On the modelling of the dynamic propagation of biological components in the secondary clarifier
(1996) In Water Science and Technology 34(5). p.8592 Abstract
 When coupling a model of the biological reactor to a model of the settler, difficulties appear because of the different representations used for the particulate material. A combined model of the entire activated sludge process needs to include an algorithm for the dynamic propagation of the biological components of the particulate material through the secondary clarifier. In particular, this is of importance for an accurate description of the sludge that is recycled to the biological reactor. Two onedimensional algorithms have been evaluated by means of numerical simulations. The first algorithm investigated is the one by Otterpohl and Freund in 1992 and some inherent problems of this method are discussed. For example, it will produce... (More)
 When coupling a model of the biological reactor to a model of the settler, difficulties appear because of the different representations used for the particulate material. A combined model of the entire activated sludge process needs to include an algorithm for the dynamic propagation of the biological components of the particulate material through the secondary clarifier. In particular, this is of importance for an accurate description of the sludge that is recycled to the biological reactor. Two onedimensional algorithms have been evaluated by means of numerical simulations. The first algorithm investigated is the one by Otterpohl and Freund in 1992 and some inherent problems of this method are discussed. For example, it will produce oscillating solutions as the number of layers in the settler model increases. Therefore, an alternative algorithm is proposed. It is based on a percentage vector that describes the different particulate biological components as fractions of the total suspended solids concentration. The vector is updated for every layer in the settler model by a robust numerical method. The algorithm is derived analytically, is computationally efficient and does not exhibit any oscillatory behaviour. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/record/792891
 author
 Jeppsson, Ulf ^{LU} and Diehl, Stefan ^{LU}
 organization
 publishing date
 1996
 type
 Contribution to journal
 publication status
 published
 subject
 keywords
 thickening, suspended solids, solids flux, simulation, secondary clarifier, onedimensional model, mathematical modelling, clarification, Activated sludge
 in
 Water Science and Technology
 volume
 34
 issue
 5
 pages
 85  92
 publisher
 IWA Publishing
 external identifiers

 scopus:0029957161
 ISSN
 02731223
 DOI
 10.1016/02731223(96)006324
 language
 English
 LU publication?
 yes
 id
 7d3491233a6f4578b4e72c57a121405c (old id 792891)
 alternative location
 http://www.iwaponline.com/wst/03405/0085/034050085.pdf
 date added to LUP
 20080204 16:58:05
 date last changed
 20180107 09:40:21
@article{7d3491233a6f4578b4e72c57a121405c, abstract = {When coupling a model of the biological reactor to a model of the settler, difficulties appear because of the different representations used for the particulate material. A combined model of the entire activated sludge process needs to include an algorithm for the dynamic propagation of the biological components of the particulate material through the secondary clarifier. In particular, this is of importance for an accurate description of the sludge that is recycled to the biological reactor. Two onedimensional algorithms have been evaluated by means of numerical simulations. The first algorithm investigated is the one by Otterpohl and Freund in 1992 and some inherent problems of this method are discussed. For example, it will produce oscillating solutions as the number of layers in the settler model increases. Therefore, an alternative algorithm is proposed. It is based on a percentage vector that describes the different particulate biological components as fractions of the total suspended solids concentration. The vector is updated for every layer in the settler model by a robust numerical method. The algorithm is derived analytically, is computationally efficient and does not exhibit any oscillatory behaviour.}, author = {Jeppsson, Ulf and Diehl, Stefan}, issn = {02731223}, keyword = {thickening,suspended solids,solids flux,simulation,secondary clarifier,onedimensional model,mathematical modelling,clarification,Activated sludge}, language = {eng}, number = {5}, pages = {8592}, publisher = {IWA Publishing}, series = {Water Science and Technology}, title = {On the modelling of the dynamic propagation of biological components in the secondary clarifier}, url = {http://dx.doi.org/10.1016/02731223(96)006324}, volume = {34}, year = {1996}, }