Evaluation of the Efficiency of a New Aeration System at Henriksdal Sewage Treatment Plant

1988 ◽  
Vol 20 (4-5) ◽  
pp. 85-92 ◽  
Author(s):  
L.-G. Reinius ◽  
J. Hultgren
Keyword(s):  
Air Flow ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Design Flow ◽  
The Other ◽  
Aeration Tank ◽  
Aeration System ◽  
Term Change ◽  
Fine Bubble

Henriksdal sewage treatment plant is the largest plant in Stockholm with a design flow of 370 000 m3/d. In one aeration tank of eleven a new fine-bubble aeration system has been in operation since August 1985. The tank is divided into 6 equal parts. The first part is an anoxic zone and the other five are aeration zones with tapered diffusers. Several instruments are installed in the block including separate air flow monitors in each of the five zones and D.O.-probes in the inlet and outlet of the zones. Equipment for flow measurement of settled sewage and return sludge is also installed. Every instrument is connected to a computer for data acquisition. To evaluate the efficiency of the aeration system the oxygenation transfer capacity has been calculated from the oxygen massbalance equation for each zone as a function of air flow. To solve this equation the respiration has to be known and this is done by a simple respirometer for samples of the MLSS in each zone. When the KLa-values are known as functions of the air flow the mass balance equation can be used to calculate the respiration rate in each zone. The computer has been logging data for 2 2 months, and it is possible to calculate the respiration rates in the different zones every hour during this period. It is very important to know the respiration along the tank and how it varies to get the optimal tapering of the diffusers when it is time to change the aeration system in the other 10 tanks. The calculations show a different pattern in the respiration over the year depending on the rate of nitrification. Another use of the calculation of the oxygenation transfer efficiency is to recognize if any long-term change occurs due to clogging of the diffusers.

Causes of observed temporal variability of nutrient fluxes from a southern Australian marine embayment

1999 ◽  
Vol 50 (6) ◽  
pp. 581 ◽  
Author(s):  
Geoff J. Nicholson ◽  
Andy R. Longmore
Keyword(s):  
Water Temperature ◽  
Water Column ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
The Other ◽  
Total Carbon ◽  
Phosphate Silicate ◽  
Benthic Chambers ◽  
Marine Embayment

Benthic chambers were used to measure temporal differences of sediment–water column flux of dissolved oxygen (DO), ammonium, nitrite plus nitrate, phosphate, silicate and total carbon dioxide (TCO2) in Port Phillip Bay. Three clear and three dark benthic chambers were deployed between October 1994 and January 1996 at each of three sites: near the outflow of a major sewage treatment plant, near the mouth of a river and in the deep centre of the bay. Analysis of variance indicated that chamber type did not significantly affect magnitude of flux for the majority of deployments. Water temperature at the time of deployment had a significant effect on the fluxes of DO, TCO2 , NH4 , and SiO4 at the central bay site and for all fluxes at the other two sites. There was a relationship between TCO2 flux in the sediment and C production in the water column (r2 = 0.6552). The denitrification efficiency at the central bay site was usually >80% at all times, and altered by ~30% seasonally at the other two sites. It is likely that the effect of water temperature on a suite of biological processes is the predominant source of temporal variation in these benthic fluxes.

The Infuence of the Depth of the Secondary Sedimentation Tanks on the Sedimentation Efficiency at Bromma Sewage Treatment Plant

1988 ◽  
Vol 20 (4-5) ◽  
pp. 143-152 ◽  
Author(s):  
M. Tendaj-Xavier ◽  
J. Hultgren
Keyword(s):  
Activated Sludge ◽  
Suspended Solids ◽  
Ferrous Sulphate ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Design Flow ◽  
Activated Sludge Process ◽  
Solids Concentration ◽  
Rapid Flow

