Mainstream partial nitritation and anammox in a 200,000 m3/day activated sludge process in Singapore: scale-down by using laboratory fed-batch reactor

2016 ◽  
Vol 74 (1) ◽  
pp. 48-56 ◽  
Author(s):  
Cao Yeshi ◽  
Kwok Bee Hong ◽  
Mark C. M. van Loosdrecht ◽  
Glen T. Daigger ◽  
Png Hui Yi ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Batch Reactor ◽  
Oxygen Demand ◽  
Activated Sludge Process ◽  
Biological Phosphorus Removal ◽  
Fed Batch ◽  
Partial Nitritation ◽  
Scale Down ◽  
Laboratory Reactor ◽  
Biological Phosphorus

A laboratory fed-batch reactor has been used to study under controlled conditions the performance of partial nitritation/anammox for the 200,000 m3/day step-feed activated sludge process at the Changi Water Reclamation Plant, Singapore. The similarity of the concentrations of NH4, NO2, NO3, PO4, suspended chemical oxygen demand (sCOD), pH, and alkalinity (ALK) between the on-site process and laboratory reactor illustrates that the laboratory fed-batch reactor can be used to simulate the site performance. The performance of the reactor fed by primary effluent illustrated the existence of anammox and heterotrophic denitrification and apparent excessive biological phosphorus removal as observed from the site. The performance of the reactor fed by final effluent proved the presence of anammox process on site. Both the laboratory reactor and on-site process showed that higher influent 5-day biochemical oxygen demand/total nitrogen (BOD5/TN) (COD/TN) ratio increases the nitrogen removal efficiency of the process.

pH: Keyfactor in the Biological Phosphorus Removal Process

1994 ◽  
Vol 29 (7) ◽  
pp. 71-74 ◽  
Author(s):  
G. J. F. Smolders ◽  
M. C. M. van Loosdrecht ◽  
J. J. Heijnen
Keyword(s):  
Activated Sludge ◽  
Phosphorus Removal ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Glycogen Metabolism ◽  
Activated Sludge Process ◽  
Biological Phosphorus Removal ◽  
Anaerobic Conditions ◽  
Biochemical Mechanisms ◽  
Biological Phosphorus

Experiments have been performed, using a sequencing batch reactor, to examine the effect of pH on biological phosphorus removal in the activated sludge process. The results, which indicate that glycogen metabolism occurs during anaerobic conditions, are useful in elucidating the biochemical mechanisms involved in phosphorus-removal, and have potential implications for systems such as Phostrip.

Enhanced biological phosphorus removal in the retrofitting from an anoxic selector to an anaerobic selector in a full-scale activated sludge process in Singapore

2009 ◽  
Vol 59 (5) ◽  
pp. 857-865 ◽  
Author(s):  
Y. Cao ◽  
C. M. Ang ◽  
K. C. Chua ◽  
F. W. Woo ◽  
H. Chi ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Phosphorus Removal ◽  
Oxygen Demand ◽  
P Uptake ◽  
Full Scale ◽  
Activated Sludge Process ◽  
Enhanced Biological Phosphorus Removal ◽  
Biological Phosphorus Removal ◽  
Biological Phosphorus ◽  
Final Effluent

This paper presents the investigation results of retrofitting an anoxic selector to an anaerobic selector through stepwise reduction of air supply in a full-scale activated sludge process with a focus on enhanced biological phosphorus removal (EBPR). The process experienced gradual shift from a Ludzack-Ettinger (LE) to an anaerobic-anoxic-oxic (A2O) process and subsequently, an anaerobic-oxic (A/O) process. The major findings are: (i) the average influent-based PO43−-P release in the anaerobic selector compartment was 16.3 mg P l−1 and that in the secondary clarifier was 1.7 mg P l−1. 75% of the SCOD and 93% of the acetic acid in the primary effluent were taken up in the anaerobic selector compartment, respectively; (ii) PO43−-P uptake contributed by both aerobic and denitrifying phosphorus accumulating organisms (DPAOs) occurred mainly in the first and second aerobic lanes together with simultaneous nitrification and denitrification (SND) while there was not much contribution from the last aerobic lane; (iii) The average PO43−-P concentration of the final effluent was 2.4 mg P l−1 corresponding to a removal efficiency of 85%; (iv) the SVI was satisfactory after retrofitting; and (v) the increase of NH4+-N in the final effluent from the commencement to the completion of the retrofitting resulted in an approximate 40–50% reduction in oxygen demand and a significant aeration energy saving was achieved.

