Modeling of enhanced biological phosphorus removal in a sequencing batch biofilm reactor

1998 ◽  
Vol 37 (4-5) ◽  
pp. 583-587 ◽  
Author(s):  
Eberhard Morgenroth ◽  
Peter A. Wilderer
Keyword(s):  
Mathematical Model ◽  
Phosphorus Removal ◽  
Heterotrophic Bacteria ◽  
Biofilm Reactor ◽  
Phosphorus Concentration ◽  
Enhanced Biological Phosphorus Removal ◽  
Biological Phosphorus Removal ◽  
Biofilm Thickness ◽  
The Mathematical Model ◽  
Biological Phosphorus

A biofilm system operated for enhanced biological phosphorus removal is evaluated using a mathematical model. The influence of the influent COD concentration and the biofilm thickness are investigated. In an activated sludge system increasing the influent COD will result in a decrease of the effluent phosphorus concentration. However, in a biofilm system above a certain influent COD concentration not all COD supplied in the influent can be taken up during the anaerobic period. Other heterotrophic bacteria will then dominate the biofilm resulting in an increase of the effluent phosphorus concentration. A larger biofilm thickness will result in an increase of the total mass of polyphosphate-accumulating organisms in the system. However, it is shown that a larger biofilm thickness results in higher effluent phosphorus concentrations. The mathematical model presented is based on the IAWQ Model No. 2 modified for the biofilm system. Mass transport in the biofilm is modeled one-dimensionally. Removal of biomass through backwashing and, thus, removal of phosphorus, is included in the mathematical model. Simulations were used to explain experimental observations.

Design of nutrient removal activated sludge systems

2003 ◽  
Vol 47 (11) ◽  
pp. 115-122 ◽  
Author(s):  
J. Manga ◽  
J. Ferrer ◽  
A. Seco ◽  
F. Garcia-Usach
Keyword(s):  
Mathematical Model ◽  
Activated Sludge ◽  
Nutrient Removal ◽  
Phosphorus Removal ◽  
Pilot Plant ◽  
Enhanced Biological Phosphorus Removal ◽  
Biological Phosphorus Removal ◽  
User Friendly ◽  
Biological Phosphorus ◽  
Activated Sludge Systems

A mechanistic mathematical model for nutrient and organic matter removal was used to describe the behavior of a nitrification denitrification enhanced biological phosphorus removal (NDEBPR) system. This model was implemented in a user-friendly software DESASS (design and simulation of activated sludge systems). A 484-L pilot plant was operated to verify the model results. The pilot plant was operated for three years over three different sludge ages. The validity of the model was confirmed with data from the pilot plant. Also, the utility of DESASS as a valuable tool for designing NDEBPR systems was confirmed.

Experience from 10 years of full-scale operation with enhanced biological phosphorus removal at Öresundsverket

2005 ◽  
Vol 52 (12) ◽  
pp. 151-159 ◽  
Author(s):  
E. Tykesson ◽  
L.-E. Jönsson ◽  
J. la Cour Jansen
Keyword(s):  
Phosphorus Removal ◽  
Volatile Fatty Acids ◽  
Stable Process ◽  
Full Scale ◽  
Phosphorus Concentration ◽  
Enhanced Biological Phosphorus Removal ◽  
Biological Phosphorus Removal ◽  
Sludge Hydrolysis ◽  
Low Levels ◽  
Biological Phosphorus

Ten years of full-scale experience with enhanced biological phosphorus removal (EBPR) has been evaluated. During the start-up period lack of carbon source was the main operational problem and a higher level of volatile fatty acids was secured by introducing a primary sludge hydrolysis. Acidic thermal sludge hydrolysis was used as the sludge treatment method at the plant during about three years. One effluent stream, rich in carbon and precipitant, was brought back to the process leading to an improvement of the phosphorus removal both by an improved biological process and chemical precipitation. A quite stable process of EBPR was developed with low levels of effluent phosphorus concentration. Stringent effluent discharge limits during short evaluation periods necessitated a continued work for improvement of the short-term stability. During periods with lack of carbon, such as industrial holiday or rainy periods, both simultaneous precipitation and reduced aeration have been successfully tested as strategies for securing low levels of effluent phosphorus.

