Journal of Korean Society of Water and Wastewater (상하수도학회지)

The Korean Society of Water and Wastewater (대한상하수도학회)
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A Pilot Study on Air Flotation Processes for Retrofitting of Conventional Wastewater Treatment Facilities

하수처리시설의 Retrofitting을 위한 파일럿 규모 공기부상공정 연구

  • 박찬혁 (한국과학기술연구원 환경기술연구단) ;
  • 홍석원 (한국과학기술연구원 환경기술연구단) ;
  • 이상협 (한국과학기술연구원 환경기술연구단) ;
  • 최용수 (한국과학기술연구원 환경기술연구단)
  • Received : 2008.05.20
  • Accepted : 2008.06.05
  • Published : 2008.06.15
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Abstract

The pilot study was conducted to evaluate the applicability of air flotation(AF) processes combined with biological nutrient removal(BNR) for the retrofitting of conventional wastewater treatment facilities. The BNR system was operated in pre-denitrification and intermittent aeration; developed ceramic membrane diffusers were installed to separate the solid-liquid of activated sludge at the bottom of a flotation tank. Before performing a pilot scale study, the size distribution of microbubbles generated by silica or alumina-based ceramic membrane diffusers was tested to identify the ability of solid-liquid separation. According to the experimental results, the separation and thickening efficiency of the alumina-based ceramic membrane diffuser was higher than the silica-based ceramic membrane diffuser. In a $100m^3/d$ pilot plant, thickened and return sludge concentration was measured to be higher than 15,000mg SS/L, therefore, the MLSS in the bioreactor was maintained at over 3,000mg SS/L. The effluent quality of the AF-BNR process was 4.2mg/L, 3.7mg/L, 10.6mg/L and 1.6mg/L for $BOD_5$, SS, T-N and T-P, respectively. Lastly, it was revealed that the unit treatment cost by flotation process is lower than about $1won/m^3$ compared to a gravity sedimentation process.

Keywords

Acknowledgement

Supported by : 수처리선진화사업단

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