The Importance of the Acidogenic Microflora in Biological Phosphorus Removal

1985 ◽  
Vol 17 (11-12) ◽  
pp. 199-212 ◽  
Author(s):  
M. Meganck ◽  
D. Malnou ◽  
P. Le Flohic ◽  
G. M. Faup ◽  
J. M. Rovel

Laboratory and semi-industrial scale pilot plant experiments were carried out to study the possibility of simultaneous biological nitrogen and phosphorus removal under European winter temperature conditions. Whereas nitrogen removal requires very long aerated sludge ages, phosphorus removal seems to be somewhat inhibited by the low sludge loadings. Experiments with fatty acid addition to the influent wastewater have shown the acidogenic phase to be the step that was most affected by these low load conditions. The phosphorus release and uptake mechanism in itself may be slowed down by lower temperatures, but still has some activity. A microbiological study of the organisms in the sludge was undertaken in order to discover which organisms were responsible for the different steps in the phosphorus removal mechanism.

2006 ◽  
Vol 53 (3) ◽  
pp. 53-60 ◽  
Author(s):  
Y. Annaka ◽  
Y. Hamamoto ◽  
M. Akatsu ◽  
K. Maruyama ◽  
S. Oota ◽  
...  

To reduce MBR O&M costs, a new MBR process that conducts efficient simultaneous biological nitrogen and phosphorus removal (BNR) was developed. In the development of this process, various approaches were taken, including reduction of power demand, chemical consumption and sludge disposal costs. To address power demand reductions, air supply requirements for membrane cleaning were reduced. The process adopted an improved membrane that requires less air for cleaning than conventional membranes. It also introduced cyclic aeration, which alternately supplies washing air to the two series of membrane units. Adoption of biological phosphorus removal eliminated chemical costs for phosphorus removal and contributed to the reduction of sludge disposal costs. By combining these technologies, compared to conventional MBR processes, an approximately 27% reduction in O&M costs was achieved.


Author(s):  
Giedre Vaboliene ◽  
Algirdas Bronislovas Matuzevičius

Nitrogen and phosphorus removal is necessary to avoid eutrophication of water bodies when treated wastewater is outlet to slowly flowing water bodies or recycled as technological water. The “BioBalance” technology as the latest way of nitrogen and phosphorus removal was applied at Utena Wastewater Treatment Plant. Composition of wastewater has an impact on biological phosphorus removal, particularly the ratio of biochemical oxygen demand and total phosphorus (BOD7/Total-P) in wastewater after mechanical treatment. Nitrates in the anaerobic zone can have a negative effect on biological phosphorus removal. Consequently, it is necessary to evaluate the impact of the mentioned factors on biological nitrogen and phosphorus removal. Biological nitrogen and phosphorus removal was evaluated and compared by using the “BioBalance” technology for biological nitrogen and phosphorus removal and technology before reconstruction during this investigation. The correlation regressive analysis of the biochemical oxygen demand and total phosphorus (BOD7/Total‐P) after mechanical treatment and the total phosphorus concentration in the effluent was evaluated. The correlation regressive analysis of nitrates in an anaerobic zone on the aeration tank and the efficiency of phosphorus removal was also evaluated.


1983 ◽  
Vol 15 (3-4) ◽  
pp. 1-13 ◽  
Author(s):  
James L Barnard

This paper briefly summarizes the early work on phosphorus removal in activated sludge plants in the U.S.A. and observed that such removals only occurred in low SRT plants of the plug flow type and in the Phostrip plants, neither designed for full nitrification. The discovery of simultaneous nitrogen and phosphorus removal, as well as full-scale experiments are discussed. The Phoredox process was proposed utilizing internal recycling for the removal of nitrates and an anaerobic first stage in which the incoming feed is used to obtain the necessary anaerobic conditions, essential as a conditioning step for the uptake of phosphorus. Proposed mechanisms are discussed.