Enhanced biological phosphorus removal in a semifull-scale SBBR

2001 ◽  
Vol 43 (3) ◽  
pp. 167-174 ◽  
Author(s):  
P. Arnz ◽  
E. Arnold ◽  
P. A. Wilderer
Keyword(s):  
Phosphorus Removal ◽  
Operation Mode ◽  
Biofilm Reactor ◽  
Enhanced Biological Phosphorus Removal ◽  
Biological Phosphorus Removal ◽  
Aeration Time ◽  
Start Up ◽  
Main Carbon Source ◽  
In The Beginning ◽  
Biological Phosphorus

A 17 m3 Sequencing Batch Biofilm Reactor (SBBR) was operated for enhanced biological phosphorus removal and nitrification for a period of 384 days. Enhanced biological phosphorus removal (EBPR) activity was instantly induced after start-up of EBPR operation mode and low phosphate effluent values were reached from the first batch onward. Process stability with regard to nitrification and EBPR were very good although high nitrate loads from backwashing disturbed the P removal performance. Due to anoxic conditions in the beginning of the cycle, readily degradable COD was depleted by denitrification. Consequently, particulate matter was the main carbon source for phosphorus accumulating organisms. Anaerobic hydrolysis or fermentation was found to be the rate limiting process in the SBBR cycle. Simultaneous denitrification occurred in the first 30 minutes of aeration and - to a lesser extent - during the remaining aeration time, enhancing nitrogen removal and indirectly also phosphorus removal.

Heterotrophic Kinetic Parameter Estimation for Enhanced Biological Phosphorus Removal Processes Operated in Conventional and Membrane-Assisted Modes

2006 ◽  
Vol 41 (1) ◽  
pp. 72-83 ◽  
Author(s):  
Zhe Zhang ◽  
Eric R. Hall
Keyword(s):  
Parameter Estimation ◽  
Phosphorus Removal ◽  
Growth Yield ◽  
Pilot Scale ◽  
Enhanced Biological Phosphorus Removal ◽  
Biological Phosphorus Removal ◽  
Nitrogen And Phosphorus ◽  
Parameter Values ◽  
The Impact ◽  
Biological Phosphorus

Abstract Parameter estimation and wastewater characterization are crucial for modelling of the membrane enhanced biological phosphorus removal (MEBPR) process. Prior to determining the values of a subset of kinetic and stoichiometric parameters used in ASM No. 2 (ASM2), the carbon, nitrogen and phosphorus fractions of influent wastewater at the University of British Columbia (UBC) pilot plant were characterized. It was found that the UBC wastewater contained fractions of volatile acids (SA), readily fermentable biodegradable COD (SF) and slowly biodegradable COD (XS) that fell within the ASM2 default value ranges. The contents of soluble inert COD (SI) and particulate inert COD (XI) were somewhat higher than ASM2 default values. Mixed liquor samples from pilot-scale MEBPR and conventional enhanced biological phosphorus removal (CEBPR) processes operated under parallel conditions, were then analyzed experimentally to assess the impact of operation in a membrane-assisted mode on the growth yield (YH), decay coefficient (bH) and maximum specific growth rate of heterotrophic biomass (µH). The resulting values for YH, bH and µH were slightly lower for the MEBPR train than for the CEBPR train, but the differences were not statistically significant. It is suggested that MEBPR simulation using ASM2 could be accomplished satisfactorily using parameter values determined for a conventional biological phosphorus removal process, if MEBPR parameter values are not available.

Full Scale Investigations on Enhanced Biological Phosphorus Removal – P-Release in the Anaerobic Reactor

1994 ◽  
Vol 29 (7) ◽  
pp. 153-156 ◽  
Author(s):  
D. Wedi ◽  
P. A. Wilderer
Keyword(s):  
Phosphorus Removal ◽  
Full Scale ◽  
Process Conditions ◽  
Enhanced Biological Phosphorus Removal ◽  
Biological Phosphorus Removal ◽  
Anaerobic Reactor ◽  
P Release ◽  
Acinetobacter Sp ◽  
Biological Phosphorus ◽  
P Removal

