Abstract
The activated sludge process is one of the most frequently used processes for biological wastewater treatment. Conventional gravity sedimentation (CGS), which is widely used as a secondary clarifier in activated sludge processes, has a routine problem due to floating tendency, called bulking, caused by filamentous microorganisms. Dissolved air flotation (DAF) has been applied as potential alternative to CGS as a secondary clarifier. A series of experiments were performed to measure physico-chemical characteristics and removal efficiency of activated sludge flocs. The removal efficiency of flocs corresponding in lag and exponential growth phases was lower, while that of flocs both in stationary and endogenous phases considerably increased. The rise velocity of floc/bubble agglomerates was calculated by using a population balance (PB) model explaining the distribution of floc/bubble agglomerates. The experimental results of flotation efficiency showed a similar tendency with the results predicted by PB model for the rise velocity and distribution of floc/bubble agglomerates. It was found from our study that the DAF process was very effective as a secondary clarifier in the activated sludge process.
Similar content being viewed by others
References
American Public Health Association, American Water Works Association and Water Pollution Control Federation (APHA-AWWA-WPCF), Standard methods for the examination of water and wastewater, 20th ed., Washington, DC (1998).
Bourgeois, J. C., Walsh, M. E. and Gagnon, G.A., “Treatment of drinking water residuals: comparing sedimentation and dissolved air flotation performance with optimal cation ratios,”Wat. Res.,38, 1173 (2004).
Clift, R., Grace, J. R. and Weber, M. E.,Bubbles, drops, and particles, Academic Press, New York (1978).
Edzwald, J. K., “Principles and applications of dissolved air flotation,”Wat. Sci. Tech.,31(3-4), 1 (1995).
Fukushi, K., Tambo, N. and Matsui, Y., “A kinetic model for dissolved air flotation in water and wastewater treatment,”Wat. Sci. Tech. 31(3-4), 37 (1995).
Kalinske, A. A. and Evans, R. R.,Comparison of flotation and sedimentation in treatment of industrial wastes, Proceeding of Industrial Waste Conference 8th, pp. 64–71 (1953).
Kwak, D. H., Jung, H. J., Kim, S. J. and Lee, J. W., “Separation characteristics of inorganic particles from rainfalls in dissolved air flotation: A Korean perspective,”J. Sep. Tech.,40, 3001 (2005).
Lee, J. E., Choi, W S. and Lee, J. K., “A study of the bubble properties in the column flotation system,”Korean J. Chem. Eng.,20, 942 (2003).
Lee, J. M.,Biochemical engineering, Prentice-Hall, New Jersey, 2nd ed. (1992).
Lee, J. W., Jung, H. J., Kwak, D. H. and Chung, P. J., “Adsorption of dichloromethane from water onto a hydrophobic polymer resin XAD-1600,”Wat. Res.,39, 617 (2005).
Lee, J. W., Yang, T. H., Jung, H. J., Kim, S. J. and Kwak, D. H., “Flotation efficiency of powdered activated carbon in dissolved air flotation process,”Wat. Res. (under review, 2005).
Lee, M. G. and Hano, T., “Effects of hourly load variation on treatment characteristics in anaerobic-aerobic activated sludge process,”Korean J. Chem. Eng.,18, 178 (2001).
Leppinen, D. M., Dalziel, S. B. and Linden, P. F., “Modeling the global efficiency of dissolved air flotation,”Wat. Sci. Tech.,43(8), 159 (2001).
Leppinen, D. M. and Dalziel, S. B., “Bubble size distribution in dissolved air flotation tanks,”J. Wat. Suppl: Res. & Tech.-AQUA,53(8), 531 (2004).
Liers, S., Baeyens, J. and Mochtar, I., “Modeling dissolved air flotation,”Water Environ. Res.,68(6), 1061 (1996).
Matsui, Y., Fukushi, K. and Tambo, N., “Modeling, simulation and operation parameters of dissolved air flotation,”J. Wat. Suppl: Res. & Tech.-AQUA,47, 9 (1998).
Martins, A. M. P., Pagilla, K., Heijnen, J. J. and Loosdrecht, M. C. M., “Filamentous bulking sludge a critical review,”Wat. Res.,38, 793 (2004).
Reid, R. C., Prausnitz, J. M. and Poling, B. E.,The properties of gases and liquids, McGraw-Hill, 4th ed. (1987).
Rodrigues, R. T. and Rubio, J., “New basis for measuring the size distribution of bubbles,”Min. Eng.,16, 757 (2003).
Tambo, N. and Fukushi, K., “A kinetic study of dissolved air flotation,”J. JWWA,606, 22 (1985).
Tambo, N., Fukushi, K. and Matsui, Y., “An analysis of air bubble attachment process of dissolved air flotation,”J. JWWA,610, 2 (1985).
Vlyssides, A.G., Mai, S. T. and Barampouti, E. M., “Bubble size distribution formed by depressurizing air-saturated water,”Ind. Eng. Chem. Res.,43, 2775 (2004).
Zabel, T., “The advantages of dissolved-air flotation for water treatment,”J.AWWA,77(5), 42 (1985).
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Jung, HJ., Lee, JW., Choi, DY. et al. Flotation efficiency of activated sludge flocs using population balance model in dissolved air flotation. Korean J. Chem. Eng. 23, 271–278 (2006). https://doi.org/10.1007/BF02705726
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF02705726