Bulking and foaming caused by microthrix parvicella at three large sewage treatment plants in the greater stockholm area

1996 ◽  
Vol 34 (5-6) ◽  
pp. 281-287 ◽  
Author(s):  
Åsa Dillner Westlund ◽  
Eva Hagland ◽  
Maria Rothman
Keyword(s):  
Activated Sludge ◽  
Nitrogen Removal ◽  
Sewage Treatment ◽  
Sewage Treatment Plants ◽  
Microthrix Parvicella ◽  
Relative Scale

Microbiological studies of the activated sludge have been performed continuously at three of the largest sewage treatment plants in Stockholm (Bromma, Henriksdal and Himmerfjärdsverket). All three plants are operated with nitrogen removal. The filamentous organism Microthrix parvicella has been observed at all plants during the study. Large bulking and foaming problems have only been observed at Himmerfjärdsverket although Himmerfjärdsverket is operated at a higher F/M ratio and a lower aerated sludge age than Henriksdal. Bulking has mainly occured at filament abundances above 3 (relative scale 0-6, 0; none, 6; excessive). Large variations in the settleability of the sludge have been observed in the case of sludge collected from different periods but with the same filamentous abundance. The structure of the flocs and the location of the filaments within the flocs have a major impact on the final settleability of the sludge. Foaming in the activated sludge caused by Microthrix parvicella has only been observed at filamentous abundance above 3. During this study, Microthrix parvicella has been observed in the activated sludge when the plant is operated with an aerated sludge age above 3 days and F/M ratios below 0.3 kg BOD7/kg MLSS, day. Operation with a low F/M ratio can be obtained without excessive growth of Microthrix parvicella.

Denitrification in trickling filters

1994 ◽  
Vol 30 (6) ◽  
pp. 181-184 ◽  
Author(s):  
Bernd Dorias ◽  
Peter Baumann
Keyword(s):  
Activated Sludge ◽  
Nitrogen Removal ◽  
Capital Expenditure ◽  
Sewage Treatment ◽  
Innovative Technology ◽  
Activated Sludge Process ◽  
Trickling Filter ◽  
Sewage Treatment Plants ◽  
Trickling Filters ◽  
Test Operation

National and international regulations require a minimum nitrogen removal efficiency of 70% in most public sewage treatment plants. Unlike in activated sludge plants, selective denitrification in trickling filters was not possible until now. Therefore the aim was to employ trickling filter plants for selective denitrification, using innovative technology that involved minimum capital expenditure. For selective denitrification, it is necessary to prevent as much as possible the transfer of oxygen into the trickling filter while feeding the nitrate to be removed, a process similar to upstream denitrification in the activated sludge process. In a test operation conducted in several sewage treatment plants for over a year, the new process with selective denitrification in a covered trickling filter has given successful results. The denitrification efficiency of this system is comparable to that of upstream denitrification in the activated sludge process. Thus, selective denitrification in the trickling filter is a practical alternative to other nitrogen removal processes, while maintaining the established advantages offered by the trickling filter process.

scholarly journals "Candidatus Microthrix parvicella," a Filamentous Bacterium from Activated Sludge Sewage Treatment Plants

1996 ◽  
Vol 46 (1) ◽  
pp. 344-346 ◽  
Author(s):  
L. L. BLACKALL ◽  
H. STRATTON ◽  
D. BRADFORD ◽  
T. DEL DOT ◽  
C. SJORUP ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Sewage Treatment ◽  
Filamentous Bacterium ◽  
Sewage Treatment Plants ◽  
Microthrix Parvicella

Sludge retention time in the secondary clarifier effects on the growth of Microthrix parvicella

1998 ◽  
Vol 37 (4-5) ◽  
pp. 47-50
Author(s):  
Eva Hagland ◽  
Åsa Dillner Westlund ◽  
Maria Rothman
Keyword(s):  
Activated Sludge ◽  
Retention Time ◽  
Sewage Treatment ◽  
Biological Processes ◽  
Bacterial Composition ◽  
Sewage Treatment Plants ◽  
Sludge Retention Time ◽  
Secondary Clarifier ◽  
Microthrix Parvicella ◽  
The Individual