Towards exposure of elusive metabolic mixed-culture processes: the application of metaproteomic analyses to activated sludge

2006 ◽  
Vol 54 (1) ◽  
pp. 217-226 ◽  
Author(s):  
P. Wilmes ◽  
P.L. Bond
Keyword(s):  
Protein Expression ◽  
Activated Sludge ◽  
Phosphorus Removal ◽  
Batch Reactor ◽  
Biological Phosphorus Removal ◽  
Microbial Community Structures ◽  
Proteomic Investigation ◽  
Two Phases ◽  
Biological Phosphorus

Protein expression is a direct reflection of specific microbial activities in any ecosystem. In order to assess protein expression in mixed microbial communities, the feasibility of applying proteomic techniques to activated sludge samples has recently been demonstrated. We report the application of metaproteomics to two activated sludges from a laboratory-scale sequencing batch reactor with dissimilar phosphorus removal performances. Fluorescence in situ hybridization (FISH) revealed that the sludge with good enhanced biological phosphorus removal performance (EBPR) was dominated by Betaproteobacteria (65% of EUBMIX binding cells) and gave positive signals for the Rhodocyclus-type PAO specific probe (59%). The non-EBPR sludge was dominated by tetrad-forming Alphaproteobacteria (75%). With regard to the proteomic investigation, 630 individual protein spots were matched across the replicate groups of the anaerobic and aerobic phases of the EBPR sludge with 9.4% of all spots being statistically different between the two phases. The non-EBPR metaproteomic maps exhibited 590 matched spots with 14.7% statistical differences between the two phases. Overall, the non-EBPR sludge expressed around 30% more significant differences than the EBPR sludge. The comparison of protein expression in the two sludges showed that their metaproteomes were substantially different and this was reflected in their microbial community structures and metabolic transformations.

Reduction of coagulant amount added to activated sludge for phosphorus removal

2004 ◽  
Vol 50 (7) ◽  
pp. 287-292 ◽  
Author(s):  
J. Nakajima ◽  
I. Mishima
Keyword(s):  
Activated Sludge ◽  
Phosphorus Removal ◽  
Phosphorus Concentration ◽  
Activated Sludge Process ◽  
Biological Phosphorus Removal ◽  
Fe Content ◽  
The Stability ◽  
And Behavior ◽  
Biological Phosphorus ◽  
Removal Model

Adding coagulant to the activated sludge process is effective in maintaining the stability of phosphorus removal. However, the precise mechanisms of the reaction and behavior of coagulants and phosphorus are not well known. By introducing a new phosphorus removal model (PRM), the behavior of coagulant and phosphorus in the process could be described. The experimental data of the effluent phosphorus concentration and Fe content in the activated sludge agreed with the values calculated by PRM. The amount of coagulant addition to the activated sludge process for phosphorus removal is reduced with the enhanced biological phosphorus removal process. It is suggested that the amount of reduction is determined by using PRM.

scholarly journals The occurrence of enhanced biological phosphorus removal in a 200,000 m3/day partial nitration and Anammox activated sludge process at the Changi water reclamation plant, Singapore

2016 ◽  
Vol 75 (3) ◽  
pp. 741-751 ◽  
Author(s):  
Yeshi Cao ◽  
Bee Hong Kwok ◽  
Mark C. M. van Loosdrecht ◽  
Glen T. Daigger ◽  
Hui Yi Png ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Nitrogen Removal ◽  
Phosphorus Removal ◽  
Ex Situ ◽  
Water Reclamation ◽  
Activated Sludge Process ◽  
Enhanced Biological Phosphorus Removal ◽  
Biological Phosphorus Removal ◽  
Study Results ◽  
Biological Phosphorus

Mainstream partial nitritation and Anammox (PN/A) has been observed and studied in the step-feed activated sludge process at the Changi water reclamation plant (WRP), which is the largest WRP (800,000 m3/d) in Singapore. This paper presents the study results for enhanced biological phosphorus removal (EBPR) co-existing with PN/A in the activated sludge process. Both the in-situ EBPR efficiency and ex-situ activities of phosphorus release and uptake were high. The phosphorus accumulating organisms were dominant, with little presence of glycogen accumulating organisms in the activated sludge. Chemical oxygen demand (COD) mass balance illustrated that the carbon usage for EBPR was the same as that for heterotrophic denitrification, owing to autotrophic PN/A conversions. This much lower carbon demand for nitrogen removal, compared to conventional biological nitrogen removal, made effective EBPR possible. This paper demonstrated for the first time the effective EBPR co-existence with PN/A in the mainstream in a large full-scale activated sludge process, and the feasibility to accommodate EBPR into the mainstream PN/A process. It also shows EBPR can work under warm climates.

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