• 제목/요약/키워드: shear stres

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Relationship among Physical & Chemical Properties of Supports and Performance of Methane Fermentation in Anaerobic Fluidized-Bed Reactor (혐기성 유동층 반응기에서 지지체의 물리.화학적 특성과 메탄 발효 성능 사이의 관계)

  • 조무환;남영섭정재학김정목
    • KSBB Journal
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    • v.8 no.5
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    • pp.431-437
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    • 1993
  • Active carbon which has the smallest bulk and wet density was found as the best support media among 4 different kinds of materials(celite, natural zeolite, Pusuk stone, active carbon) to make a proper fluidized-bed with small energy consumption. Its minimum and optimum fluidization velocity were found as 0.03cm/sec and 0.25cm/sec, respectively. As organic loading rate for methane fermentation was increased, CODcr removal efficiencies of all the media were decreased. But, CODcr, removal efficiencies of active carbon was maintained more than 90% in this experimental range of the organic loading rate. Larger amount of microorganism was adsorbed on the active carbon which has very high specific surface area. At the organic loading rate of 16g CODcr,/l day, its adsorbed cell mass was 157mg/g. Comparing natural zeolite with roast celite, adsorbed cell mass did not increase in proportion to specific surface area of the media. Even though roast celite has the same specific surface area as the Pusuk stone, its organic removal ability was superior to that of the Pusuk stone, which explains that the relatively great surface roughness and the positive surface charge are important for cell adsorption. It was concluded that the support media for anaerobic fluidized reactor should have small wet density and small fuidization velocity, if possible, in order to increase cell adsorption by reducing the fluid shear stress.

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Removal of Ammonia-N by using the Immobilized Nitrifier Consortium in Aquaculture System (양어장에서 고정화된 질화세균군을 이용한 암모니아 질소 제거)

  • SUH Kuen-Hack;KIM Yong-Ha;AHN Kab-Hwan
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.30 no.5
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    • pp.868-873
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    • 1997
  • Nitrifier consortium entrapped in Ca and Ba-alginate beads were packed into two reactors and studied for removing ammonia-nitrogen in aquaculture system. The ammonia-nitrogen concentration of the influent was continually kept about 2 ppm. At the hydraulic residence time of 0.6 hours, ammonia-nitrogen removal amount of two reactors was about 52.6 and 51.0 g $NH_3-N/m^3/day$, respectively. The ability of adjusting to an impulsive leading which was happened according to variations of HRT was better at Ba-alginate reactor, but its discrepancy was not so large. At the respect of removing ammonium-nitrogen, two reactors showed the similar ability of treating recirculating water.

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