Survey of filamentous populations in nutrient removal plants in four European countries

1998 ◽  
Vol 37 (4-5) ◽  
pp. 281-289 ◽  
Author(s):  
Dick H. Eikelboom ◽  
Andreas Andreadakis ◽  
Kjaer Andreasen
Keyword(s):  
Nutrient Removal ◽  
Seasonal Pattern ◽  
Plug Flow ◽  
Phosphate Removal ◽  
Particulate Fraction ◽  
Biological Nutrient Removal ◽  
Process Conditions ◽  
Minor Importance ◽  
Filamentous Microorganisms ◽  
Short Period

A joint EU research project aimed at solving activated sludge bulking in nutrient removal plants was initiated in 1993. The project started with a survey of the size and composition of the filamentous population in nutrient removal plants in Denmark, Germany, Greece and the Netherlands. The results show that biological nutrient removal process conditions indeed favour filamentous microorganisms in their competition with floc forming organisms. An increase in the size of the filamentous population resulted in a deterioration of the settling properties of the biomass, except for plants with Bio-P removal conditions. It is assumed that in the latter case the dense clusters of Bio-P bacteria increase the weight of the flocs, and compensate for the effect of the larger number of filaments. Although exceptions frequently occur, the following sequence in decreasing filamentous organism population size was observed for the process conditions indicated: - completely mixed + simultaneous denitrification; - completely mixed + intermittent aeration/denitrification; - alternating anoxic/oxic process conditions, with an anaerobic tank for biological phosphate removal (Bio-Denipho); - alternating anoxic/oxic process conditions (Bio-Denitro); - predenitrification The surveys provided little information about the effect of nutrient removal in plants with plug flow aeration basins. Simultaneous precipitation with aluminium salts nearly always resulted in a low number of filaments and a good settling sludge. The size of the filamentous organism population showed a seasonal pattern with a maximum in winter/early spring and a minimum during summer (in Greece: during autumn). This seasonal variation is primarily caused by the effect of the season on the population sizes of M. parvicella, N. limicola and Type 0092. M. parvicella is by far the most important filamentous species in nutrient removal plants. In Denmark only, Type 0041 also frequently dominates the filamentous population, but seldom causes severe bulking. Considering their frequency of occurrence, approx. 10 other filamentous micro-organisms are of minor importance. Growth of some of these species, viz. those which use soluble substrate, can be prevented by the introduction of Bio-P process conditions. M. parvicella and Type 0041 (and probably also Actinomycetes and the Types 1851 and 0092) seem to compete for the same substrates i.e. the influent particulate fraction. Most of the differences in composition of the filamentous microorganism population can be explained by whether or not premixing of influent and recycled sludge is used. In general, premixing for a short period of time followed by anoxic conditions favours Type 0041. M. parvicella seems to proliferate if the particulate fraction is first hydrolysed or if it enters the plant via an oxic zone. It is concluded that bulking in nutrient removal plants is mainly caused by filamentous species requiring the particulate fraction for their growth.

Settling Characteristics of Activated Sludge in Danish Treatment Plants with Biological Nutrient Removal

1994 ◽  
Vol 29 (7) ◽  
pp. 157-165 ◽  
Author(s):  
Gert Holm Kristensen ◽  
Per Elberg Jørgensen ◽  
Per Halkjær Nielsen
Keyword(s):  
Activated Sludge ◽  
Nutrient Removal ◽  
Volume Index ◽  
Biological Nutrient Removal ◽  
Sludge Volume Index ◽  
Filamentous Microorganisms ◽  
Best Parameter ◽  
One Year ◽  
Sludge Settling ◽  
Settling Characteristics

