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Estimating the hindered-settling flux function from a batch test in a cone

Bürger, Raimund; Careaga, Julio LU ; Diehl, Stefan LU ; Merckel, Ryan and Zambrano, Jesús (2018) In Chemical Engineering Science 192. p.244-253
Abstract

The hindered-settling velocity function for the modelling, simulation and control of secondary settling tanks can be determined from batch tests. The conventional method is to measure the velocity of the descending sludge-supernatant interface (sludge blanket) as the change in height over time in a vessel with constant cross-sectional area. Each such experiment provides one point on the flux curve since, under idealizing assumptions (monodisperse suspension, no wall-effects), the concentration of sludge remains constant just below the sludge blanket until some wave from the bottom reaches it. A newly developed method of estimation, based on the theory of nonlinear hyperbolic partial differential equations, is applied to both synthetic... (More)

The hindered-settling velocity function for the modelling, simulation and control of secondary settling tanks can be determined from batch tests. The conventional method is to measure the velocity of the descending sludge-supernatant interface (sludge blanket) as the change in height over time in a vessel with constant cross-sectional area. Each such experiment provides one point on the flux curve since, under idealizing assumptions (monodisperse suspension, no wall-effects), the concentration of sludge remains constant just below the sludge blanket until some wave from the bottom reaches it. A newly developed method of estimation, based on the theory of nonlinear hyperbolic partial differential equations, is applied to both synthetic and experimental data. The method demonstrates that a substantial portion of the flux function may be estimated from a single batch test in a conical vessel. The new method takes into consideration that during an ideal settling experiment in a cone, the concentration just below the sludge blanket increases with time since the mass of suspended solids occupy a reduced volume over time.

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Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Identification, Inverse problem, Partial differential equation, Sedimentation
in
Chemical Engineering Science
volume
192
pages
10 pages
publisher
Elsevier
external identifiers
  • scopus:85050301217
ISSN
0009-2509
DOI
10.1016/j.ces.2018.07.029
language
English
LU publication?
yes
id
02a90e3c-6a42-47f5-ba1c-21f0bef578aa
date added to LUP
2018-08-14 10:32:37
date last changed
2019-03-19 03:58:06
@article{02a90e3c-6a42-47f5-ba1c-21f0bef578aa,
  abstract     = {<p>The hindered-settling velocity function for the modelling, simulation and control of secondary settling tanks can be determined from batch tests. The conventional method is to measure the velocity of the descending sludge-supernatant interface (sludge blanket) as the change in height over time in a vessel with constant cross-sectional area. Each such experiment provides one point on the flux curve since, under idealizing assumptions (monodisperse suspension, no wall-effects), the concentration of sludge remains constant just below the sludge blanket until some wave from the bottom reaches it. A newly developed method of estimation, based on the theory of nonlinear hyperbolic partial differential equations, is applied to both synthetic and experimental data. The method demonstrates that a substantial portion of the flux function may be estimated from a single batch test in a conical vessel. The new method takes into consideration that during an ideal settling experiment in a cone, the concentration just below the sludge blanket increases with time since the mass of suspended solids occupy a reduced volume over time.</p>},
  author       = {Bürger, Raimund and Careaga, Julio and Diehl, Stefan and Merckel, Ryan and Zambrano, Jesús},
  issn         = {0009-2509},
  keyword      = {Identification,Inverse problem,Partial differential equation,Sedimentation},
  language     = {eng},
  month        = {12},
  pages        = {244--253},
  publisher    = {Elsevier},
  series       = {Chemical Engineering Science},
  title        = {Estimating the hindered-settling flux function from a batch test in a cone},
  url          = {http://dx.doi.org/10.1016/j.ces.2018.07.029},
  volume       = {192},
  year         = {2018},
}