Biological denitrifying phosphorus removal in SBR: effect of added nitrate concentration and sludge retention time

2001 ◽  
Vol 43 (3) ◽  
pp. 191-194 ◽  
Author(s):  
M. Merzouki ◽  
N. Bernet ◽  
J.-P. Deigenès ◽  
R. Moletta ◽  
M. Benlemlih
Keyword(s):  
Retention Time ◽  
Phosphorus Removal ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Synthetic Wastewater ◽  
Biological Phosphorus Removal ◽  
Denitrifying Phosphorus Removal ◽  
Sludge Retention Time ◽  
Two Parameters ◽  
Biological Phosphorus

Optimizing anoxic biological phosphorus removal in the anaerobic-anoxic sequencing batch reactor (A2 SBR) was observed to depend on two parameters: the amount of added nitrate and the sludge retention time (SRT). The concentration of 120 mg N-NO3 · l-1 in the anoxic medium and the SRT of 15 days were determined as optimal for a complete phosphorus removal in the A2 SBR. The reactor was supplied with synthetic wastewater containing 800 mg COD.l-1 acetic acid, 240 mg N-NH4·l-1 and 30 mg P-PO4·l-1. This study was completed by microscopic observations which revealed three morphological types of phosphate-accumulating bacteria (PAB).

Biological phosphorus removal with nitrite as election acceptor

2006 ◽  
Vol 53 (9) ◽  
pp. 185-191 ◽  
Author(s):  
Xiaoling Zhang ◽  
Zhiying Wang ◽  
Qing Zhao
Keyword(s):  
Phosphorus Removal ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Granular Sludge ◽  
Biological Phosphorus Removal ◽  
Denitrifying Phosphorus Removal ◽  
Operational Conditions ◽  
Feed Mode ◽  
Continuous Feed ◽  
Biological Phosphorus

Biological phosphorus removal was studied in a sequencing batch reactor (SBR). The results showed that nitrite could be used as electron acceptor in denitrifying phosphorus removal. Feed mode of nitrite had significant influence on denitrifying phosphorus removal. Anoxic phosphorus assimilation rate could reach 10.44 mgP/gSS.h and the percentage of anoxic phosphorus assimilation amount was more than 97% with continuous feed mode. Granular sludge with denitrifying phosphorus removal activity was found in the SBR. The effects of different operational conditions, such as COD loading, settling time, HRT etc., on the formation of granules were also studied.

Biological Phosphorus Removal from Wastewater by Anaerobic-Anoxic Sequencing Batch Reactor

1993 ◽  
Vol 27 (5-6) ◽  
pp. 241-252 ◽  
Author(s):  
T. Kuba ◽  
G. Smolders ◽  
M. C. M. van Loosdrecht ◽  
J. J. Heijnen
Keyword(s):  
Electron Acceptor ◽  
Phosphorus Removal ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Phosphorus Uptake ◽  
Phosphorus Release ◽  
Synthetic Wastewater ◽  
Biological Phosphorus Removal ◽  
Removal Processes ◽  
Biological Phosphorus

In this study an anaerobic-anoxic SBR (sequencing batch reactor) was used in order to investigate the possibility of phosphorus removal utilizing nitrate as an electron acceptor, instead of oxygen in biological phosphorus removal processes. The reactor was supplied with synthetic wastewater, in which acetic acid (HAc) and phosphate were added at concentrations of 400 mg-COD/l and 15 mg-P/l. A conventional anaerobic-aerobic SBR was also operated to compare with the anaerobic-anoxic SBR. The objectives of this research are to examine (i) feasibility and stability of the systems, (ii) kinetics and stoichiometry of phosphorus release and uptake. The anaerobic-anoxic SBR operation resulted in a stable phosphorus removal and accumulation of phosphorus removing bacteria using nitrate as an electron acceptor. Immediately after inoculation from a phosphorus removing plant (Renpho system) phosphorus uptake was observed, indicating that phosphorus removing bacteria which are able to utilize nitrate were already present in conventional phosphorus removing sludge. Comparison of stoichiometry and kinetics with the conventional anaerobic-aerobic SBR system shows a similar potential for phosphorus removal by denitrifying organisms. Therefore in the design of phosphorus removal processes one should not be afraid of nitrate, but use it.

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.

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