Comparison of nutrient removal efficiency between pre- and post-denitrification wastewater treatments

2006 ◽  
Vol 53 (9) ◽  
pp. 169-175 ◽  
Author(s):  
K. Hamada ◽  
T. Kuba ◽  
V. Torrico ◽  
M. Okazaki ◽  
T. Kusuda
Keyword(s):  
Nutrient Removal ◽  
Phosphorus Removal ◽  
Biological Nutrient Removal ◽  
Biological Phosphorus Removal ◽  
Nitrogen And Phosphorus ◽  
Nitrogen And Phosphorus Removal ◽  
Nutrient Removal Efficiency ◽  
Polyphosphate Accumulating Organisms ◽  
Biological Phosphorus ◽  
Denitrification Process

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.

Retrofit of biological nutrient removal process assisted by numerical simulation with activated sludge model no. 2

1996 ◽  
Vol 34 (1-2) ◽  
pp. 221-228 ◽  
Author(s):  
Gakuji Kurata ◽  
Kazushi Tsumura ◽  
Syoichiro Nakamura ◽  
Michio Kuwahara ◽  
Akio Sato ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Nutrient Removal ◽  
Phosphorus Removal ◽  
Biological Nutrient Removal ◽  
Organic Substrates ◽  
Biological Phosphorus Removal ◽  
Nitrogen And Phosphorus ◽  
Nitrogen And Phosphorus Removal ◽  
Removal Process ◽  
Biological Phosphorus

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.

Practical Experience with Biological Phosphorus Removal Plants in Johannesburg

1983 ◽  
Vol 15 (3-4) ◽  
pp. 233-259 ◽  
Author(s):  
A R Pitman ◽  
S L V Venter ◽  
H A Nicholls
Keyword(s):  
Activated Sludge ◽  
Nutrient Removal ◽  
Phosphorus Removal ◽  
Operating Experience ◽  
Practical Experience ◽  
Biological Nutrient Removal ◽  
Biological Phosphorus Removal ◽  
Factors Affecting ◽  
Process Improvements ◽  
Biological Phosphorus

This paper describes three years operating experience with two full-scale biological nutrient removal activated sludge plants. Factors affecting biological phosphorus removal are highlighted and possible process improvements suggested.

Background to Biological Phosphorus Removal

1983 ◽  
Vol 15 (3-4) ◽  
pp. 1-13 ◽  
Author(s):  
James L Barnard
Keyword(s):  
Activated Sludge ◽  
Phosphorus Removal ◽  
Plug Flow ◽  
Full Scale ◽  
Biological Phosphorus Removal ◽  
Anaerobic Conditions ◽  
Paper Briefly ◽  
Nitrogen And Phosphorus ◽  
Nitrogen And Phosphorus Removal ◽  
Biological Phosphorus

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.

Development of MBR with reduced operational and maintenance costs

2006 ◽  
Vol 53 (3) ◽  
pp. 53-60 ◽  
Author(s):  
Y. Annaka ◽  
Y. Hamamoto ◽  
M. Akatsu ◽  
K. Maruyama ◽  
S. Oota ◽  
...  
Keyword(s):  
Phosphorus Removal ◽  
Power Demand ◽  
Biological Phosphorus Removal ◽  
Nitrogen And Phosphorus ◽  
Nitrogen And Phosphorus Removal ◽  
Membrane Cleaning ◽  
Sludge Disposal ◽  
Air Supply ◽  
Biological Nitrogen ◽  
Biological Phosphorus

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.

Simultaneous removal of organic and strong nitrogen from sewage in a pilot-scale BNR process supplemented with food waste

2004 ◽  
Vol 49 (5-6) ◽  
pp. 257-264 ◽  
Author(s):  
S.R. Chae ◽  
S.H. Lee ◽  
J.O. Kim ◽  
B.C. Paik ◽  
Y.C. Song ◽  
...  
Keyword(s):  
Carbon Source ◽  
Food Waste ◽  
Nutrient Removal ◽  
Phosphorus Removal ◽  
Pilot Scale ◽  
Biological Nutrient Removal ◽  
Biological Phosphorus Removal ◽  
External Carbon Source ◽  
N Removal ◽  
Biological Phosphorus

As the sewerage system is incomplete, sewage in Korea lacks easily biodegradable organics for nutrient removal. In this country, about 11,400 tons of food waste of high organic materials is produced daily. Therefore, the potential of food waste as an external carbon source was examined in a pilot-scale BNR (biological nutrient removal) process for a half year. It was found that as the supply of the external carbon increased, the average removal efficiencies of T-N (total nitrogen) and T-P (total phosphorus) increased from 53% and 55% to 97% and 93%, respectively. VFAs (volatile fatty acids) concentration of the external carbon source strongly affected denitrification efficiency and EBPR (enhanced biological phosphorus removal) activity. Biological phosphorus removal was increased to 93% when T-N removal efficiency increased from 78% to 97%. In this study, several kinds of PHAs (poly-hydroxyalkanoates) in cells were observed. The observed PHAs was composed of 37% 3HB (poly-3- hydroxybutyrate), 47% 3HV (poly-3-hydroxyvalerate), 9% 3HH (poly-3-hydroxyhexanoate), 5% 3HO (poly-3-hydroxyoctanoate), and 2% 3HD (poly-3-hydroxydecanoate).

Evaluation of combined chemical and biological nutrient removal

1996 ◽  
Vol 34 (1-2) ◽  
pp. 285-292 ◽  
Author(s):  
P. R. Thomas ◽  
D. Allen ◽  
D. L. McGregor
Keyword(s):  
Total Phosphorus ◽  
Nutrient Removal ◽  
Phosphorus Removal ◽  
Treatment Plant ◽  
Biological Nutrient Removal ◽  
Biological Phosphorus Removal ◽  
Minor Variation ◽  
Plant Trials ◽  
A Minor ◽  
Biological Phosphorus

This study was undertaken to optimise phosphorus removal by incorporating a chemical dosing facility in an existing biological nutrient removal activated sludge plant at Albury in Australia. Results of pilot plant trials and jar tests indicated that both alum and ferric chloride successfully reduced the orthophosphate concentrations with only a minor variation in the chemical costs. However, alum was chosen as the preferred chemical for use in the full-scale plant and tests showed that alum precipitation combined with biological nutrient removal lowered the orthophosphate (ortho-P) concentrations to as low as 0.01 mg/L with average total phosphorus (total-P) levels of around 0.5 mg/L. It is concluded that maximising total phosphorus removal in the treatment plant would require optimising biological phosphorus removal, applying correct chemical dosages to varying mixed liquor orthophosphate concentrations, adequate mixing, suitable pH values and minimising suspended solids in the clarifier effluent.

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