Effect of Sludge Type on Enhanced Biological Phosphorus Removal in Sequencing Batch Reactors

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.

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

Water Science & Technology ◽

10.2166/wst.2010.079 ◽

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.

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

Water Science & Technology ◽

10.2166/wst.2001.0135 ◽

2001 ◽

Vol 43 (3) ◽

pp. 183-189 ◽

Cited By ~ 11

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.

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Dynamics of Microbial Community Structure of and Enhanced Biological Phosphorus Removal by Aerobic Granules Cultivated on Propionate or Acetate

Applied and Environmental Microbiology ◽

10.1128/aem.05738-11 ◽

2011 ◽

Vol 77 (22) ◽

pp. 8041-8051 ◽

Cited By ~ 60

Author(s):

Graciela Gonzalez-Gil ◽

Christof Holliger

Keyword(s):

Phosphorus Removal ◽

Bubble Column ◽

Phosphate Removal ◽

Batch Reactors ◽

Type I ◽

Aerobic Granules ◽

Enhanced Biological Phosphorus Removal ◽

Biological Phosphorus Removal ◽

Content Type ◽

Biological Phosphorus

ABSTRACTAerobic granules are dense microbial aggregates with the potential to replace floccular sludge for the treatment of wastewaters. In bubble-column sequencing batch reactors, distinct microbial populations dominated propionate- and acetate-cultivated aerobic granules after 50 days of reactor operation when only carbon removal was detected. Propionate granules were dominated byZoogloea(40%),Acidovorax, andThiothrix, whereas acetate granules were mainly dominated byThiothrix(60%). Thereafter, an exponential increase in enhanced biological phosphorus removal (EBPR) activity was observed in the propionate granules, but a linear and erratic increase was detected in the acetate ones. BesidesAccumulibacterandCompetibacter, other bacterial populations found in both granules were associated withChloroflexusandAcidovorax. The EBPR activity in the propionate granules was high and stable, whereas EBPR in the acetate granules was erratic throughout the study and suffered from a deterioration period that could be readily reversed by inducing hydrolysis of polyphosphate in presumably saturatedAccumulibactercells. Using a newppk1gene-based dual terminal-restriction fragment length polymorphism (T-RFLP) approach revealed thatAccumulibacterdiversity was highest in the floccular sludge inoculum but that when granules were formed, propionate readily favored the dominance ofAccumulibactertype IIA. In contrast, acetate granules exhibited transient shifts between type I and type II before the granules were dominated byAccumulibactertype IIA. However,ppk1gene sequences from acetate granules clustered separately from those of propionate granules. Our data indicate that the mere presence ofAccumulibacteris not enough to have consistently high EBPR but that the type ofAccumulibacterdetermines the robustness of the phosphate removal process.

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Performance of enhanced biological phosphorus removal and population dynamics of phosphorus accumulating organisms in sludge-shifting sequencing batch reactors

Water Science & Technology ◽

10.2166/wst.2018.363 ◽

2018 ◽

Vol 78 (4) ◽

pp. 886-895 ◽

Cited By ~ 1

Author(s):

Yang Pan ◽

Wenquan Ruan ◽

Yong Huang ◽

Qianqian Chen ◽

Hengfeng Miao ◽

...

Keyword(s):

Removal Efficiency ◽

Phosphorus Removal ◽

Denaturing Gradient Gel Electrophoresis ◽

Batch Reactor ◽

Batch Reactors ◽

Enhanced Biological Phosphorus Removal ◽

Biological Phosphorus Removal ◽

High Concentration ◽

Gradient Gel Electrophoresis ◽

Biological Phosphorus

Abstract The sludge-shifting sequencing batch reactor (SBR) is an enhanced biological phosphorus removal (EBPR) process for wastewater treatment. In this study, the enrichment of phosphorus accumulating organisms (PAOs) will be attempted by using different high concentration of substrates. In sludge-shifting SBR, activated sludge can be continuously shifted from the bottom of SBR to anaerobic zone/selector, which contains high concentration of substrates, through an orderly reflux between the paralleled SBRs. Denaturing gradient gel electrophoresis (DGGE) methods were used to monitor microbial diversity in sludge. Fluorescence in situ hybridization (FISH) was used to determine the microbial population profile and distribution map under different sludge shifting volumes. The synthesis of intracellular polymers in this process was also analyzed. Phosphorus removal efficiency as high as 96% ± 1.3% was achieved under a sludge shifting ratio of 30%. Synthetic efficiencies of polyhydroxybutyrate (PHB) by PAOs were improved at high sludge shifting ratios. FISH results demonstrated that the population of PAOs in the process increased under properly sludge shifting ratio and it significantly improved phosphorus removal efficiency. Sequencing results indicated that determined sequences (11 OTUs) belonged to Proteobacterium, Actinobacteria and Firmicutes, Pseudomonas kuykendallii, which played an important role in the process of P removal.

