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KSCE Journal of Civil Engineering

, Volume 2, Issue 4, pp 461–466 | Cite as

Zeta potential measurement of bubbles in DAF process and its effect on the removal efficiency

  • Mooyoung Han
  • Seok Dockko
Environmental Engineering

Abstract

Dissolved Air Flotation (DAF) process has proved its efficiency in water treatment process and has gained much interest, however, the research to investigate the process from the fundamental characteristics of bubbles and particles has been limited.

In this research, the electrostatic nature of both bubble and particle/floc was focused. The zeta potential of bubbles is measured by a system composed of a measuring cell, microscope, video camera and a video image analyzer. The kaolin particle was measured by a commercial zeta meter. The zeta potential variation of bubbles and floc with pH are presented.

The effects of several operational parameters in DAF process are investigated on a batch DAF reactor, microscope and video system. The effect of pH on the removal efficiency of DAF is presented. The effect of mixing time is presented. The effect of zeta potential of floc and bubbles with the addition of coagulant is presented. It is found that all the phenomena can be explained primarily from the electrostatic nature of bubble and particle and secondarily from the effect of particle size.

The findings from this research will be helpful to understand and explain the process better and possibly can be used to modify and improve the DAF process. Dissolved air flotation, zeta potential, bubble, kaolin, removal efficiency, pH, mixing time.

Keywords

dissolved air flotation zeta potential bubble kaolin removal efficiency pH mixing time 

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References

  1. 1.
    Amirtharajah A, Mills K M (1982) Rapid mix design for mechanisms of alum coagulation.J. of AWWA 74 No. 4, pp. 210–217.Google Scholar
  2. 2.
    Fukushi K, Matsui Y, and Tambo N (1998) Dissolved air flotation: experiments and kinetic analysis.Aqua 47 No. 2, pp. 76–86.CrossRefGoogle Scholar
  3. 3.
    Han M Y, Dockko S, and Park C H (1997) Collision efficiency factor of bubble and particle in DAF.CIWEM London, pp. 409–416.Google Scholar
  4. 4.
    Kubota K, Jameson G J (1993) A study of the electrophoretic mobility of a very small inert gas bubble suspended in aqueous inorganic electrolytic and cationic surfactant solutions.J. of Chemical Eng. of Japan 26, No. 1, pp. 7–12.CrossRefGoogle Scholar
  5. 5.
    Okada K, Akagi Y (1987) Method and apparatus to measure the zeta potential of bubbles.J. Chem. Eng. of Japan 20, No. 1, pp. 11–15.CrossRefGoogle Scholar
  6. 6.
    Okada K, Akagi Y, Kogure M, Yoshioka N (1990) Analysis of small particles in flotation when the particles and bubbles are both charged.The Canadian J. of Chemical Engineering 68 pp. 393–399.CrossRefGoogle Scholar
  7. 7.
    Wiersema P H, Loeb A L, Overbeek J T G (1996) Calculation of the electrophoretic mobility of a spherical colloid particle.J. Colloid Interface Sci. 22, pp. 78–98.CrossRefGoogle Scholar

Copyright information

© KSCE and Springer jointly 1998

Authors and Affiliations

  • Mooyoung Han
    • 1
  • Seok Dockko
    • 2
  1. 1.Dept. of Civil Eng.Kyunghee Univ.Kyungki-DoKorea
  2. 2.Dept. of Environmental EngWoosuk Univ.ChunbukKorea

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