Bromma sewage treatment plant is the second largest plant in Stockholm with a design flow of 160,000 m3/d. The wastewater is treated mechanically, chemically by pre-precipitation with ferrous sulphate, and biologically by the activated sludge process. The requirements for the plant are 8 mg BOD7/l, 0.4 mg P/l and 2 mg NH4+-N/l. The requirement for ammonia refers to the period July-October. In order to meet those rather stringent requirements, the biological step was expanded 3 years ago with 6 new sedimentation tanks. The 6 new tanks have the same area as the 6 old ones but they have only a depth of 3.7 m compared with the depth of the old tanks, 5.7 m. Experience from the first years of operation of the new tanks is that these tanks are more sensitive and less efficient than the older ones. It seems that the effluent suspended solids concentration from the old tanks is less influenced by rapid flow variations than the concentration in the effluent from the new secondary sedimentation tanks. During the nitrification period denitrification takes place to some degree in the secondary sedimentation tanks. This may cause loss of solids and it has been observed that the deeper old tanks usually produce an effluent of better quality and seem to be less influenced by denitrification than the new ones.

Upgrading of the Treatment Plants in Stockholm to Meet More Stringent Requirements

1990 ◽  
Vol 22 (7-8) ◽  
pp. 77-84
Author(s):  
J. Hultgren ◽  
L.-G. Reinius ◽  
M. Tendaj
Keyword(s):  
Nitrogen Removal ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Design Flow ◽  
Limit Values ◽  
Mean Values ◽  
Reject Water ◽  
Low Phosphorus ◽  
Anoxic Zones

The purification requirements for the Stockholm sewage treatment plants will become more stringent in the future. The expected limit values for the effluent, expressed as annual mean values, are for BOD7, Tot-P, and Tot-N, 10, 0.3 and 15 mg/l respectively. If these contents are multiplied by the design flow values for the three plants, we obtain the maximum quantities which may be released. If the relevant authorities permit the municipality to distribute these total quantities as desired between the three plants, future necessary extensions can be optimized. The following main principles apply to an extension of the three plants: Loudden sewage treatment plant: This comparatively small treatment plant could, if the requirements are lower than in the other two plants, continue in operation with no other extensions than the inclusion of anoxic zones. It would, however, be necessary to refurbish the plant after a number of years of neglected maintenance. Bromma sewage treatment plant: The biological stage was extended during the 1982-84 period. For this reason, the municipality suggests that no further extensions of the aeration tanks be required, before 1995 at the earliest. A nitrogen removal with outgoing contents of Tot-N of 15-17 mg/l is expected to be achieved by measures taken to reduce the load on the biological stage instead. These measures consist of centrifuging the excess sludge and pumping it directly to the digesters instead of returning it to the inlet. Furthermore, separate treatment of the reject water from the sludge centrifuges is planned. A third measure could be changing over to a more efficient precipitation chemical to permit a further reduction of the load on the biological stage with regard to, inter alia, BOD7, Tot-N etc. To meet the requirements for phosphorus removal (0.3 mg/l), the plant will be extended with a filter stage after the existing biological stage. Henriksdal sewage treatment plant: At this plant, which is the largest of the three, the largest extensions are planned. To meet the requirements for nitrogen removal, the present volumes in the aeration tanks will be tripled and will be utilized as anoxic and aerated zones as required. Three new lines with aeration tanks and secondary sedimentation tanks will be constructed. The existing aeration tanks will also be deepened from 5 to 12 m. The requirements for low phosphorus contents in the effluent will be met by installing a filter stage, as in the Bromma plant.

Changes in Microfauna at the Time of Occurrence and Disappearance of Filamentous Bulking

1991 ◽  
Vol 23 (4-6) ◽  
pp. 907-916 ◽  
Author(s):  
M. Terashi ◽  
S. Hamada
Keyword(s):  
Hydrogen Sulfide ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Aeration Tank ◽  
Activated Sludge Process ◽  
Filamentous Bacteria ◽  
Filamentous Bulking ◽  
Final Effluent ◽  
Low Do

In the activated sludge process, the cause of filamentous bulking is often the filamentous bacteria Type 021N. At the Kitaminato sewage treatment plant, it was found that when the DO in the aeration tank decreased, filamentous bulking occurred. If the low DO condition is allowed to continue, anaerobic degraded organic matter is produced which creates a favorable condition for the multiplication of Type 021N. Entosiphon sp. is reported to show resistance to low DO; however, sometimes before filamentous bulking occurs, Entosiphon sp. itself multiples. Also if Entosiphon sp. increases and Cinetochilummargaritaceum, of the Ciliophora, multiples, then bulking by Type 021N has been seen not to occur. Cinetochilummargaritaceum has low resistance to hydrogen sulfide; therefore, hydrogen sulfide must not be present in the aeration tank and this means that bulking by Type 021N can not become serious. However, if filamentous bulking becomes serious, only increasing the DO level in the aeration tank will not cause the disappearance of the filamentous bulking. At this stage, if we allow 30% of the final effluent to flow back into the grit chamber, then Type 021N decreases. This is because Trithigmostomacucullulus, of the Ciliophora, increases to 3,000 number/ml, and it ingests Type 021N.