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Role of extracellular exopolymers in biological phosphorus removal

Water Science & Technology ◽

10.2166/wst.2006.855 ◽

2006 ◽

Vol 54 (8) ◽

pp. 257-265 ◽

Cited By ~ 8

Author(s):

Y. Liu ◽

S. Yu ◽

G. Xue ◽

F. Zhao

Keyword(s):

Phosphorus Removal ◽

Energy Dispersive Spectrometry ◽

Phosphorus Content ◽

Carbon Sources ◽

Batch Reactors ◽

Sequencing Batch Reactors ◽

Biological Phosphorus Removal ◽

Key Factor ◽

Biological Phosphorus

Three sequencing batch reactors (SBRs) supplied with different carbon sources were investigated. The system supplied with glucose gained the best enhanced biological phosphorus removal (EBPR), although all of them were seeded from the same sludge. With the measurement of poly-β-hydroxyalkanoate (PHA) concentration, phosphorus content in sludge and extracellular exopolymers (EPs) with scanning electron microscopy (SEM) combined with energy dispersive spectrometry (EDS), it was found that the biosorption effect of EPs played an important role in phosphorus removal and that the amount of PHA at the end of anaerobic phase was not the only key factor to determine the following phosphorus removal efficiency.

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An ORP screening protocol for biological phosphorus removal in sequencing batch reactors

Canadian Journal of Civil Engineering ◽

10.1139/l95-035 ◽

1995 ◽

Vol 22 (2) ◽

pp. 260-269 ◽

Cited By ~ 4

Author(s):

D. G. Wareham ◽

K. J. Hall ◽

D. S. Mavinic

Keyword(s):

Carbon Storage ◽

Phosphorus Removal ◽

Reduction Potential ◽

Batch Reactors ◽

Sequencing Batch Reactors ◽

Biological Phosphorus Removal ◽

Oxidation Reduction ◽

Oxidation Reduction Potential ◽

Screening Protocol ◽

Biological Phosphorus

This research discusses two strategies for adding acetate to sequencing batch reactors operating as biological removal (Bio-P) systems. The control (fixed-time) reactor adds the acetate at a set time of 1 h 25 min, which is an assumed time for complete denitrification. The experimental (real-time) reactor adds the acetate when a computer detects the disappearance of nitrates, as indicated by a distinctive "breakpoint" or "kink" in the oxidation-reduction potential versus time profile. This control strategy is therefore based upon a known time for complete denitrification. The time-of-occurrence of the nitrate breakpoint is utilized in the development of a screening protocol for interpreting the behaviour (in terms of nitrate reactions) for reactors operating in biological phosphorus removal mode. The protocol involves categorizing the timing of the nitrate breakpoint into two groupings. A "failure" category corresponds to acetate being added prior to the breakpoint, because, in these cases, the acetate is used partially for denitrification and partially for Bio-P carbon storage. A "success" category corresponds to breakpoints occurring prior to the addition of acetate. In such cases, acetate is used solely for carbon storage by Bio-P organisms. Key words: oxidation-reduction potential, biological phosphorus removal, sequencing batch reactor, real-time computer control.

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Bioaugmentation of sequencing batch reactors for biological phosphorus removal: comparative rRNA sequence analysis and hybridization with oligonucleotide probes

Water Science & Technology ◽

10.2166/wst.1998.0697 ◽

1998 ◽

Vol 37 (4-5) ◽

pp. 469-473 ◽

Cited By ~ 7

Author(s):

Daniel B. Oerther ◽

James Danalewich ◽

Ebru Dulekgurgen ◽

Eric Leveque ◽

David L. Freedman ◽

...

Keyword(s):

Phosphorus Removal ◽

Laboratory Scale ◽

Batch Reactors ◽

Oligonucleotide Probes ◽

Sequencing Batch Reactors ◽

Biological Phosphorus Removal ◽

Start Up ◽

Pure Cultures ◽

Acinetobacter Spp ◽

Biological Phosphorus

Four laboratory-scale sequencing batch reactors (SBRs) were operated to evaluate whether bioaugmentation with Acinetobacter spp. can be used to improve start-up and performance of enhanced biological phosphorus removal (EBPR) systems. Two of the SBRs were bioaugmented during start-up by adding pure cultures of Acinetobacter spp., the third reactor received an amendment of activated sludge from a laboratory-scale EBPR system, and the fourth reactor, receiving no amendment, served as a control. Various chemical parameters were measured to monitor the performance of the four SBRS. Oligonucleotide probes of nested phylogenetic specificity were designed to quantify the contribution of Acinetobacter to EBPR. The probes were characterized for use in quantitative membrane hybridizations and fluorescent in situ hybridizations. Data from hybridizations with samples collected from the SBRs show declining levels of Acinetobacter spp. over the experiment. All four reactors achieved significant phosphorus removal and 90% nitrification after three days of operation. The results do not show a positive correlation between levels of Acinetobacter and successful EBPR.

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