Upgrading for nitrogen removal under severe site restrictions

1998 ◽  
Vol 37 (9) ◽  
pp. 185-192 ◽  
Author(s):  
P. Balmér ◽  
L. Ekfjorden ◽  
D. Lumley ◽  
A. Mattsson
Keyword(s):  
Activated Sludge ◽  
Nitrogen Removal ◽  
Plant Design ◽  
Trickling Filter ◽  
Process Selection ◽  
Trickling Filters ◽  
Plant Area ◽  
Highly Loaded

The Rya WWTP in Göteborg, Sweden is a highly loaded activated sludge plant which has been upgraded to remove nitrogen and to increase the biologically treated flow by 33% to reduce bypassing. Severe site restrictions made it difficult to increase the plant area. This was solved using a compant process based on tertiary nitrification in trickling filters and recirculation to a highly loaded activated sludge unit for denitrification. The necessary volumes were achieved by expanding the plant upwards, thus making it possible to place the trickling filters a in part of the area occupied by the former aeration basins. The recirculation of trickling filter effluent made it necessary to double the secondary settler capacity. This was solved by retrofitting the existing settlers as stacked settlers with a second tray on top of the original basin. The considerations behind process selection and plant design and costs are described.

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.

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.

Dynamics in maximal settling capacity in an activated sludge treatment plant with highly loaded secondary settlers

2004 ◽  
Vol 50 (7) ◽  
pp. 187-194 ◽  
Author(s):  
B.-M. Wilén ◽  
D. Lumley ◽  
A. Nordqvist
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Treatment Plant ◽  
Secondary Effluent ◽  
Sludge Treatment ◽  
Trickling Filters ◽  
Secondary Settling ◽  
Determining Factor ◽  
Maximal Capacity ◽  
Highly Loaded

Secondary settling dynamics at maximal capacity were investigated at a full scale wastewater treatment plant which utilizes a unique process solution incorporating pre-denitrification with postnitrification in nitrifying trickling filters. Since nitrogen removal is greater when more secondary effluent is recirculated to the trickling filters, the secondary settlers generally operate at close to their maximal capacity. The settling and flocculation properties of the activated sludge are therefore a major capacity-determining factor for plant operation. Due to the short sludge age, the flocculation properties, with respect to both thickening and clarification, can change quickly. The dynamics in these changes were studied and the factors that determine the maximal settling capacity were assessed. Solids flux curves were constructed from batch settling tests and compared with the actual maximal settling capacities.

New Trickling Filter Applications in the U.S.A.

1990 ◽  
Vol 22 (1-2) ◽  
pp. 215-226 ◽  
Author(s):  
D. S. Parker ◽  
M. P. Lutz ◽  
A. M. Pratt
Keyword(s):  
Activated Sludge ◽  
Poor Quality ◽  
Trickling Filter ◽  
Trickling Filters ◽  
The Poor ◽  
Activated Sludge System ◽  
New Applications ◽  
The U.S

After falling in disfavor in the U.S. in the 1970s, trickling filters are now reappearing in new applications. The Trickling Filter/Solids Contact (TF/SC) process uses physical and biological flocculation features to transform the poor quality of the trickling filter effluent into an effluent equal to the best activated sludge system. Over 50 TF/SC plants have been built since the process was introduced in 1979. The recent development (1988) of the Biofilm-Controlled Nitrifying Trickling Filter (BCNTF) has permitted higher rate operation and rendered the process less costly than the activated sludge system for nitrification. Three BCNTF projects are now underway in the U.S.

scholarly journals Nitrogen Removal in a Full-Scale Domestic Wastewater Treatment Plant with Activated Sludge and Trickling Filter

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Davood Nourmohammadi ◽  
Mir-Bager Esmaeeli ◽  
Hossein Akbarian ◽  
Mohammad Ghasemian
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Total Nitrogen ◽  
Nitrogen Removal ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Treated Wastewater ◽  
Trickling Filter ◽  
High Concentration ◽  
Nitrogen Gas

During the last decade, more stringent effluent requirements concerning the nutrients effluent values have been imposed by legislation and social concern. In this study, efficiency of total nitrogen removal in activated sludge and trickling filter processes (AS/TF) was investigated in Tehran North wastewater treatment plant. Biological system in this site was included, anoxic selector tank, aeration tank, final sedimentation, and trickling filter. A part of treated wastewater before chlorination was mixed with supernatant of dewatered sludge and fed to the trickling filter. Supernatant of dewatered sludge with high concentration of NH4-N was diluted by treated wastewater to provide complete nitrification in trickling filter Produced nitrate in trickling filter was arrived to the anoxic tank and converted to nitrogen gas by denitrification. According to the study result, low concentration of organic carbone and high concentration of NH4-N led to nitrification in TF, then nitrate denitrification to nitrogen gas occurred in selector area. NH4-N concentration decreased from 26.8 mg/L to 0.29 mg/L in TF, and NO3-N concentration increased from 8.8 mg/L to 27 mg/L in TF. Consequently, the total nitrogen decreased approximately to 50% in biological process. This efficiency has been observed in returned flow around 24% from final sedimentation into TF. It was concluded that, in comparison with biological nutrient removal processes, this process is very efficient and simple.

