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.

Stability and variation in sludge properties in two parallel systems for enhanced biological phosphorus removal operated with and without nitrogen removal

1996 ◽  
Vol 34 (1-2) ◽  
pp. 101-109 ◽  
Author(s):  
Natuscka M. Lee ◽  
Hans Carlsson ◽  
Henrik Aspegren ◽  
Thomas Welander ◽  
Bengt Andersson
Keyword(s):  
Activated Sludge ◽  
Nitrogen Removal ◽  
Phosphorus Removal ◽  
Winter Season ◽  
Volume Index ◽  
Enhanced Biological Phosphorus Removal ◽  
Biological Phosphorus Removal ◽  
Conventional System ◽  
Sludge Properties ◽  
Biological Phosphorus

In order to introduce nitrogen removal, many conventional activated sludge systems in Sweden have been transformed into low-loaded systems during the 1990's. Occasionally these systems have been combined with enhanced biological phosphorus removal (EBPR). Increased problems of sludge loss from secondary clarifiers have aroused new interest in the properties of activated sludge. The aim of this study was to investigate the long-term variation and stability of sludge properties in two parallel EBPR systems, operating on the same wastewater. One of the systems was designed as a conventional system, and the other as a low-loaded system with nitrogen removal. The study was performed at the Sjölunda plant in Malmö during a two-year period, in a pilot plant which has been in operation since 1986. The diluted sludge volume index (DSVI) was found to be about 150 ml/g in both systems. The highest values were recorded during the winter season. The variation in the DSVI was much greater in the conventional system than in the low-loaded system. The dominating filamentous bacteria in the conventional system were Type 021N and Thiothrix, and in the low loaded system Type 0041/0675 and Type 0092. The EBPR operation induced large amounts of poly-P-containing flocs in both systems. Although it was not possible to determine to what extent the poly-P-containing flocs affected the sludge properties in this study, it was clearly demonstrated that EBPR operation may not always provide conditions which lead to superior sludge properties.

Population dynamics in wastewater treatment plants with enhanced biological phosphorus removal operated with and without nitrogen removal

2002 ◽  
Vol 46 (1-2) ◽  
pp. 163-170 ◽  
Author(s):  
N. Lee ◽  
J. la Cour Jansen ◽  
H. Aspegren ◽  
M. Henze ◽  
P.H. Nielsen ◽  
...  
Keyword(s):  
Population Dynamics ◽  
Activated Sludge ◽  
Nitrogen Removal ◽  
Phosphorus Removal ◽  
The Other ◽  
Enhanced Biological Phosphorus Removal ◽  
Biological Phosphorus Removal ◽  
Biological Phosphorus ◽  
P Removal

The population dynamics of activated sludge in a pilot plant with two activated sludge systems, both designed for enhanced biological phosphorus removal (EBPR), but one of them with (BNP) and the other without (BP) nitrogen removal, was monitored during a period of 2.5 years. The influent water to the pilot plant was periodically manipulated by external addition of phosphorus (P), acetate and glucose, respectively. The population dynamics and the in situ physiology were monitored by quantitative fluorescence in situ hybridization (FISH) and microautoradiography. Significant P removal was observed in both systems throughout the whole period, with significant increases of the P removal when substrates were dosed. The activated sludge in both systems contained large amounts of dense clusters of gram-negative, methylene-blue staining coccoid rods during the whole period. A large part of the clusters belonged to the β Proteobacteria, whereas the rest of the clusters belonged either to the Actinobacteria or to the α Proteobacteria. The relative abundance of Rhodocyclus-related bacteria in the activated sludge varied significantly in both systems during the whole period (from 6 to 18% in BNP, and from 4 to 28% in BP). However, no statistically significant correlation of the Rhodocyclus-related nor any of the other investigated bacterial groups to the P content of the activated sludge (correlation for all groups investigated was always < 0.5) was observed. A significant 33Pi uptake was observed by the β Proteobacteria (part of them Rhodocyclus-related, the identity of the rest unknown) and the Actinobacteria. However, not all of the Rhodocyclus-related bacteria showed 33Pi uptake. The P removal in the investigated plants is thus believed to be mediated by a mixed population consisting of a part of the Rhodocyclus-related bacteria, the Actinobacteria and other, yet unidentified bacteria.

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.

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