In 1989-91, a study was performed to investigate the settling characteristics of activated sludge in Danish treatment plants with biological nutrient removal. The study included three screening series on 38 treatment plants. Furthermore, the study included investigations during one year on seasonal variations in sludge settling characteristics at three treatment plants. The screening investigations were performed in November 1989 and May and September, 1990. Results showed that in the May-screening, 35-45% of the plants had a filament index of 2-2.5 or above, corresponding to a sludge volume index above 150 ml/g. When comparing data for diluted and non-diluted sludge volume indices, a SVI value of 150 ml/g seemed parallel to a DSVI of 110 ml/g. In the November- and September-screenings, some 30% of the plants had activated sludge showing a filament index in or above the critical area. Dominating filamentous microorganisms were found to be (in decreasing order): Microthrix parvicella, Type 0041, Type 021N, Type 0092, Type 0914, and Type 1851. A distinct variation over the year in sludge settling characteristics was found for the three plants. Sludge settling characteristics improved during summer, and deteriorated during winter. For activated sludge with a high content of filamentous microorganisms, the best parameter to follow the variations in sludge settling properties was the filament number. If the activated sludge concentration, the MLSS, varied significantly, the specific filament number was to be applied.

The effect of chemical bulking control on biological nutrient removal in a full scale activated sludge plant

1996 ◽  
Vol 34 (3-4) ◽  
pp. 275-282 ◽  
Author(s):  
G. B. Saayman ◽  
C. F. Schutte ◽  
J. van Leeuwen
Keyword(s):  
Hydrogen Peroxide ◽  
Activated Sludge ◽  
Nutrient Removal ◽  
Pilot Scale ◽  
Full Scale ◽  
City Council ◽  
Phosphate Removal ◽  
Biological Nutrient Removal ◽  
Removal Processes ◽  
The City

The use of chemicals for sludge bulking control has a direct effect on the biological nutrient removal processes in activated sludge systems designed for this purpose. Chlorine has been used on full scale but information on the use of ozone and hydrogen peroxide is limited to pilot scale tests. The objective of this study was to investigate the effects of chlorine, ozone and hydrogen peroxide on nutrient removal processes when used on a continuous basis for bulking control in a full scale biological nutrient removal activated sludge plant. The full scale studies were conducted over a period of 39 months at the Daspoort sewage works of the City Council of Pretoria. The results indicate that at low dosages the oxidants have limited effects on the nutrient removal processes but at higher levels chlorine had a detrimental effect resulting in the phosphate limit of 1 mg P.1−1 being exceeded. It is concluded that chlorine is the most effective of the three oxidants for bulking control, but that it should be used with caution in order not to upset the biological phosphate removal processes. Ozone at low levels had a small but consistent positive effect on bulking control as well as on nutrient removal. The effects of hydrogen peroxide were very small except at high dosages.

A novel nearly plug-flow membrane bioreactor for enhanced biological nutrient removal

AIChE Journal ◽  
2012 ◽  
Vol 59 (1) ◽  
pp. 46-54 ◽  
Author(s):  
Fangang Meng ◽  
Zhongbo Zhou ◽  
Lei Li ◽  
Ruiyun Li ◽  
Xiaoshan Jia ◽  
...  
Keyword(s):  
Nutrient Removal ◽  
Membrane Bioreactor ◽  
Plug Flow ◽  
Biological Nutrient Removal

Microbial evaluation of activated sludge and filamentous population at eight Czech nutrient removal activated sludge plants during year 2000

2002 ◽  
Vol 46 (1-2) ◽  
pp. 471-478 ◽  
Author(s):  
O. Krhutková ◽  
I. Ruzicková ◽  
J. Wanner
Keyword(s):  
Activated Sludge ◽  
Nutrient Removal ◽  
Microbial Population ◽  
Point Of View ◽  
Biological Nutrient Removal ◽  
Filamentous Microorganisms ◽  
Microthrix Parvicella ◽  
Year 2000 ◽  
The Relationship

The long-term project on the survey of filamentous microorganisms, which started in 1996, was finished in 2000 by the survey of eight Czech activated sludge plants with biological nutrient removal (BNR) systems. At all plants with enhanced biological nutrient removal, specific microbial population (mostly from the point of view of filaments occurrence), operational problems (presence of biological foaming, bulking) and plant operation were observed periodically and longer than 1 year. In our paper the relationship between the composition of activated sludge (especially filaments) consortia and modification of the process with nutrient removal is discussed. At the surveyed plants Type 0092 and Microthrix parvicella were identified as dominant Eikelboom filamentous types.