2004 ◽  
Vol 50 (10) ◽  
pp. 163-170 ◽  
Author(s):  
R.J. Zeng ◽  
R. Lemaire ◽  
Z. Yuan ◽  
J. Keller

Simultaneous nitrification and denitrification (SND) via the nitrite pathway and anaerobic–anoxic enhanced biological phosphorus removal (EBPR) are two processes that can significantly reduce the COD demand for nitrogen and phosphorus removal. The combination of these two processes has the potential of achieving simultaneous nitrogen and phosphorus removal with a minimal requirement for COD. A lab-scale sequencing batch reactor (SBR) was operated in alternating anaerobic–aerobic mode with a low dissolved oxygen concentration (DO, 0.5 mg/L) during the aerobic period, and was demonstrated to accomplish nitrification, denitrification and phosphorus removal. Under anaerobic conditions, COD was taken up and converted to polyhydroxyalkanoates (PHA), accompanied with phosphorus release. In the subsequent aerobic stage, PHA was oxidized and phosphorus was taken up to less than 0.5 mg/L at the end of the cycle. Ammonia was also oxidised during the aerobic period, but without accumulation of nitrite or nitrate in the system, indicating the occurrence of simultaneous nitrification and denitrification. However, off-gas analysis found that the final denitrification product was mainly nitrous oxide (N2O) not N2. Further experimental results demonstrated that nitrogen removal was via nitrite, not nitrate. These experiments also showed that denitrifying glycogen-accumulating organisms rather than denitrifying polyphosphate-accumulating organisms were responsible for the denitrification activity.


2006 ◽  
Vol 53 (9) ◽  
pp. 169-175 ◽  
Author(s):  
K. Hamada ◽  
T. Kuba ◽  
V. Torrico ◽  
M. Okazaki ◽  
T. Kusuda

A shortage of organic substances (COD) may cause problems for biological nutrient removal, that is, lower influent COD concentration leads to lower nutrient removal rates. Biological phosphorus removal and denitrification are reactions in which COD is indispensable. As for biological simultaneous nitrogen and phosphorus removal systems, a competition problem of COD utilisation between polyphosphate accumulating organisms (PAOs) and non-polyphosphate-accumulating denitrifiers is not avoided. From the viewpoint of effective utilisation of limited influent COD, denitrifying phosphorus-removing organisms (DN-PAOs) can be effective. In this study, DN-PAOs activities in modified UCT (pre-denitrification process) and DEPHANOX (post-denitrification ptocess) wastewater treatments were compared. In conclusion, the post-denitrification systems can use influent COD more effectively and have higher nutrient removal efficiencies than the conventional pre-denitrification systems.


1993 ◽  
Vol 27 (9) ◽  
pp. 105-113
Author(s):  
G. Petersen ◽  
H. Nour El-Din ◽  
E. Bundgaard

Oxidation ditcb systems for waste water treatment at various demands for effluent quality with regard to BOD, nitrogen and phosphorus are presented. Simple design for only BOD-removal and nitrification as well as designs for advanced treatment including biological nitrogen and biological phosphorus removal are presented, and full scale results from more than 15 years of operation are shown. The simple design and price competitive construction can none the less produce effluent qualities below 15 mg BOD/l, 8 mg N/l and 1.5 mg P/l if the right oxidation ditcb combination is used.


1996 ◽  
Vol 34 (1-2) ◽  
pp. 221-228 ◽  
Author(s):  
Gakuji Kurata ◽  
Kazushi Tsumura ◽  
Syoichiro Nakamura ◽  
Michio Kuwahara ◽  
Akio Sato ◽  
...  

In existing wastewater treatment plants that employ biological nitrogen and phosphorus removal processes, a low concentration of organic substrates in the influent wastewater has a destabilizing effect on the phosphorus removal process. Many efforts have been made to combat this problem, including reconstructing the process flow and improving operation and control systems. However, because the mechanism used for biological phosphorus removal is complex, it is difficult to establish effective empirical methods. For this paper, we constructed a simulator for the wastewater treatment process and tried to improve on current procedures, focusing on the planning, execution, and evaluation of methods of retrofitting existing WWTP with equipment for biological nutrient removal. The Shinnanyo WWTP uses the anaerobic/aerobic activated sludge process to remove nitrogen and phosphorus biologically. At this plant, however, the influent wastwwater has an insufficient concentration of organic substrates, thus decreasing the efficiency of the biological phosphorus removal. An analysis of organic consumption in the reaction tank on the simulation suggested that injecting primary sludge into the reaction tank would increase the efficiency of phosphorus removal process. Full scale experiments conducted at the plant verified the efficiency of this method. In addition, by shortening the A-SRT, ensuring that nitrification is not negatively affected, the efficiency of the nitrogen and phosphorus removal was significantly improved.


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