Most of the fundamental processes responsible for enhanced biological phosphorus removal (EBPR) were obtained through laboratory tests under defined conditions with pure or enriched cultures. Acinetobacter sp. was identified as the most important group of bacteria responsible for bio-P removal. Full scale data showed, however, that laboratory results do not match full scale results well enough. There is a lack of data on the effects of sub-optimal process conditions such as inadequate availability of volatile fatty acids (VFA), high nitrate recycle, storm water inflow or low temperatures. In this paper the results of full scale experiments on P-release are presented and compared with theoretical values. Measurements at a full scale Phoredox-system showed a surprisingly low P-release in the anaerobic reactor. Only 4 to 10% of the phosphorus in the activated sludge was released in the bulk liquid. With laboratory batch-tests, a maximum of 20% of the P in the sludge could be released. It is assumed that under the prevailing process conditions either the fraction of Acinetobacter sp. was very small, or bacteria other than Acinetobacter sp. were responsible for the P-removal, or most of the phosphorus was bound chemically but mediated by biological processes.

A flux-based stoichiometric model of enhanced biological phosphorus removal metabolism

1998 ◽  
Vol 37 (4-5) ◽  
pp. 609-613
Author(s):  
J. Pramanik ◽  
P. L. Trelstad ◽  
J. D. Keasling
Keyword(s):  
Phosphorus Removal ◽  
Reaction Network ◽  
Bacterial Biomass ◽  
Enhanced Biological Phosphorus Removal ◽  
Biological Phosphorus Removal ◽  
Stoichiometric Model ◽  
Aerobic Reactor ◽  
Complete Set ◽  
Biological Phosphorus

Enhanced biological phosphorus removal (EBPR) in wastewater treatment involves metabolic cycling through the biopolymers polyphosphate (polyP), polyhydroxybutyrate (PHB), and glycogen. This cycling is induced through treatment systems that alternate between carbon-rich anaerobic and carbon-poor aerobic reactor basins. While the appearance and disappearance of these biopolymers has been documented, the intracellular pressures that regulate their synthesis and degradation are not well understood. Current models of the EBPR process have examined a limited number of metabolic pathways that are frequently lumped into an even smaller number of “reactions.” This work, on the other hand, uses a stoichiometric model that contains a complete set of the pathways involved in bacterial biomass synthesis and energy production to examine EBPR metabolism. Using the stoichiometric model we were able to analyze the role of EBPR metabolism within the larger context of total cellular metabolism, as well as predict the flux distribution of carbon and energy fluxes throughout the total reaction network. The model was able to predict the consumption of PHB, the degradation of polyP, the uptake of acetate and the release of Pi. It demonstrated the relationship between acetate uptake and Pi release, and the effect of pH on this relationship. The model also allowed analysis of growth metabolism with respect to EBPR.

Optimising the A/O cycle for phosphorus removal in a submerged biofilter under continuous feed

2000 ◽  
Vol 41 (4-5) ◽  
pp. 503-508 ◽  
Author(s):  
R.F. Gonçalves ◽  
F. Rogalla
Keyword(s):  
Phosphorus Removal ◽  
Organic Substrate ◽  
P Element ◽  
Enhanced Biological Phosphorus Removal ◽  
Biological Phosphorus Removal ◽  
P Release ◽  
Continuous Feed ◽  
Biological Phosphorus ◽  
Total P ◽  
Selection Of

This work describes laboratory scale research about Enhanced Biological Phosphorus Removal (EBPR) in a submerged biofilter under Anaerobic/Oxic (A/O) alternation and continuous feed. Its main purpose is to detail the behaviour of the reactor throughout the anaerobic and the aerobic phases of the A/O cycle, to study the importance of the anaerobic phase in the selection of the EBPR bacteria in the biofilm and to evaluate the consumption and the importance of the organic substrate during the anaerobic phase. The mass balance over the Phosphorus (P) element indicates that long anaerobic phases (6 h) are more efficient than short ones (3 h) as a selector of EBPR bacteria in biofilms. In both comparisons, thespecific mass of P released in a 6 h period represents almost 50% more than the amount of P release in the shorter period (3 h). However, the presence of rapidly biodegradable COD in the influent of the anaerobic phase is a more effective selector, more important than the duration of the anaerobic phase: by doubling the amount of acetic acid in the influent, a similar 50% increase of P-release can be achieved at short anaerobic periods of 3 h. The effect of the strategy adopted in this study, focusing on selecting EBPR bacteria in biofilm, is shown by the P levels of 4% (total P/SST) in the sludge removed from the BF by backwashing in all periods.

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