Detailed model
Stationary surface without reaction:
Ul = 0, rA,ki= 0
The diffusion of a substance must be the same on both sides of the area because no
accumulation can take place in the interface with the given assumptions.
With these equations all processes can be described if we know the kinetic expressions for the processes; for variations in time and place, for random composition of the phase (types of bacteria) and for selected limiting conditions.
On the other hand it is not easy to solve these differential equations under the given
practical conditions.
However, today we have computer programs which are tailored for the solution of
these equations for conditions corresponding to the biofilm /23/. Such programs
will be increasingly used for analysis, operation and design.
In the next chapter an example is given which is based on a solution with this
program.
References
/1/ Harremoes, P. (1976): The Significance of Pore Diffusion to Filter Denitrification. Journal, WPCF, 48, No.2, 377-388.
/2/ Harremoes, P. and Riemer, M. (1977): Pilot-Scale Experiments on Down-Flow
Filter Denitrification. Progress in Water Technology, 8, No. 4/5,557-576
/3/ Harremoes, P. and Riemer, M. (1975). Report on Pilot Studies of Denitrification in Down-flow Filters, Department of Environmental Engineering,
Technical University of Denmark, Lyngby, Denmark
/4/ Harremoes, P. (1978}: Biofilm kinetics. Chapter 4 in: Mitchell, R. (ed.): Water
Pollution Microbiology, 2, s. 71-109. John Wiley & Sons, New York, N.Y.
/51 Perry, J. (1963): Chemical Engineers Handbook, McGraw-Hill.
/6/ Siegrist, H. and Gujer, W. (1985): Mass transfer Mechanisms in a Heterotrophic Biofilm. Water Research, 19, 1369-1378.
/7 I Triebel (ed.) (1975): Lehr- und Handbuch der Abwassertechnik, Bd II
(Textbook for Wastewater Engineering, Volume II). Verlag von Wilhelm Ernst
& Sohn, Berlin.
/8/ Abwassertechnishe Vereinigung (1985}: Lehr- und Handbuch der Abwassertechnik, Bd IV (Textbook for Wastewater Engineering, Volume IV), 900
pp, ISBN 3-433-00905-8, Ernst & Sohn.
/9/ Steels, I.H. (1974): Design Basis for the Rotating Disc Proces. Effluent and
Water Treatment Journal, 14, No.9, 431-445.
190
Stationary surface without reaction:
Ul = 0, rA,ki= 0
The diffusion of a substance must be the same on both sides of the area because no
accumulation can take place in the interface with the given assumptions.
With these equations all processes can be described if we know the kinetic expressions for the processes; for variations in time and place, for random composition of the phase (types of bacteria) and for selected limiting conditions.
On the other hand it is not easy to solve these differential equations under the given
practical conditions.
However, today we have computer programs which are tailored for the solution of
these equations for conditions corresponding to the biofilm /23/. Such programs
will be increasingly used for analysis, operation and design.
In the next chapter an example is given which is based on a solution with this
program.
References
/1/ Harremoes, P. (1976): The Significance of Pore Diffusion to Filter Denitrification. Journal, WPCF, 48, No.2, 377-388.
/2/ Harremoes, P. and Riemer, M. (1977): Pilot-Scale Experiments on Down-Flow
Filter Denitrification. Progress in Water Technology, 8, No. 4/5,557-576
/3/ Harremoes, P. and Riemer, M. (1975). Report on Pilot Studies of Denitrification in Down-flow Filters, Department of Environmental Engineering,
Technical University of Denmark, Lyngby, Denmark
/4/ Harremoes, P. (1978}: Biofilm kinetics. Chapter 4 in: Mitchell, R. (ed.): Water
Pollution Microbiology, 2, s. 71-109. John Wiley & Sons, New York, N.Y.
/51 Perry, J. (1963): Chemical Engineers Handbook, McGraw-Hill.
/6/ Siegrist, H. and Gujer, W. (1985): Mass transfer Mechanisms in a Heterotrophic Biofilm. Water Research, 19, 1369-1378.
/7 I Triebel (ed.) (1975): Lehr- und Handbuch der Abwassertechnik, Bd II
(Textbook for Wastewater Engineering, Volume II). Verlag von Wilhelm Ernst
& Sohn, Berlin.
/8/ Abwassertechnishe Vereinigung (1985}: Lehr- und Handbuch der Abwassertechnik, Bd IV (Textbook for Wastewater Engineering, Volume IV), 900
pp, ISBN 3-433-00905-8, Ernst & Sohn.
/9/ Steels, I.H. (1974): Design Basis for the Rotating Disc Proces. Effluent and
Water Treatment Journal, 14, No.9, 431-445.
190