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.

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.

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.

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.

Operation Experiences with Biological Phosphorus Removal at the Sewage Treatment Plants of Berlin (West)

1991 ◽  
Vol 24 (7) ◽  
pp. 133-148 ◽  
Author(s):  
A. Peter ◽  
F. Sarfert
Keyword(s):  
Phosphorus Removal ◽  
Sewage Treatment ◽  
Chemical Precipitation ◽  
Biological Phosphorus Removal ◽  
Treatment Results ◽  
Sewage Treatment Plants ◽  
Research Activities ◽  
Two Stages ◽  
The Given ◽  
Biological Phosphorus

In investigations concerning sludge bulking in Berlin enhanced biological phosphorus removal was first observed unexpectedly. Because since 1986 an officially preset limit of 2 mg TP/l must be kept in all Berlin wastewater discharges it was decided to explore the capabilities of the observed mechanism under the specific circumstances of the exciting two large treatment plants in Ruhleben (240,000 m3/d) and Marienfelde (100,000 m3/d). For this purpose some of the existing units at both plants were equipped with anaerobic zones which were generated mainly by process modifications. Additionally stage one of the Ruhleben plant was altered completely in order to investigate the combination of biological phosphorus and nitrogen removal as a special pilot study in three parallel trains. The research activities and treatment results gained in each of the two stages of the Ruhleben and in the Marienfelde plant are reported in detail. For example BOD-related phosphorus removal rates were obtained ranging from 2.3-4.5 mg TP per 100 mg BOD removed. It must be stressed that all examinations were performed on full-scale conditions. At present the given limit of 2 mg TP/l in the Ruhleben plant is met without any chemical precipitation at least on average. From the beginning biological phosphorus removal will be integrated into further projected extensions.

scholarly journals MBBR+two-stage AO in upgrading and rebuilding project Of a sewage treatment plant in north China

2019 ◽  
Vol 136 ◽  
pp. 06031
Author(s):  
Shen Dongmei ◽  
Yu Cairui ◽  
Gao Yulan ◽  
Song Xinwei ◽  
Chu Jingsong
Keyword(s):  
High Efficiency ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Oxidation Ditch ◽  
Effluent Quality ◽  
Second Stage ◽  
The North ◽  
Filter Process

A sewage treatment plant is located in the middle of Inner Mongolia. There is a large amount of slaughtering wastewater in the influent with high COD, SS, low annual temperature, poor nitrogen removal effect, and the effluent quality is only grade B. In order to solve the above problems, A\A\O-MBBR + high efficiency sedimentation tank continuous sand filter process was adopted to establish a new anaerobic tank and a first stage AO-MBBR bioreactor. The selection tank and partial oxidation ditch were transformed into the second stage A pool (anoxic pool), and the remaining part of the existing oxidation ditch was transformed into the second stage O pond (aerobic pool), which further removed phosphorus and reduced the SS in the sewage, and solved the problem of low temperature biological treatment in winter in the north of China. The quality of the effluent reached level A after the upgrading.

Influence of Bio-Filter Bed on Treatment of Domestic Sewage in Purifying Tank

2011 ◽  
Vol 183-185 ◽  
pp. 1009-1013
Author(s):  
Chang Wang ◽  
Zhi Cheng Wang ◽  
Bin Fang ◽  
Qing Zhu Jia ◽  
Gui Ju Li
Keyword(s):  
Treatment Process ◽  
Sewage Treatment ◽  
Domestic Sewage ◽  
Mean Values ◽  
Key Technology ◽  
Effluent Quality ◽  
The Mean ◽  
Solid Liquid ◽  
Solid Liquid Separation ◽  
Filter Bed

The influence of bio-filter on domestic sewage treatment in purifying tank was studied in this paper. The result shows that when all the three zones were added bio-filter the mean values of effluent COD and NH3-N were 37.8mg/L and 9.64mg/L respectively, which shows that the bio-filter bed is a key technology and plays important roles for solid-liquid separation, bio-sorption and bio-degradation, to raise the effluent quality in the sewage treatment process.

Feasibility of a pilot-scale UASB/trickling filter system for domestic sewage treatment

2001 ◽  
Vol 44 (4) ◽  
pp. 221-228 ◽  
Author(s):  
C.A.L. Chernicharo ◽  
M.C.P. Nascimento
Keyword(s):  
Sewage Treatment ◽  
Domestic Sewage ◽  
Uasb Reactor ◽  
Trickling Filter ◽  
Treatment Unit ◽  
Promising Alternative ◽  
Operational Conditions ◽  
Belo Horizonte ◽  
Final Effluent ◽  
Bod Removal

This paper presents the results of pilot system comprised of one UASB reactor followed by one trickling filter (TF). The UASB reactor had a volume of 416 litres, being operated at an average hydraulic retention time (HRT) of 4 hours. The trickling filter had a useful volume of 60 litres, being operated at hydraulic and organic loading rates varying from 3.4 to 30.6 m3/m2.d and 0.3 to 3.9 kgBOD/m3.d, respectively. These different operational conditions characterised eight research phases. Both reactors were fed with domestic sewage pumped directly from the main interceptor of Belo Horizonte City, Brazil. After almost 16 months of continuous monitoring, the UASB/TF system produced very good results in terms of COD and BOD removal, and also very low solids concentration in the final effluent. The average results of COD and BOD removal varied from 74 to 88% and from 80 to 94%, respectively, sufficient to maintain the COD concentration in the final effluent in the range of 60 to 120 mg/L and the BOD values systematically below 60 mg/L. The overall averages of SS in the final effluent were kept below 30 mg/L. The UASB/TF system is a very promising alternative for the treatment of domestic sewage in Brazil and other developing countries, since the system can be designed with very short hydraulic retention times, resulting in a very compact and low cost treatment unit. Besides, the energy consumption and the labour costs are minimal.

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