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

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.

1997 ◽  
Vol 35 (1) ◽  
pp. 161-168 ◽  
Author(s):  
A. Carucci ◽  
M. Majone ◽  
R. Ramadori ◽  
S. Rossetti

Experimental work was carried out with a lab-scale SBR, whose operation was divided into three runs: I run (glucose + acetate feed, 3′ fill), II run (only glucose feed, 3′ fill), III run (only glucose feed, 60′ fill). The results show that the bacteria growing in alternating anaerobic/aerobic systems can remove organic substrates under anaerobic conditions even without using the hydrolysis of polyphosphates or the transformation of glycogen into poly-hydroxyalkanoates as the energy sources for the uptake and storage of substrate. However, in the case of acetate plus glucose feed, EBPR can be steadily established with typical PP-bacteria like metabolism even if most of the COD removal takes place under not truly anaerobic conditions.


1997 ◽  
Vol 35 (1) ◽  
pp. 19-26 ◽  
Author(s):  
E. Belia ◽  
P. G. Smith

The development of enhanced biological phosphorus removal (EBPR) through the bioaugmentation of a conventional activated sludge was studied. The objectives of the study were to evaluate the phosphorus removal capability of a sequencing batch reactor (SBR) when started with conventional activated sludge and augmented with a pure culture of Acinetobacter lwoffii. The effect of the addition of the pure culture on the reactor start up time, the settling properties of the sludge and on COD and nitrogen removal was also investigated. The effect of the removal of up to 70% of the bioaugmented biomass and its substitution with unconditioned sludge from a conventional sewage treatment plant was determined. This study has demonstrated that bioaugmentation can convert a conventional sewage works activated sludge to an EBPR sludge in 14 days. The sludge produced shows resilience to influent phosphate fluctuations, low D.O. and biomass replacement. The COD and nitrogen removal capabilities of the sludge and its settling properties are not affected by the addition of the pure culture.


Author(s):  
Shipeng Lu ◽  
Seung Hyun Ryu ◽  
Bok Sil Chung ◽  
Young Ryun Chung ◽  
Woojun Park ◽  
...  

A Gram-negative, motile, rod-shaped bacterium, designated strain EMB325T, was isolated from activated sludge that performed enhanced biological phosphorus removal in a sequencing batch reactor. The predominant fatty acids of strain EMB325T were summed feature 3 (C16 : 1 ω7c and/or iso-C15 : 0 2-OH), C16 : 0, C18 : 1 ω7c and C18 : 1 ω7c 11-methyl. The strain contained phosphatidylethanolamine and diphosphatidylglycerol as polar lipids. The G+C content of the genomic DNA was 63.3 mol%. The major quinone was Q-8. Phylogenetic analysis of 16S rRNA gene sequences showed that strain EMB325T formed a phyletic lineage with members of the genus Simplicispira and was most closely related to Simplicispira psychrophila LMG 5408T and Simplicispira metamorpha DSM 1837T with similarities of 98.1 and 97.9 %, respectively. Levels of DNA–DNA relatedness between strain EMB325T and S. psychrophila LMG 5408T and S. metamorpha DSM 1837T were 28 and 23 %, respectively. On the basis of chemotaxonomic data and molecular characteristics, strain EMB325T is considered to represent a novel species within the genus Simplicispira, for which the name Simplicispira limi sp. nov. is proposed. The type strain is EMB325T (=KCTC 12608T=DSM 17964T).


1994 ◽  
Vol 29 (7) ◽  
pp. 109-117 ◽  
Author(s):  
J. S. Čech ◽  
P. Hartman ◽  
M. Macek

Population dynamics of polyphosphate-accumulating bacteria (PP bacteria) was studied in a laboratory sequencing batch reactor simulating anaerobic-oxic sludge system. The competition between PP bacteria and another microorganism (“G bacteria”) for anaerobic-oxic utilization of acetate as the sole source of organic carbon was observed. The competition was found to be seriously influenced by protozoan and metazoan grazing: Predation-resistant “G bacteria” forming large compact flocs outcompeted PP bacteria. Several breakdowns of enhanced biological phosphorus removal were observed. The first one was related to the development of an euglenid flagellate Entosiphon sulcatus and attached ciliates Vorticella microstoma and V. campanula. The second system collapse was connected with a rapid proliferation of rotifers. An alternative-prey predation was thought to be a mechanism of PP bacteria elimination.


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.


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.


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