Development of Dissolved Air Flotation Technology from 1st Generation to the Newest or 3rd One (Very Thick Microbubble Bed) with High Flowrates DAF in Turbulent Flow Conditions

차세대 고효율 용존공기 부상공정(High Rate DAF)의 개발

  • Kiuru, H.J. (Dept. of Water and Wastewater Engineering, Helsinki University of Technology)
  • Received : 2003.11.05
  • Accepted : 2004.02.26
  • Published : 2004.04.15

Abstract

Dissolved air flotation (DAF), in which suspended solids are removed from water by means of micro-size air bubbles raising slowly up in water and lifting solids from water (smaller than those) attached onto the micro-bubbles as well as those (larger than solids) being attached on these, have been used in water and wastewater since 1920s. The dissolved air flotation technology was originally based on the laminar flow conditions prevailing in water to be treated, but the latest development in that technology has led now to a situation, in which the flow conditions may also be turbulent ones in the modem dissolved air flotation units. Despite of that, the flotation phenomenon used in this unit operation for removal suspended solids from water or wastewater is still the same.

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References

  1. Eades, A.,Jordan, D., Scheidler, S., (1997) Counter-current Dissolved Air Flotation COCO-DAFF, Dissolved Air Flotation, ClWEM, London, pp. 323-340
  2. Edzwald, J., (1993) Coagulation in drinking water treatment: particles, organics and coagulants, Water Saence and Tech., 27,pp.21-35
  3. Edzwald, J., Olson, S.C., Tamulonis, C.W., (1994) DAF: Field Investigations, AWWA Reseach Foundation
  4. Edzwald,J., (1995) Principles and applications of DAF, Water S챠두ce and Tecb., 31, pp. 1-23
  5. Edzwald, J., (1997) Contact zone modelling and the role of pretreatment in DAF performance, Dissolved Air flotation, ClWEM, London, pp.9-23
  6. Fukushi, K, Tambo, N., Matui, Y., (1994) A kinetic modelfor dissolved air flotation in water and wastewater treatment, Proceedings of IAQW-IWSA-AWWA Joint Specialized Conference, Orlando, pp. 13-22
  7. Haarhoff J., (1997) Towards the maximal utilization of air in Dissolved Air Flotation, CIWEM, pp. 25-34
  8. Han, M. Y, (2002). Modeling of DAF: the effect of particle and bubble characteristics, AQUA, 51(1), pp.27-34
  9. Jokela P., (1997) Dissolved air flotation treatment of surface waters for high quality process water in the foreset industry, CIWEM, pp.417-428
  10. Krofta, M., Wang,L.X, (1982) Potable water treatment by DAF and filtration,J. of AWWA, pp. 305-310
  11. Sander E. de Rijk et al.,(1994), Bubble size in flotation thickening, Water Research, 28(2), 465-473
  12. Schulze, H. J., (1984) Physico-chemical elementary processes in flotation, Elsevier
  13. Vlaski A. et al., (1997) Algal laden watertreatment by dissolved air flotation, CJWEM, pp.215-238
  14. Zabel, T.,(1985) Advantages of DAF for water treatment, J. of AWWA, 5, pp.42-46