Bulking sludge solved?!

2002 ◽  
Vol 46 (1-2) ◽  
pp. 457-464 ◽  
Author(s):  
J. Kruit ◽  
J. Hulsbeek ◽  
A. Visser
Keyword(s):  
Nutrient Removal ◽  
Wastewater Treatment Plants ◽  
Plug Flow ◽  
Biological Nutrient Removal ◽  
Ammonium Concentration ◽  
Strictly Anaerobic ◽  
Flow Conditions ◽  
Anaerobic Reactor ◽  
Aerobic Reactor ◽  
Sludge Settling

At present there is still no final theory explaining the bulking of activated sludge. Previous investigations showed that the sludge settling properties become better and more stable when more plug flow conditions are implemented in wastewater treatment plants for biological nutrient removal. In this research the effect of the process configuration (4 wwtps with fully biological nutrient removal) on the sludge settling properties has been investigated. The results show that a separate anoxic reactor can not avoid the presence of LCFA for the growth of M. parvicella in the anaerobic reactor. A SVI < 120 ml/g could be achieved by: implementation of a separate anoxic reactor with plug flow conditions, introducing of a strictly anaerobic reactor (UCT-modification), implementation of an extra anoxic/aerobic reactor, maintaining a high oxygen concentration (> 1.5 mg/l) and creating a low ammonium concentration (< 1 mg/l) in the aerobic reactor.

16S rRNA in situ probing for the determination of the family level community structure implicated in enhanced biological nutrient removal

2001 ◽  
Vol 43 (1) ◽  
pp. 91-98 ◽  
Author(s):  
D. D. Mudaly ◽  
B. W. Atkinson ◽  
F. Bux
Keyword(s):  
Activated Sludge ◽  
Nutrient Removal ◽  
Phosphate Removal ◽  
Microbial Community Analysis ◽  
Biological Nutrient Removal ◽  
Total Bacterial Count ◽  
Family Level ◽  
Acinetobacter Spp ◽  
Alpha Proteobacteria

Knowledge of a discrete physiological group capable of excess biological phosphate removal (EBPR) remains unclear. Consequently, microbial community analysis of an enhanced continuous laboratory-scale activated sludge process displaying a strong EBPR mechanism was conducted. Unit design was configured upon the three-stage Phoredox process and characterization of the activated sludge bacterial community was carried out using fluorescent in situ hybridization (FISH) techniques. Fixed activated sludge samples were hybridized with fluorescently labeled oligonucleotide probes targeting the following bacterial phylogenetic divisions: a kingdom level probe specific for all bacteria (EUB338); family level probes specific for the alpha, beta and gamma subclasses of the class Proteobacteria; Gram positive bacteria with a high (G+C) DNA content (GPBHGC) or Actinobacteria; the Cytophaga-Flavobacterium (CF) subclass within the Cytophaga-Flavobacterium-Bacteriodes division; and genus level probes specific for Pseudomonas spp., Aeromonas spp., and Acinetobacter spp. Bacterial predominance between the anaerobic, anoxic and aerobic zones of the EBPR sludge were comparable and appeared as follows; beta (22%), alpha (19%), gamma (17%), GPBHGC (11%) and CF (8%). The incidence of Acinetobacter spp. appeared to be generally low with counts amounting to <9% of the total bacterial count. A population shift in the alpha Proteobacteria subclass was evident between the non-nutrient removal seed sludge and the EBPR sludge, implicating this group in EBPR. The overall results indicate that the beta and alpha Proteobacteria can be metabolically functional in EBPR processes and reiterate the functional misconception of Acinetobacter spp. in EBPR systems.

