State estimation for a biological phosphorus removal process using an asymptotic observer

2001 ◽  
Vol 43 (11) ◽  
pp. 205-213 ◽  
Author(s):  
A. Larose ◽  
S. B. Jørgensen
Keyword(s):  
Steady State ◽  
State Estimation ◽  
Phosphorus Removal ◽  
Reaction Scheme ◽  
Biological Phosphorus Removal ◽  
Removal Process ◽  
Steady State Operation ◽  
Asymptotic Observer ◽  
Biological Phosphorus ◽  
High Condition

This study investigated the use of an asymptotic observer for state estimation in a continuous biological phosphorus removal process. The estimated states are the concentration of heterotrophic, autotrophic and phosphorus accumulating organisms, polyphosphate, glycogen and PHA. The reaction scheme describing the process was simplified from a combined ASM1-Delft model. Three examples were investigated: operation at steady state, operation at steady state with a random white-noise in the measurements and operation with a ramp disturbance. In each case, the estimation was quite accurate even if the convergence, driven by the dilution rate, was slow (from 15 to 60 days). The propagation of the measurement noise and a bias in the estimation of glycogen and PHA could be the result of the high condition number of one of the matrices used in the algorithm of the asymptotic observer for the aerated tanks.

A metabolic model for the biological phosphorus removal process

1995 ◽  
Vol 31 (2) ◽  
pp. 79-93 ◽  
Author(s):  
G. J. F. Smolders ◽  
M. C. M. van Loosdrecht ◽  
J. J. Heijnen
Keyword(s):  
Steady State ◽  
Phosphorus Removal ◽  
Metabolic Model ◽  
Biological Phosphorus Removal ◽  
Removal Process ◽  
Wide Range ◽  
Model Predictions ◽  
Derived Set ◽  
Metabolic Reactions ◽  
Biological Phosphorus

A structured metabolic model of the biological phosphorus removal process has been developed. In this approach the model is based on the bioenergetics and stoichiometry of the metabolism. All relevant metabolic reactions underlying the P-metabolism, considering also ATP and NADH2, are described. The derived set of stoichiometry based linear relations is used to reduce the number of reactions and conversions rates required to describe the process. The model predictions were experimentally verified by measurement of the external acetate, phosphate and ammonium concentrations as well as the internal fractions of PHB and glycogen. The model is applied to dynamic and steady-state situations over a wide range of sludge ages. The derived structured metabolic model is very well capable of describing the complex conversions of the biological phosphorus removal process.

A metabolic model of the biological phosphorus removal process: II. Validation during start-up conditions

1995 ◽  
Vol 48 (3) ◽  
pp. 234-245 ◽  
Author(s):  
G. J. F. Smolders ◽  
D. J. Bulstra ◽  
R. Jacobs ◽  
M. C. M. van Loosdrecht ◽  
J. J. Heijnen
Keyword(s):  
Phosphorus Removal ◽  
Metabolic Model ◽  
Biological Phosphorus Removal ◽  
Removal Process ◽  
Start Up ◽  
Biological Phosphorus

Behaviour of Intracellular Polyphosphate in the Biological Phosphate Removal Process

1985 ◽  
Vol 17 (11-12) ◽  
pp. 11-21 ◽  
Author(s):  
Takashi Mino ◽  
Tomonori Kawakami ◽  
Tomonori Matsuo
Keyword(s):  
Phosphorus Removal ◽  
Point Of View ◽  
Phosphate Removal ◽  
Phosphorus Compounds ◽  
Biological Phosphorus Removal ◽  
Removal Process ◽  
Phosphorus Source ◽  
Biological Phosphorus ◽  
Intracellular Phosphorus

In this study the functions of the intracellular polyphosphate in the biological phosphorus removal process were investigated from biological point of view. The STS method was used for the determination of polyphosphate and the fractionation of the intracellular phosphorus compounds. The lowmolecular polyphosphate and the highmolecular polyphosphate can be determined separately in this method. The radiotracer experiments were performed in which 32P-labeled orthophosphate was used as a tracer. The chemical analyses of phosphorus and the radioactivity measurement were made simultaniously in the course of the anaerobic oxic process. From the results of a radiotracer experiment the mass transfer of phosphorus among the phosphorus compounds was calculated. It was suggested that the lowmolecular polyphosphate served as the energy source under the anaerobic conditions and that the highmolecular polyphosphate served as the phosphorus source for the growth reactions. Some models for the phosphorus transfer in the high phosphorus accumulating microorganisms were proposed.

Saving phosphorus removal at the Henderson NV plant

2012 ◽  
Vol 65 (7) ◽  
pp. 1318-1322 ◽  
Author(s):  
J. Barnard ◽  
D. Houweling ◽  
H. Analla ◽  
M. Steichen
Keyword(s):  
Fatty Acids ◽  
Phosphorus Removal ◽  
Volatile Fatty Acids ◽  
Biological Phosphorus Removal ◽  
Case Histories ◽  
Mixed Liquor ◽  
Removal Process ◽  
Low Levels ◽  
Anaerobic Zone ◽  
Biological Phosphorus

While the mechanism of biological phosphorus removal (BPR) and the need for volatile fatty acids (VFA) have been well researched and documented to the point where it is now possible to design a plant with a very reliable phosphorus removal process using formal flow sheets, BPR is still observed in a number of plants that have no designated anaerobic zone, which was considered essential for phosphorus removal. Some examples are given in this paper. A theory is proposed and then applied to solve problems with a shortage of VFA in the influent of the Henderson NV plant. Mixed liquor was fermented in the anaerobic zone, which resulted in phosphorus removal to very low levels. This paper will discuss some of the background, and some case histories and applications, and present a simple postulation as to the mechanism and efforts at modelling the results.

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