Journal of Korean Society of Water and Wastewater (상하수도학회지)

The Korean Society of Water and Wastewater (대한상하수도학회)
권호 표지

Theoretical Approach to Calculating rms-Velocity Gradient in Flocculators

응집지 속도경사(G) 계산에 대한 이론적인 고찰

  • 김자겸 (한국수자원공사 수도관리1처)
  • Received : 2004.02.16
  • Accepted : 2004.04.20
  • Published : 2004.06.15
Download PDF
⟨ Previous Next ⟩

Abstract

Selecting appropriate G values in flocculator operation is important to produce high quality filter effluent in water treatment plants. However, misunderstanding and misleading of G calculation for the case of having power sources more than one or many paddles with one power source in a flocculation basin sometimes have led to low performance in flocculation. Theoretical analysis confirmed that the total G value in one flocculation unit having power sources more than one or with many paddles is the root-square of the sum of square of individual G value. This analysis also can give a simple calculation method of G value for designers and operators in fields.

Keywords

References

  1. Camp, T.R. and Stein, P.C. (1943) Velocity Gradients and Internal Work in Fluid Motion, J. Boston Soc. Civil Engineers, 30, pp. 219-237
  2. Camp, T.R. (1955) Flocculation and Flocculation Basins, Trans., ASCE, 120, pp. 1-16
  3. Clark, M.M. (1985) Critique of Camp and Stein's rms velocity gradient, Jour. of Environ. Engineering, ASCE, 111(6), pp. 741-764
  4. Han, M., and Lawler, D.F. (1992)The (relative) Insignificance of G in Flocculation, JAWWA, 84(10), pp. 79-91
  5. Johnson, C.P., Li, X.Y., and Logan, B.E., (1996) Settling Velocities of Fractal Aggregates, Environ, Sci. Technol., 30, pp.1911-1918
  6. Kawamura, S. (2000) Integrated Design and Operation of Water Treatment Facilities. 2nd Ed. p. 131, John Wiley & Sons, Inc., New York
  7. Li, X.Y., and Yuan, Y. (2002) Settling Velocities and Permeabilities of Microbial Aggregates, Water Research, 36, pp.3110-3120
  8. O'Melia, C.R. (1978) Coagulation in Water Treatment in The Scientific Basis of Flocculation, K.J. Ives ed., p. 73, KLEWAR Academic Publishers, The Netherlands
  9. Smoluchowski, M. (1917) Versuch einer mathematischen Theorie der Koagulationskinetic kolloider Losunger, Zeitschrift Physicalische Chemie, 92, pp. 129