Evaluation of total emissions from treatment plants and combined sewer overflows

1998 ◽  
Vol 37 (1) ◽  
pp. 333-340 ◽  
Author(s):  
Joachim Guderian ◽  
Andreas Durchschlag ◽  
Jürgen Bever
Keyword(s):  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Design Flow ◽  
Simulation Tool ◽  
Combined Sewer Overflows ◽  
Flow Management ◽  
Sewer Systems ◽  
Optimal Value ◽  
Combined Sewer

Based upon the connection of a simulation program for combined sewer systems with the IAWQ-Activated Sludge Model No.1 the new simulation tool GEMINI was developed, which allows the calculation of sewer and sewage treatment plant as a unit. Some obtained results are presented in an example. They suggest, that for every treatment plant a rate of inflow is determinable, which leads to a minimum of total emissions out of sewer and treatment plant. The optimal value of sewage treatment plant inflow in the example is distinctly greater than the design flow rate fixed in German design rules. So it is recognizable that a rigid flow management for sewer and treatment plant does not always fulfil the aim of minimization of total emissions.

Isolation and Identification of Nitrobacteria Adapted to Low Temperature

2012 ◽  
Vol 518-523 ◽  
pp. 406-410 ◽  
Author(s):  
Yun Hao ◽  
Xiu Guang Jiang ◽  
Qing Tian ◽  
Ai Yin Chen ◽  
Bao Ling Ma
Keyword(s):  
Low Temperature ◽  
Removal Efficiency ◽  
Nitrate Removal ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Ammonia Nitrogen ◽  
Aeration Tank ◽  
Isolation And Identification ◽  
Nitrification Process

In this study, a scientific method which can be used to improve nitrification process at low temperature in the sewage treatment plant was introduced. The activated sludge samples were taken from aeration tank of the sewage treatment plant when the outside temperature was below 0°C (water temperature below 12 °C). Five kinds of nitrobacteria strains with cold-resistance and higher activity of ammonia degradation were isolated from aeration tanks. The physiological properties showed the five strains were identified into Sphingobacteriaceae、Rhodanobacter sp.、Pseudomonas sp.、Pandoraea sp. and Perlucidibaca piscinae. All of the strains could convert ammonia-nitrogen or NO2- into NO3- in the medium at 10°C. The ammonia and nitrate removal efficiency could be reached 80.9% and 80.3% respectively. Comparing to the unvaccinated one, the removal efficiency can be increased by 50%, which proved the isolated nitrobacteria could be applied to biological nitrification process of sewage treatment at low-temperature.

Screening and Degradation Characteristics of Anthracene-Degrading Strains

2012 ◽  
Vol 610-613 ◽  
pp. 52-55
Author(s):  
Shan Shan Liu ◽  
Xiao Yan Liu ◽  
Xia Liang ◽  
Fa Hui Liu ◽  
Jun Chen Zou ◽  
...  
Keyword(s):  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Growth Conditions ◽  
The Other ◽  
Bacterial Strains ◽  
Rdna Genes ◽  
Degradation Rates ◽  
Pseudomonas Nitroreducens ◽  
Optimum Growth Condition

Two efficient anthracene-degrading strains are isolated from pollution sludge collected from sewage treatment plant and identified by sequencing their 16S rDNA genes, one is Pseudomonas nitroreducens and the other is Bacillus sp.. The proper growth conditions of each bacterium was measured and presented for anthracene-degrading. The optimum growth condition is pH 7.5, 30°C. Biodegradation assays revealed that the degradation rates of two bacterial strains are 82.3% and 80.7% in 7 days. Respectively, the two bacteria had played important roles in the degradation of anthracene.

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