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 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).

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.

Cold Climate Sequencing Batch Reactor Biological Phosphorus Removal – Results 1991-92

1993 ◽  
Vol 28 (10) ◽  
pp. 275-282 ◽  
Author(s):  
S. Marklund
Keyword(s):  
Cycle Time ◽  
Phosphorus Removal ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Treatment Plant ◽  
Cold Climate ◽  
Small Scale ◽  
Aeration Tank ◽  
Biological Phosphorus Removal ◽  
Biological Phosphorus

The aeration tank in a small scale wastewater treatment plant was converted to a sequencing batch reactor (SBR) with a maximum volume of approx. 27 m3. The main purpose of this study was to examine low temperature biological phosphorus removal (BPR). The wastewater temperature varied during the study between 3 and 8°C, with a water temperature at or below 5°C during 7 months of the year. The SBR unit has been in operation from the end of 1989, the study period discussed here covered July 1991 - December 1992. SBR cycle time was varied between 6 and 12 hours, giving a total daily treatment capacity of between 18 and 36 m3. The influent biological oxygen demand - 7 days (BOD7) levels varied between 88 and 165 mg/l. Corresponding phosphorus levels were between 3.10 and 9.55 mg/l The mean effluent level of phosphorus was 1.57 mg/l and the BOD7 value was 23 mg/l. This gives a mean total phosphorus reduction of 74% and a BOD7 reduction of 81 %. During the study, mean supernatant suspended solids (SS) levels were quite high, at around 36 mg/l. This high SS level contributed a major part of both outlet phosphorus as well as BOD7 value. Effluent soluble values for phosphorus and BOD7 were 0.79 mg/l and 9 mg/l. The supernatant SS component of BOD7 and phosphorus increased at lower temperatures. It was not possible to reduce or balance this increase by increased cycle time or increased settling time within the maximum cycle time available (12 hours). Stable low supernatant phosphorus and BOD7 levels are thus to a large degree controlled by the effluent SS level. A maximum of 20 mg/l supernatant SS is necessary to reach target supernatant values of less than 1 mg/l of phosphorus and 15 mg/l of BOD7.

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