Deterministic-Based Model of Slow Sand Filtration. I: Model Development

Slow sand filtration (SSF) is widely used throughout the world for the treatment of drinking water. However, relatively little attention has been given to the development of a comprehensive process model. Previous studies have considered separate aspects of the SSF process, such as developing an improved representation of the schmutzdecke layer, and a more detailed description of the microbial dynamics. The objective of this work was to develop a deterministic simulation model of the SSF process incorporating fundamental physicochemical and biological dynamics within a classical filtration framework. The model was based on a temporal and spatial finite difference method and was calibrated and verified using operational data from pilot-scale SSF units. Results from the calibration showed that the model satisfactorily predicts headloss development in SSF units. There was no significant difference between many of the most sensitive model parameter values for two successive runs of the same filter. However, a few individual model parameters (e.g., in the fundamental headloss equations) were found to vary with filtration run and it is speculated that this is due to seasonal factors.

[1]  D. D. Toro,et al.  Optics of turbid estuarine waters: Approximations and applications , 1978 .

[2]  Steven C. Chapra,et al.  Numerical Methods for Engineers , 1986 .

[3]  David W. Hendricks,et al.  Slow Sand Filtration , 1985 .

[4]  T. Mbwette.  The performance of fabric protected slow sand filters , 1989 .

[5]  John Happel,et al.  Viscous flow relative to arrays of cylinders , 1959 .

[6]  L. Campos,et al.  Biomass development in slow sand filters. , 2002, Water research.

[7]  J. Herzig,et al.  Flow of Suspensions through Porous Media—Application to Deep Filtration , 1970 .

[8]  Chandra Shekhar P. Ojha,et al.  Computer-aided simulation of slow sand filter performance , 1994 .

[9]  N.J.D Graham,et al.  Improving the efficiency of slow sand filtration with non-women synthetic fabrics , 1987 .

[10]  S. Chapra.  Surface Water-Quality Modeling , 1996 .

[11]  K J Ives,et al.  ABSTRACT. RATIONAL DESIGN OF FILTERS. , 1960 .

[12]  Luiza C. Campos,et al.  Deterministic-Based Model of Slow Sand Filtration. II: Model Application , 2006 .

[13]  C. Curds.  Computer simulations of some complex microbial food chains , 1974 .

[14]  Tomihisa Iwasaki,et al.  Some Notes on Sand Filtration , 1937 .

[15]  G. T. Orlob.  Mathematical Modeling of Water Quality: Streams, Lakes and Reservoirs , 1983 .

[16]  D. Strayer,et al.  Photosynthetically produced dissolved organic carbon: An important carbon source for planktonic bacteria1 , 1982 .

[17]  S. Jørgensen.  Handbook of Ecological Parameters and Ecotoxicology , 1991 .

[18]  Mansour G. Ibrahim.  Ecological studies on the ciliate and bacterial populations of slow sand filters , 1989 .

[19]  T. J. Hart.  Oceanography of Long Island Sound , 1960, Nature.