Microbiological examinations have been performed over the last 3 years at 3 large sewage treatment plants in the greater Stockholm area. All 3 plants have periodically suffered from excessive growth of the filamentous bacterium Microthrix parvicella. The growth of Microthrix parvicella was favored by low sludge loading. Results from various plants and from the various parallel systems within the individual plants were compared. The bacterial composition of the activated sludges differed in ways that could not be explained by the sludge loading or the sewage composition. Biological processes in the secondary clarifiers seem to influence the competition between the different organisms in the activated sludge. A clear relationship was shown between high sludge retention time in the secondary clarifiers, VFA production in the return activated sludge (RAS) and a high abundance of Microthrix parvicella.

Examples for the Upgrading of Existing Activated Sludge Plants for Nutrient Removal

1990 ◽  
Vol 22 (7-8) ◽  
pp. 113-121
Author(s):  
W. Maier
Keyword(s):  
Activated Sludge ◽  
Nutrient Removal ◽  
Sewage Treatment ◽  
West Germany ◽  
Sewage Treatment Plants ◽  
Effluent Standards ◽  
Near Future

In view of the new effluent standards in West Germany, including nitrification and phosphorus elimination, many of the existing sewage treatment plants will have to be rebuilt or expanded. Another demand which will have to be dealt with in the near future is denitrification. Under consideration of the large BOD5-loads which were taken into account when designing the plants, many of them nitrify during the summer or can be easily converted to operate with nitrification. Principles for planning the upgrading of such plants have been laid down in order to achieve the required effluent concentrations. The application of these principles is demonstrated with examples of upgraded plants.

Removal Efficiencies of Indicator Micro-Organisms in Sewage Treatment Plants

1989 ◽  
Vol 21 (3) ◽  
pp. 119-124 ◽  
Author(s):  
T. Omura ◽  
M. Onuma ◽  
J. Aizawa ◽  
T. Umita ◽  
T. Yagi
Keyword(s):  
Activated Sludge ◽  
Sewage Treatment ◽  
High Rate ◽  
Coliform Bacteria ◽  
Minor Role ◽  
Activated Sludge Process ◽  
Trickling Filter ◽  
Sewage Treatment Plants ◽  
Micro Organisms ◽  
Chlorine Residuals

The removal of coliform bacteria, enterococcus bacteria, and coliphages in two sewage treatment plants, one using the activated sludge process and the other using a high-rate trickling filter, was investigated over a period of one year. Coliform and enterococcus bacteria were removed with equal efficiency by the two plants, but coliphages were removed more efficiently by the activated sludge process. Experiments on the mechanism of removal revealed that it was mainly due to adsorption on the activated sludge and on the slime in the trickling filter. Die-off of the micro-organisms seemed to play a minor role in the reduction in counts. The treated sewage was disinfected by chlorination prior to discharge into the receiving water. No coliforms were detected in the chlorinated effluents when they had chlorine residuals in the range of 0 to 1.521 mg/l. However, enterococci were detected when chlorine residuals dropped below 0.598 mg/l. Coliphages proved to be the most resistant organisms and they were generally detected throughout the range of chlorine residuals encountered.

Post-Denitrification with Controlled Feeding of Activated Sludge as H Donator

1990 ◽  
Vol 22 (7-8) ◽  
pp. 161-170
Author(s):  
I. Sekoulov ◽  
R. Addicks ◽  
J. Oles
Keyword(s):  
Activated Sludge ◽  
Sewage Treatment ◽  
Domestic Sewage ◽  
Trickling Filter ◽  
Sewage Treatment Plants ◽  
Effluent Quality ◽  
Second Stage ◽  
Denitrification Reactor ◽  
The Given ◽  
Complicated Configuration

