Development and optimization of a sequencing batch reactor for nitrogen and phosphorus removal from abattoir wastewater to meet irrigation standards

2010 ◽  
Vol 61 (8) ◽  
pp. 2105-2112 ◽  
Author(s):  
Maite Pijuan ◽  
Zhiguo Yuan

A sequencing batch reactor (SBR) was used for the treatment of abattoir wastewater to produce effluent with desirable nitrogen and phosphorus levels for irrigation. The SBR cycle consisted of an anaerobic phase with wastewater feeding, a relatively short aerobic period (allowing full ammonium oxidation), a second anoxic period with feeding, followed by settling and decanting. This design of operation allowed biological nitrification and denitrification via nitrite, and therefore with reduced demand for aeration and COD for nitrogen removal. The design also allowed ammonium, rather than oxidized nitrogen, being the primary nitrogen species in the effluent. Biological phosphorus removal was also achieved, with an effluent level desirable for irrigation. A high-level of nitrite accumulation (40 mg N/L) in the reactor caused inhibition to the biological P uptake. This problem was solved through process optimization. The cycle time of the SBR was reduced, with the wastewater load per cycle also reduced, while the daily hydraulic loading maintained. This modification proved to be an effective method to ensure reliable N and P removal. N2O accumulation was measured in two experiments simulating the anoxic phase of the SBR and using nitrite and nitrate respectively as electron donors. The estimated N2O emissions for both experiments were very low.

1994 ◽  
Vol 30 (6) ◽  
pp. 303-313 ◽  
Author(s):  
G. Bortone ◽  
F. Malaspina ◽  
L. Stante ◽  
A. Tilche

An Anaerobic/Anoxic Sequencing Batch Reactor (A/A SBR) with separated batch biofilm nitrification was tested for nutrient removal against a five step Anaerobic-anoxic/Oxic SBR (A/O SBR). Piggery wastewater, particularly challenging for its low COD/N ratio, was used as feed. After feeding, the A/A SBR ran under anaerobic conditions for organic carbon sequestering and phosphorus removal. A settling phase was allowed to separate an ammonia-rich supernatant to be nitrified in a external biofilm reactor. The nitrified effluent returned to the A/A SBR where nitrates were removed, being used as final electron acceptors for luxury P-uptake and organic carbon oxidation. A/A SBR showed very good N and P removal capacities with excellent sludge settling properties. On the other hand, organic carbon removal efficiency with nitrate was lower than with oxygen. Batch biofilm nitrification was very effective, with very high nitrification rates. Presence of poly-P bacteria in the A/A SBR sludge was assessed through microscopic observation and from the high cellular poly-phosphate content.


2008 ◽  
Vol 20 (3) ◽  
pp. 339-350 ◽  
Author(s):  
Romain Lemaire ◽  
Zhiguo Yuan ◽  
Nicolas Bernet ◽  
Marcelino Marcos ◽  
Gulsum Yilmaz ◽  
...  

2004 ◽  
Vol 48 (11-12) ◽  
pp. 371-376 ◽  
Author(s):  
Ufuk Altinbaş ◽  
Izzet Öztürk

Removal efficiency of TOC ranged between 86–89% in an intermittently aerated reactor. High efficiency in TKN removal and nitrification was found at lower applied load or longer retention time such as 2 days. TKN removal and nitrification efficiency was found to be 17–96% and 35–99% respectively. Through examination and comparison of the removal efficiencies, the stability of nitrification/denitrification and the biological phosphorus removal it was found that the sequencing batch feeding system gave a higher performance in total nitrogen and phosphorus removals. In the SBR reactor, nitrogen removal efficiency was mainly controlled by organic loading. Nitrification efficiency ranged between 31–56%. Nearly complete denitrification was observed in the sequencing batch reactor.


1994 ◽  
Vol 29 (7) ◽  
pp. 109-117 ◽  
Author(s):  
J. S. Čech ◽  
P. Hartman ◽  
M. Macek

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.


2001 ◽  
Vol 43 (3) ◽  
pp. 183-189 ◽  
Author(s):  
C. Y. Dassanayake ◽  
R. L. Irvine

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.


2012 ◽  
Vol 65 (5) ◽  
pp. 840-844 ◽  
Author(s):  
D. Wu ◽  
T. Hao ◽  
H. Lu ◽  
H. K. Chui ◽  
M. C. M. van Loosdrecht ◽  
...  

This study explored a sulfur cycle-associated biological phosphorus (P) removal process in a covered and non-aerated sequencing batch reactor (SBR) fed with volatile fatty acid (VFA) and sulfate separately. During the 60-day start-up, both phosphate release and uptake rates increased, while poly-phosphate cyclically increased and decreased accordingly. The P-release and P-uptake rates were associated with VFA uptake and sulfate reduction. The average ratio of potassium to phosphate during the P-uptake and P-release was also determined to be 0.29–0.31 mol K/mol P, which is close to a reported value (0.33) for biological phosphorus removal. All this evidence confirmed there was biological P removal in this reactor, in which metabolism could be different from conventional biological P removal.


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