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.

An enhanced biological phosphorus removal (EBPR) control strategy for sequencing batch reactors (SBRs)

2001 ◽  
Vol 43 (3) ◽  
pp. 183-189 ◽  
Author(s):  
C. Y. Dassanayake ◽  
R. L. Irvine
Keyword(s):  
Control Strategy ◽  
Phosphorus Removal ◽  
Batch Reactor ◽  
Past Research ◽  
P Uptake ◽  
Batch Reactors ◽  
Enhanced Biological Phosphorus Removal ◽  
Biological Phosphorus Removal ◽  
Aeration Time ◽  
Biological Phosphorus

A control strategy was developed for enhanced biological phosphorus removal (EBPR) in a Sequencing Batch Reactor (SBR). Unlike past research that focused on maximizing polyhdroxyalkanoate (PHA) formation during the anaerobic period, this study investigated some of the factors that govern aerobic PHA dynamics and its efficient regulation during phosphate (P) uptake. Influent COD, influent P, and the time for aeration were critical factors that governed PHA use and P uptake during aerated react. Unnecessary PHA oxidation (i.e., in the absence of extracellular P) occurred if the time for aerated react exceeded the time required for P uptake. By adjusting the aeration time to that required for P uptake, residual PHA was sustained in the SBR and excess phosphate uptake reaction potential (PRP) was generated for use during transient influent excursions in P. Unlike space oriented systems, the time for react is simply adjusted in the SBR. Because residual PHA is easily maintained once achieved, high influent COD events can be harnessed to increase or sustain excess PRP for management of expected variations in influent P.

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.

Conversion of Existing Primary Clarifiers According to the EASC Process for Biological Phosphorus Removal

1990 ◽  
Vol 22 (7-8) ◽  
pp. 45-51 ◽  
Author(s):  
R. Schönberger
Keyword(s):  
Phosphorus Removal ◽  
Municipal Wastewater ◽  
Operation Mode ◽  
Phosphorus Uptake ◽  
Treatment Plant ◽  
Municipal Wastewater Treatment ◽  
Biological Phosphorus Removal ◽  
Northern Germany ◽  
Start Up ◽  
Biological Phosphorus

At the end of 1988 a 22,000 p.e. municipal wastewater treatment plant in Northern Germany was converted to the EASC-biological phosphorus removal process. By simple modifications of the flow scheme of the plant, one of two existing primary clarifiers was converted to an anaerobic basin, into which both sewage and recycle sludge are fed. The supernatant as well as the sludge withdrawn from the bottom are discharged into the aeration basin. This operation mode achieves very good phosphorus uptake in the aeration basin. Since start up in November '88, the uptake-capacity increased continually, since April '89 phosphorus is removed down to concentrations of less than 1 mg/l PO4-P in the aeration basin. Due to an inadequate design and size of the existing final clarifier, phosphorus bleedback occurs and reduces removal efficiency. This bleedback could be minimized by either intensifying denitrification or reducing sludge detention time in the final clarifier.

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.

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