The effect of nitrite on aerobic phosphate uptake and denitrifying activity of phosphate-accumulating organisms

2006 ◽  
Vol 53 (6) ◽  
pp. 21-27 ◽  
Author(s):  
Y. Yoshida ◽  
K. Takahashi ◽  
T. Saito ◽  
K. Tanaka
Keyword(s):  
Phosphorus Removal ◽  
Sequencing Batch Reactor ◽  
Municipal Wastewater ◽  
Phosphate Uptake ◽  
Batch Reactor ◽  
Biological Phosphorus Removal ◽  
Interesting Observation ◽  
Batch Tests ◽  
Uptake Activity ◽  
Biological Phosphorus

An anaerobic/aerobic/anoxic/aerobic sequencing batch reactor (SBR) was operated with municipal wastewater to investigate the effect of nitrite on biological phosphorus removal (BPR). When nitrite accumulated, aerobic phosphate uptake activity significantly decreased and, in case of hard exposure to nitrite, BPR severely deteriorated. The interesting observation was that the relative anoxic activity of phosphate accumulating organisms (PAOs) increased after nitrite exposure. Moreover batch tests of aerobic phosphate uptake in the presence/absence of nitrite indicated that PAOs with the higher relative anoxic activity are less sensitive to nitrite exposure. From these results, we concluded that BPR is sensitive to nitrite exposure, but BPR containing PAOs with the higher relative anoxic activity is possibly more stable against nitrite than BPR containing PAOs with the lower relative anoxic activity.

Effect of nitrate on phosphorus release in biological phosphorus removal systems

1994 ◽  
Vol 30 (6) ◽  
pp. 263-269 ◽  
Author(s):  
T. Kuba ◽  
A. Wachtmeister ◽  
M. C. M. van Loosdrecht ◽  
J. J. Heijnen
Keyword(s):  
Phosphorus Removal ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Phosphorus Uptake ◽  
Reducing Power ◽  
Phosphorus Release ◽  
Biological Phosphorus Removal ◽  
Batch Tests ◽  
Polyphosphate Degradation ◽  
Biological Phosphorus

The effect of nitrate on phosphorus release by biological phosphorus removing organisms has been studied. Denitrifying (DPB) or aerobic phosphorus removing bacteria were enriched in an anaerobic-anoxic or anaerobic-aerobic sequencing batch reactor (SBR). The enrichment sludges were used in batch tests, in which the effect of simultaneous presence of substrate (HAc) and nitrate was studied on the phosphorus release. It could be concluded that a reduction of the phosphorus release by nitrate in biological phosphorus removal systems is partly due to the presence of DPB, which utilize HAc for denitrification, not for phosphorus release. PHB (poly-β-hydroxybutyrate) was always produced and phosphorus was released by DPB sludge when nitrate and HAc were simultaneously present. The reducing power (NADH2) and the energy (ATP) for this process seemed to be obtained from HAc oxidation by nitrate as well as from polyphosphate degradation. After removal of the HAc, PHB degradation and phosphorus uptake occurred.

The influence of different substrates on enhanced biological phosphorus removal in a sequencing batch reactor

1997 ◽  
Vol 35 (1) ◽  
pp. 75-80 ◽  
Author(s):  
R. Tasli ◽  
N. Artan ◽  
D. Orhon
Keyword(s):  
Phosphorus Removal ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
The Other ◽  
Organic Substrates ◽  
Relative Importance ◽  
Enhanced Biological Phosphorus Removal ◽  
Biological Phosphorus Removal ◽  
Batch Tests ◽  
Biological Phosphorus

All models of enhanced biological phosphorus removal (EBPR) define fermentable readily biodegradable substrate, without emphasizing the significance of its composition and the relative importance of different substrates. On the other hand, it is also known that substrates like glucose may be utilized without requiring poly-P energy, a phenomenon which deteriorates the EBPR performance. This paper reports an experimental study evaluating the effect of different organic substrates and their combinations on EBPR, in a sequencing batch reactor. Experimental data show that the EBPR efficiency is significantly affected by the increase of the glucose fraction in the feed, due to the probable dominance of G bacteria. Results of anaerobic batch tests also support this evaluation.

Bacteria and Protozoa Population Dynamics in Biological Phosphate Removal Systems

1994 ◽  
Vol 29 (7) ◽  
pp. 109-117 ◽  
Author(s):  
J. S. Čech ◽  
P. Hartman ◽  
M. Macek
Keyword(s):  
Population Dynamics ◽  
Phosphorus Removal ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Sole Source ◽  
Phosphate Removal ◽  
Enhanced Biological Phosphorus Removal ◽  
Biological Phosphorus Removal ◽  
System Collapse ◽  
Biological Phosphorus

Population dynamics of polyphosphate-accumulating bacteria (PP bacteria) was studied in a laboratory sequencing batch reactor simulating anaerobic-oxic sludge system. The competition between PP bacteria and another microorganism (“G bacteria”) for anaerobic-oxic utilization of acetate as the sole source of organic carbon was observed. The competition was found to be seriously influenced by protozoan and metazoan grazing: Predation-resistant “G bacteria” forming large compact flocs outcompeted PP bacteria. Several breakdowns of enhanced biological phosphorus removal were observed. The first one was related to the development of an euglenid flagellate Entosiphon sulcatus and attached ciliates Vorticella microstoma and V. campanula. The second system collapse was connected with a rapid proliferation of rotifers. An alternative-prey predation was thought to be a mechanism of PP bacteria elimination.

Phosphorus removal from nightsoil with sequencing batch reactor (SBR)

1997 ◽  
Vol 36 (12) ◽  
pp. 55-60 ◽  
Author(s):  
S. W. Oa ◽  
E. Choi
Keyword(s):  
Chemical Reactions ◽  
Phosphorus Removal ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Chemical Precipitation ◽  
Phosphorus Release ◽  
Biological Nutrient Removal ◽  
Biological Phosphorus Removal ◽  
P Fractionation ◽  
Biological Phosphorus

Phosphorus removal characteristics are rather complicated in a highly nitrogenous waste like nightsoil under treatment with SBR (sequencing batch reactor). It was found that the increased pH due to denitrification in anaerobic period stimulated chemical precipitation of phosphorus as struvite and hydroxyapatite, and the depressed pH due to nitrification in the aerobic period dissolved the previously formed precipitates. Phosphate accumulating organisms (PAO) worked as in the ordinary BNR (biological nutrient removal) systems regardless of the chemical reactions, but the chemical reactions masked the biological phosphorus release and uptake reactions. About 36% of phosphorus applied was removed biologically in polyphosphate granules. P-fractionation of sludges confirmed this phenomenon. Biological phosphorus removal could be increased with the increased anaerobic period. The morphological types of phosphorus precipitates were examined by SEM in combination with x-ray diffraction.

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