Nutrient removal, microbial community and sludge settlement in anaerobic/aerobic sequencing batch reactors without enhanced biological phosphorus removal

2010 ◽  
Vol 61 (10) ◽  
pp. 2433-2441
Author(s):  
Guangxue Wu ◽  
Michael Rodgers
Keyword(s):  
Microbial Community ◽  
Nutrient Removal ◽  
Phosphorus Removal ◽  
Significant Proportion ◽  
Volume Index ◽  
Batch Reactors ◽  
Sequencing Batch Reactors ◽  
Enhanced Biological Phosphorus Removal ◽  
Biological Phosphorus Removal ◽  
Biological Phosphorus

Nutrient removal, microbial community and sludge settlement were examined in two 3-litre laboratory-scale anaerobic/aerobic sequencing batch reactors (SBRs). One SBR was operated at 10°C and the other SBR at 20°C. Different from conventional enhanced biological phosphorus removal, most of the soluble sodium acetate was removed in the aerobic phase and no organic carbon uptake or biological phosphorus release occurred in the anaerobic phase. In this type of anaerobic/aerobic SBR, the phosphorus removal and sludge settlement seemed to be unstable, and the dominant microorganism was Zoogloea sp. Although no excess biological phosphorus removal occurred, extracellular phosphorus precipitation contributed a significant proportion to total phosphorus removed. Sludge volume index decreased with increasing phosphorus contents in the biomass under all conditions. The functions of extracellular polymeric substances in sludge settlement and phosphorus removal depended on the environmental conditions applied.

The effect of volatile fatty acids on enhanced biological phosphorus removal and population structure in anaerobic/aerobic sequencing batch reactors

1997 ◽  
Vol 35 (1) ◽  
pp. 153-160 ◽  
Author(s):  
Andrew Amis Randall ◽  
Larry D. Benefield ◽  
William E. Hill ◽  
Jean-Paul Nicol ◽  
Gerald K. Boman ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Phosphorus Removal ◽  
Volatile Fatty Acids ◽  
Batch Reactors ◽  
Sequencing Batch Reactors ◽  
Enhanced Biological Phosphorus Removal ◽  
Biological Phosphorus Removal ◽  
Slow Growth Rate ◽  
Biological Phosphorus ◽  
State Nature

Three anaerobic/aerobic sequencing batch reactors (SBRs) were operated for 5 1/2 years. Volatile fatty acids (VFAs) in influent wastewater for two of the SBRs (the Glucose 1 and 2 SBRs) resulted in optimization of enhanced biological phosphorus removal (EBPR), and a bacterial population capable of increasing phosphorus (P) removals in response to increased VFA or P concentration. Another SBR not receiving VFAs (the Starch SBR) showed marginal EBPR and was incapable of either response. All three anaerobic/aerobic sequencing batch reactors (SBRs) showed bounded oscillations in P removal that did not correspond to any operational or environmental change. The oscillations were probably associated with interspecies population dynamics intensified due to the periodic, unsteady-state, nature of the SBR process. The glucose SBRs also showed an additional type of variability associated with EBPR, probably from competition between poly-P and “G” bacteria for readily available substrate (i.e. glucose, VFAs) during anaerobiosis. The predominant bacterial isolates from the glucose SBRs were Pseudomonas and Bacillus while Aeromonas was isolated most frequently from the Starch SBR. The relatively slow growth rate of Pseudomonas may have contributed to the high variability of EBPR observed. Fractal analysis indicated overall variability may have been chaotic, but was inconclusive.

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.

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.

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