In-S.
    • Environmental Engineering Research
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    • 제9권5호
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    • pp.238-247
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    • 2004
  • The objective of this study was to develop kinetic model for the MBR and investigate kinetic characteristics of the gravitational flow transverse direction MBR system. Kinetic model was derived by mass balance of substratc and biomass combined with empirical membranc filtration rerm for the MBR. To find kinctic values, permeale flux and COD removal were analyzed through the laboratory, MBR operation as different solids retention times. Permeate flux was ranged 2.5-5.0 LMH (L/m$^2$/hr) as sludge characteristics in each run. Although the soluble COD in the bioreactor was changed, the effluent COD was stable as average 99% removal rate during the experimental periods. Y$_g$ of this MBR system was higher than those of cross-flow MBR processes. The kinetics of this MBR showed that smaller k, larger b, and larger K$_s$ values than the conventional activated sludge process. These results indicated that substrate was used for cell maintenance rather than growth in this MBR system.