Enlargement and/or upgrading of already existing sewage treatment plants will bring problems to design and operation. However, this can be solved even in some complicated configuration of the treatment system, as will be demonstrated. Having an activated sludge system for BOD removal (first stage) followed by a trickling filter for nitrification (second stage), denitrification of the effluent without an external H donator is hard to achieve. In domestic sewage treatment, denitrification is usually carried out with BOD as carbon source. Additionally to the principal question of pre- or post denitrification and the related effects on the effluent quality (BOD, COD, NH4) pre-denitrification in the given case would be highly ineffective and uneconomical (large hydraulic loads). The paper presents a system using thickened sludge from the activated sludge sedimentation as H donator. The sludge has been successfully used to denitrify the trickling filter effluent. For the design of the post-denitrification stage, the necessary volume of sludge could be determined together with the volume of the denitrification reactor. Results of the pilot-plant studies are presented.

Influence of microbial activity on polar xenobiotic degradation in activated sludge systems

2010 ◽  
Vol 62 (3) ◽  
pp. 701-707 ◽  
Author(s):  
M. Majewsky ◽  
T. Gallé ◽  
L. Zwank ◽  
K. Fischer
Keyword(s):  
Activated Sludge ◽  
Microbial Activity ◽  
Suspended Solids ◽  
Sewage Treatment ◽  
Total Suspended Solids ◽  
Active Biomass ◽  
Sewage Treatment Plants ◽  
Degradation Rates ◽  
Xenobiotic Degradation ◽  
Activated Sludge Systems

The influence of activated sludge quality on the co-metabolic biodegradation of three aminopolycarboxyl acids was investigated for a variety of Luxembourg sewage treatment plants. A combination of biodegradation experiments and respirometric techniques are presented as a reliable approach for the estimation of biokinetics and biological xenobiotic degradation rates that allow for identification of governing parameters such as microbial activity and active biomass. Results showed that biokinetics and degradation rates vary greatly between different plants. The fraction of active biomass on the total suspended solids ranged between 16.9 and 53.7%. Xenobiotic biodegradation rates correlated with microbial activity suggesting a relationship with WWTP performance for carbon and nutrient removal. The biokinetic information can be used to increase the prediction accuracy of xenobiotics removal by individual WWTPs.

Sewage-treatment under substantial load variations in winter tourism areas – a full case study

2004 ◽  
Vol 50 (7) ◽  
pp. 147-155 ◽  
Author(s):  
S. Winkler ◽  
N. Natsché ◽  
T. Gamperer ◽  
M. Dum
Keyword(s):  
Activated Sludge ◽  
Nitrogen Removal ◽  
Nutrient Removal ◽  
Sewage Treatment ◽  
Activated Sludge Process ◽  
Two Stage ◽  
Winter Tourism ◽  
Load Variations ◽  
Sudden Load

The sewage-load variations in winter tourism areas are characterized by sudden increases - in the ange of a factor two to three - within only a few days at the start and the end of the tourist season, especially at Christmas. The sudden load increases occur during periods of low wastewater temperatures, which is an additional demanding factor with respect to nitrogen removal. A full case study was carried out at WWTP Saalfelden, which is located near one of Austria's largest skiing resorts. The plant is designed for 80,000 PE and built according to the HYBRID®-concept, which is a special two stage activated sludge process for extensive nutrient removal.

Tentative Nitrogen Removal with Fixed Bed Processes in Malmö Sewage Treatment Plant

1990 ◽  
Vol 22 (1-2) ◽  
pp. 239-250 ◽  
Author(s):  
B. Andersson
Keyword(s):  
Activated Sludge ◽  
Nitrogen Removal ◽  
Sewage Treatment ◽  
Fixed Bed ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Full Scale ◽  
Trickling Filter ◽  
Test Program ◽  
Made In

A test program for the use of fixed bed processes in systems for nitrogen removal at an advanced sewage treatment plant is described. Results from studies on nitrification in a full scale trickling filter plant with different filter depths and at different wastewater temperatures are presented. Results from full scale experiments with denitrification/nitrification in a retrofitted activated sludge plant are also presented. The effect of an aerated submerged fixed bed in the aeration basin on nitrification was investigated. Observations of the biofilm formed on the fixed bed were made in microscope.

Sign in / Sign up

Export Citation Format

Share Document