Performance and model calibration of R-D-N processes in pilot plant

1994 ◽  
Vol 30 (6) ◽  
pp. 355-364 ◽  
Author(s):  
A. de la Sota ◽  
L. Larrea ◽  
L. Novak ◽  
P. Grau ◽  
M. Henze
Keyword(s):  
Nutrient Removal ◽  
Pilot Plant ◽  
Model Calibration ◽  
Domestic Wastewater ◽  
Biological Nutrient Removal ◽  
Quasi Steady State ◽  
Batch Tests ◽  
Filamentous Microorganisms ◽  
Inhibition Of Nitrification ◽  
Removal Processes

This paper deals with the first part of an experimental programme in a pilot plant configured for advanced biological nutrient removal processes treating domestic wastewater of Bilbao. The IAWPRC Model No. 1 was calibrated in order to optimize the design of the full-scale plant. In this first phase the R-D-N process, incorporating an anoxic selector, was tested for eight months at three temperatures of approximately 20°C, 15°C and 11°C. Under quasi-steady state conditions the ammonia effluent varied from 1 to 5 mg N/l. A partial inhibition of nitrification in some periods was detected. This was clearly shown by regular maximum AUR batch tests and by the model calibration. The influent COD/TKN ratio was rather low (8-9) and the effluent nitrate concentrations varied from 10 to 12 mg N/l. The DSVI increased from 50 to 115 ml/g as the temperature decreased from 20°C to 11°C. An appropriate balance between floc-forming and filamentous microorganisms was maintained as a consequence of the combined configuration of the anoxic selector and the regeneration zone.

The invisible BNR plant provides high quality effluent and recreational area for densely populated urban area

2009 ◽  
Vol 4 (1) ◽  
Author(s):  
E. Choi ◽  
Z. Yun ◽  
K.S. Min
Keyword(s):  
Nutrient Removal ◽  
Operating Temperature ◽  
Treatment Plant ◽  
Ground Level ◽  
Biological Nutrient Removal ◽  
High Quality ◽  
Sand Filter ◽  
Sport Facilities ◽  
Final Effluent ◽  
Removal System

In a densely populated area, a large wastewater treatment plant (WWTP) has been constructed in the underground. The plant is practically “invisible” to visitors and neighbours, and the ground level is used as a park and sport facilities in order to avoid the “not in my backyard” phenomenon. The WWTP has a 5-stage biological nutrient removal system utilizing the denitrifying PAO (dPAO) with a step feed in order to treat the weak sewage with higher nutrient removal requirement. Although the underground installation could be expected to increase plant operating temperature, the temperature increase was only 1°C. The polished final effluent from a sand filter produced average TN and TP concentrations of 5.11 mg/L and 0.91 mg/L, respectively with SS concentrations of 0.61 mg/L, indicating that the dPAO system combined with sand filter effectively produced a high quality effluent.

Upgrading Wastewater Treatment Plants for Biological Nutrient Removal

1990 ◽  
Vol 22 (7-8) ◽  
pp. 53-60 ◽  
Author(s):  
B. Rabinowitz ◽  
T. D. Vassos ◽  
R. N. Dawson ◽  
W. K. Oldham
Keyword(s):  
Wastewater Treatment ◽  
Nutrient Removal ◽  
Wastewater Treatment Plants ◽  
Design Flow ◽  
Biological Nutrient Removal ◽  
Nitrogen And Phosphorus ◽  
Conventional Activated Sludge ◽  
Recent Developments ◽  
Removal Technology ◽  
Biological Nitrogen

A brief review of recent developments in biological nitrogen and phosphorus removal technology is presented. Guidelines are outlined of how current understanding of these two removal mechanisms can be applied in the upgrading of existing wastewater treatment plants for biological nutrient removal. A case history dealing with the upgrading of the conventional activated sludge process located at Penticton, British Columbia, to a biological nutrient removal facility with a design flow of 18,200 m3/day (4.0 IMGD) is presented as a design example. Process components requiring major modification were the headworks, bioreactors and sludge handling facilities.

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