Mathematical Model to Predict Solids Content of Water Treatment Residuals during Drying
Publication: Journal of Environmental Engineering
Volume 133, Issue 2
Abstract
Dewatering and drying of residuals are extremely energy intensive processes, which are necessary to reduce the quantity of wet residuals produced from the water and wastewater treatment operations. Meteorological conditions are a major factor in the drying of residuals, which can greatly affect the drying period. A mathematical model is developed for the process of drying of water treatment residuals. A steady-state heat-balance equation is applied for a control volume of residuals that takes into account the heat transfer by radiation, convection, and evaporation. The mathematical model was validated using drying experiments conducted in a wind tunnel as well as other experiments conducted in an open environment equipped with a weather monitoring station. Good agreement was obtained between model predictions and experimental observations. The model can be used to predict the drying time of a given application of water treatment residuals with the knowledge of meteorological conditions.
Get full access to this article
View all available purchase options and get full access to this article.
References
Berdahl, P., and Martin, M. (1984). “Emissivity of clear skies.” Sol. Energy, 32(5), 663–664.
Brutsaert, W. (1982). Evaporation into the atmosphere, Reidel, Dordrecht, The Netherlands.
Cengel, Y. A. (1997). Introduction to thermodynamics and heat transfer, McGraw-Hill, New York.
Clark, E. E. (1970). “Water treatment sludge drying and drainage on sand beds.” Ph.D. thesis, Univ. of Massachusetts, Amherst, Mass.
Gharaibeh, A., Sivakumar, M., and Dharmappa, H. B. (2001). “The effect of meteorological conditions on residuals drying.” Proc., 19th Federal convention, AWWA, Canberra, Australia.
Henderson, S. M. (1952). “A basic concept of equilibrium moisture.” Agric. Eng., 33, 29–32.
Hsu, S. A., and Meindl, E. A. (1994). “Determination of the power-law wind profile exponent under near-neutral stability conditions at sea.” J. Appl. Meteorol., 33, 757–765.
Incropera, F. P., and Dewitt, D. P. (1996). Fundamentals of heat and mass transfer, 4th Ed., Wiley, New York.
Lo, K.-M. (1971). “Digital computer simulation of water and wastewater sludge dewatering on sand beds.” Ph.D. thesis, Univ. of Massachusetts, Amherst, Mass.
McCabe, W. L., and Smith, J. C. (1976). Unit operations of chemical engineering, 3rd Ed., McGraw-Hill, New York.
Mujumdar, A. S. (1987). Handbook of industrial drying, Marcel Dekker, New York.
Munson, B. R., Young, D. F., and Okiishi, T. H. (1994). Fundamentals of fluid mechanics, 2nd Ed., Wiley, New York.
Murray, F. W. (1967). “On the computation of saturation vapour pressure.” J. Appl. Meteorol., 6, 203–204.
Nebiker, J. H. (1967). “The drying of wastewater sludge in the open air.” J. Water Pollut. Control Fed., 39(4), 608–628.
Palanz, B. (1984). “Analysis of solar-dehumidifying drying.” Int. J. Heat Mass Transfer, 27(5), 647–656.
Strumillo, C., and Kudra, T. (1986). Drying: Principles, applications, and design, Vol. 3, Gordon Breach Science, Montreux, Switzerland.
Tsang, K. R., and Vesilind, P. A. (1990). “Moisture distribution in sludges.” Water Sci. Technol., 22(12), 135–142.
Vaxelaire, J., Bongiovanni, J. M., and Puiggali, J. R. (1999). “Mechanical dewatering and thermal drying of residual sludge.” Environ. Technol., 20(1), 29–36.
Information & Authors
Information
Published In
Journal of Environmental Engineering
Volume 133 • Issue 2 • February 2007
Pages: 165 - 172
Copyright
© 2007 ASCE.
History
Received: Apr 18, 2006
Accepted: Jul 14, 2006
Published online: Feb 1, 2007
Published in print: Feb 2007
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.