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Experimental study to evaluate design procedure and proposed improvement measures for clarifier with inclined plates

  • Lee, Byonghi (Department of Environmental Energy Engineering, Kyonggi University)
  • 투고 : 2015.05.07
  • 심사 : 2015.08.31
  • 발행 : 2015.09.30

초록

The Standards for Water Works issued by the Korean government prescribed the insertion of inclined plates in a clarifier to enhance the settling of the suspended solids. In this study, in order to verify the role of the inclined plates, two identical laboratory-scale rectangular clarifiers were constructed and eight inclined plates were inserted into one of the clarifiers and inflow from same source was treated in both the clarifiers. Dye tests revealed that only the front three of the seven slots received the inflow at $0.57m^3/m^2{\cdot}h$, which was the highest SOR (surface overflow rate). Three different SORs, with 12 different SS (suspended solid) concentrations at each overflow rate, were fed to both clarifiers. However, the clarifier with the inclined plates failed to show an improved removal rate for the SS. In order to enable the Boycott effect within the slot, it is suggested that each slot created by the inclined plates receives equalized inflow. Moreover, collision of the inflow with the settled sludge at the bottom of the clarifier has to be avoided. These provisions, which can maximize the Boycott effect, should be added to the Standards for Water Works endorsed by Korean government.

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참고문헌

  1. Metcalf & Eddy (company). Wastewater Engineering - Treatment, Disposal and Reuse. 3rd ed. New York:McGraw-Hill;1991. p. 580-587.
  2. Hansen S, Culp G, Stukenberg J. Practical Application of Idealized Sedimentation Theory in Wastewater Treatment. Hansen, J. Water Pollut. Control Fed. 1969;41:1421-1444.
  3. Slechta A, Conley W. Recent Experiences in Plant-Scale Application of the Settling Tube Concept. J. Water Pollut. Control Fed. 1971;43:1724-1738.
  4. Hansen S, Culp G. Applying shallow depth sedimentation theory. J. Am. Water Works Assoc. 1967;59:1134-1148. https://doi.org/10.1002/j.1551-8833.1967.tb03501.x
  5. Boycott C. Sedimentation of blood corpuscles. Nature 1920;104:532-532. https://doi.org/10.1038/104532d0
  6. Nakamura N, Kuroda K. La cause de l'acceleration de la vitesse de sedimentation des suspensions dans les recipients inclines. Keijo J. Med. 1937;8:256-296.
  7. Yao K.M. Design of High-Rate Settlers. Journal of the Environmental Engineering Division. 1973;99:621-637.
  8. Galvin P, Nguyentranlam G. Influence of parallel inclined plates in a liquid fluidized bed system. Chem. Eng. Sci. 2002;57:1231-1234. https://doi.org/10.1016/S0009-2509(02)00005-2
  9. Ponder E. On sedimentation and rouleaux formation-1. Q. J. Exp. Physiol. 1925;15:235-252. https://doi.org/10.1113/expphysiol.1925.sp000356
  10. Xu Z, Michaelidesa E. A numerical simulation of the Boycott Effect. Chem. Eng. Commun. 2005;192: 532-549. https://doi.org/10.1080/00986440590477971
  11. Tripathi A, Acrivos A. A new criterion for the continuous operation of supersettlers in the bottom feeding mode. Int. J. Multiphase Flow 1996;22:353-361. https://doi.org/10.1016/0301-9322(95)00074-7
  12. Nir A, Acrivos A. Sedimentation and sediment flow on inclined surfaces. J. Fluid Mech. 1990;212:139-153. https://doi.org/10.1017/S0022112090001902
  13. Saady N. Effects of inclined plates and polyelectrolyte on the performance of settling tanks. J. Appl. Sci. Environ. Sanit. 2012;7:35-42.
  14. Hendricks D. Water Treatment Unit Processes: Physical and Chemical. New York: CRC Press; 2006. p. 184-193.
  15. Hane-Weijman H. Lamella separation old technology in a modern concept. J. Am. Water Works Assoc. 1990;82:803-817.
  16. Probstein F, Hicks R. Lamella settlers: a new operating mode for high performance. Industrial Water Engineering. 1978;15:6-8.
  17. Lamella Plate Settlers. Design and Operation: Two Case Histories [Internet]. Foellmi N, Bryant H: Lamella Plate Settlers; c2015 [cited 2015 Mar 3]. Available from: http://www.terrestorm.com/press_research_Foellmi_and_Bryant.pdf.
  18. Wenk S. The theory, design, and experience of Lamella Gravity Settlers in the phosphate industry. Fertilizer Research. 1990;25:139-143. https://doi.org/10.1007/BF01095094
  19. Shammas N, Kumar I, Chang SY, Hung YT. Sedimentation. In: Wang L, Hung YT, Shammas N, eds. hysicochemical Treatment Process. Totowa: Humana Press Inc; 2004. p. 406-412.
  20. Miller R. New separation may spur interest in sedimentation. Water & wastes engineering 1974;11:40-42.
  21. Kolisch G, Schirmer G. Lamella separators in the upgrading of a large urban sewage treatment plant. Water Sci. Technol. 2004;50:205-212.
  22. Stevenson D. Water Treatment Unit Processes, In: Stevenson D, eds. London: Imperial College Press; 1997. p. 151-162.
  23. MWH. Water Treatment: Principles and Design. 2nd ed. Hoboken: John wiley & Sons Inc; 2005. p. 820-831.
  24. KWWA. Standards for Water Works issued by Ministry of Environment (in Korean). Seoul: Korean Water and Wastewater Work Association; 2010. p. 346-352.
  25. Neo-Envitech, URC Process [Internet]. Neo-Envitech; c2015 [cited 2015 Mar 5]. Available from: http://www.neoenvitech.com.
  26. Veolia. Actflo [Internet]. Veolia: c2015 [cited 2015 Mar 5]. Available from: http://technomaps.veoliawatertechnologies.com/actiflo/en.
  27. Samstag W, Wicklein A, Lee B. Computational Analysis of Activated Sludge Lamellar Sedimentation. In: IWA World Water Congress & Exhibition 2012 Poster session; 2012 Sep 16-21; Busan, South Korea.