An assessment of excess biological phosphorus removal during activated sludge treatment

1988 ◽  
Vol 9 (7) ◽  
pp. 637-646 ◽  
Author(s):  
S. Yeoman ◽  
M. Hunter ◽  
T. Stephenson ◽  
J.N. Lester ◽  
R. Perry
1985 ◽  
Vol 17 (11-12) ◽  
pp. 309-310 ◽  
Author(s):  
W. Maier ◽  
P. Kainrath ◽  
Kh Krauth ◽  
R. Wagner

Enhanced biological phosphorus removal from domestic sewage was investigated in a single-stage activated sludge treatment plant with pre-denitrification operated in a continuous process. In 10 different experimental periods the influence of varying composition of the influent, varying systems of the pilot scale unit (with and without anaerobic basin), varying retention times in the different basins and varying sludge loads were investigated. Results of the experiments can be summarized as follows: the nutrient situation and especially the P/BOD5 and N/BOD5 ratios, retention time in the final clarifier, and organic sludge load plus the desired degree of nitrification have essential influence on the process and P removal efficiency. The conclusions for the pilot scale process are discussed.


1999 ◽  
Vol 39 (6) ◽  
pp. 37-43 ◽  
Author(s):  
Damir Brdjanovic ◽  
Mark C. M. van Loosdrecht ◽  
Christine M. Hooijmans ◽  
Takashi Mino ◽  
Guy J. Alaerts ◽  
...  

This paper describes several techniques and methods for sludge characterization which are recently developed and used in our ongoing research on biological phosphorus removal (BPR): (i) chemical measurement of the poly-hydroxy-alkanoate (PHA) content of the biomass, (ii) bioassay for glycogen determination in BPR systems, (iii) determination of the fraction of denitrifying phosphorus accumulating organisms (DPAOs) in P-removing sludge, (iv) determination of the aerobic and anoxic ATP/NADH2 ratio (δ value) in BPR systems, and (v) determination of the glycogen accumulating organisms (GAOs) / phosphorus accumulating organisms (PAOs) ratio in activated sludge.


1982 ◽  
Vol 14 (1-2) ◽  
pp. 31-45 ◽  
Author(s):  
J L Barnard

This paper discusses the need for anaerobiases as a pre-requisite for phosphorus removal in activated sludge plants and the effect of nitrates on the anaerobic conditions. If the plant could be operated to avoid nitrification, biological phosphorus removal presents no problems. When nitrification is required, the nitrates must be reduced to a low level through internal denitrification. If sufficient carbon is available to ensure complete removal of the nitrates and anaerobic conditions in a specific zone in the plant, good phosphate removal can be ensured. Below COD : TKN ratios of 10 : 1 it is becoming more difficult to control the plant and special care should be taken to determine not only the quantity of organic carbon available as electron donors for removal of the nitrates but also the form in which it arrives at the plant.


1985 ◽  
Vol 17 (11-12) ◽  
pp. 23-41 ◽  
Author(s):  
M. C. Hascoet ◽  
M. Florentz ◽  
P. Granger

Enhanced biological phosphorus removal from wastewater by means of microorganisms found in activated sludge has for the past few years been the subject of much research and it is now commonly recognized that an activated sludge system must include alternating anaerobic-aerobic periods. The present article covers biochemical aspects of this phenomenon using a phosphorus removing biomass obtained in a laboratory-scale pilot with alternating phases and a synthetic substrate feed. The percentage of phosphorus obtained in the pilot sludge was four times greater than that of a conventional sludge plant. By exposing the same biomass to different conditions and using 31P Nuclear Magnetic Resonance, we were able to accurately pin-point the various forms of phosphorus found within cells and follow their development during the course of alternating phases. The following results were obtained:the transformation of phosphorus in its inorganic to polyphosphate form depends on the medium's level of oxygenation,the presence of nitrates disturbs the anaerobic period but does not affect phosphorus uptake in the aerated period.Continuous nitrate addition alters biomass behaviour in the anaerobic phase, which loses the capacity to release phosphorus,copper at a concentration of over 1 mg Cu2+/1 inhibits phosphorus uptake in the aerated phase. Various microbiological analyses made on the pilot biomass isolated conventional bacteria found in activated sludge.


2019 ◽  
Vol 79 (8) ◽  
pp. 1467-1473 ◽  
Author(s):  
Knut Rudi ◽  
Inger Andrea Goa ◽  
Torgeir Saltnes ◽  
Gjermund Sørensen ◽  
Inga Leena Angell ◽  
...  

Abstract Phosphorus is both a major environmental pollutant and a limiting resource. Although enhanced biological phosphorus removal (EBPR) is used worldwide for phosphorus removal, the standard activated sludge-based EBPR process shows limitations with stability and efficiency. Recently, a new EBPR moving bed biofilm reactor (MBBR) process has been developed at HIAS (Hamar, Norway), enabling a phosphorus removal stability above 90% during a whole year cycle. To increase the knowledge of the HIAS (MBBR) process the aim of the current work was to characterize the MBBR microbiota and operational performance weekly for the operational year. Surprisingly, we found a major succession of the microbiota, with a five-fold increase in phosphorus accumulating organisms (PAOs), and major shifts in eukaryote composition, despite a stable phosphorus removal. Temperature was the only factor that significantly affected both phosphorus removal and the microbiota. There was a lower phosphor removal during the winter, coinciding with a higher microbiota alpha diversity, and a lower beta diversity. This differs from what is observed for activated sludge based EBPR. Taken together, the knowledge gained from the current microbiota study supports the efficiency and stability of MBBR-based systems, and that knowledge from activated sludge-based EBPR approaches cannot be translated to MBBR systems.


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