Journal of Korean Society of Water and Wastewater (상하수도학회지)

The Korean Society of Water and Wastewater (대한상하수도학회)
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Evaluation on Flotation Efficiency of Bubble-floc Agglomerates and Operation Characteristics of Hydraulic Loading Rate Using Population Balance in DAF Process

DAF공정에서 개체군 수지를 이용한 기포-플록 응집체의 부상효율과 수리학적 부하율의 운전특성 평가

  • 곽동희 (서남대학교 환경공학과)
  • Received : 2008.02.04
  • Accepted : 2008.10.08
  • Published : 2008.10.15
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Abstract

The main advantage of dissolved air flotation (DAF) in water treatment process is the small dimension compared with conventional gravity sedimentation and it can be basically reduced by the separation zone performed with the short solid-liquid separation time. Fine bubbles make such a short time possible to carry out solid from liquid separation as a collector on the course of water treatment. Therefore, the dimension of separation zone in DAF process is practically determined by the rise velocity of the bubble-floc agglomerates, which is a floc attached with several bubbles. To improve flotation velocity and particle removal efficiency in DAF process, many researchers have tried to attach bubbles as much as possible to flocs. Therefore, the maximum number of attached bubble on a floc and the rise velocity of bubble-floc agglomerates considered as the most important factor to design the separation zone of flotation tank in DAF process was simulated based on the population balance theory. According to the simulation results of this study, the size and volume concentration of bubble influenced on the possible number of attached bubble on a floc. The agglomerates attached with smaller bubble was more sensitive to hydraulic loading rate in the separation zone of DAF process. For the design of a high rate DAF process applied over surface loading 40 m/hr. it is required a precise further study on the variation of bubble property and behavior including in terms of bubble size distribution.

Keywords

Acknowledgement

Supported by : 한국과학재단

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