Occurrence and reduction of pharmaceuticals in the water phase at Swedish wastewater treatment plants

2012 ◽  
Vol 66 (4) ◽  
pp. 783-791 ◽  
Author(s):  
P. Falås ◽  
H. R. Andersen ◽  
A. Ledin ◽  
J. la Cour Jansen
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Nitrogen Removal ◽  
Biological Treatment ◽  
Wastewater Treatment Plants ◽  
Trickling Filter ◽  
Screening Programs ◽  
Research Institutes ◽  
Influent Water ◽  
Human Usage

During the last decade, several screening programs for pharmaceuticals at Swedish wastewater treatment plants (WWTPs) have been conducted by research institutes, county councils, and wastewater treatment companies. In this study, influent and effluent concentrations compiled from these screening programs were used to assess the occurrence and reduction of non-antibiotic pharmaceuticals for human usage. The study is limited to full-scale WWTPs with biological treatment. Based on the data compiled, a total of 70 non-antibiotic pharmaceuticals have been detected, at concentrations ranging from a few ng/L to several μg/L, in the influent water. The influent concentrations were compared with the sale volumes and for many pharmaceuticals it was shown that only a small fraction of the amount sold reaches WWTPs as dissolved parent compounds. Pharmaceuticals with low reduction degrees at traditional WWTPs were identified. Further comparison based on the biological treatment showed lower reduction degrees for several pharmaceuticals in trickling filter plants compared with activated sludge plants with nitrogen removal.

Operating Experience with Plastic Media Tertiary Trickling Filters for Nitrification

1984 ◽  
Vol 16 (10-11) ◽  
pp. 201-213 ◽  
Author(s):  
W Gujer ◽  
M Boiler
Keyword(s):  
Steady State ◽  
Activated Sludge ◽  
Operating Experience ◽  
Trickling Filter ◽  
Trickling Filters ◽  
Pilot Experience ◽  
Multi Media ◽  
Cost Efficient ◽  
Approach To Steady State ◽  
Activated Sludge Processes

Based on 20 months of pilot experience the following aspects of operation of a nitrifying tertiary trickling filter are discussed: Biomass production, biomass predation, approach to steady state, load variation, alkalinity, stability of performance, nitrite, temperature and nitrification in multi media filtration. Nitrification in tertiary trickling filters proved to be easy to operate, stable in performance and cost efficient in comparison with activated sludge processes.

Upgrading of existing trickling filter plants for denitrification

1994 ◽  
Vol 30 (6) ◽  
pp. 173-179 ◽  
Author(s):  
G. F. Mehlhart
Keyword(s):  
European Union ◽  
Activated Sludge ◽  
Nutrient Removal ◽  
Fixed Bed ◽  
Design Criteria ◽  
Trickling Filter ◽  
Trickling Filters ◽  
Fixed Bed Reactors ◽  
Nitrogen Elimination ◽  
Activated Sludge Systems

New European Union Guidelines ask for nutrient removal. For trickling filters it was necessary to develop new design criteria for denitrification. The paper presents the results of half-scaled and full-scaled experiments with activated sludge systems, fixed bed reactors prepositioned and postpositioned. Further results out of literature are added. Possible design criteria are shown. It is emphasized that some trickling filters show simultanous nitrogen elimination of up to 80 %.

Trickling filters for upgrading low technology wastewater plants for nitrogen removal

2004 ◽  
Vol 49 (11-12) ◽  
pp. 47-52 ◽  
Author(s):  
P. Pearce
Keyword(s):  
Total Nitrogen ◽  
Nitrogen Removal ◽  
Original Data ◽  
Significant Degree ◽  
Primary Treatment ◽  
Trickling Filter ◽  
Trickling Filters ◽  
Water Region ◽  
Filter Process ◽  
The Uk

Previous work through the 1990s in the Thames Water region in the UK has demonstrated the ability of the trickling filter process to produce fully nitrified effluents, reliably throughout the year. The original data used for the nitrification model derivations have been reanalysed, to investigate the degree of nitrogen removal across the process. Removals of total nitrogen ranging from 0% to over 50% were observed across the trickling filter process and calculated total nitrogen removals of 26-63% were obtained when primary treatment was included. The degree of nitrogen removal and biological denitrification (excluding cellular assimilation) was found to be strongly influenced by BOD load, irrigation velocity and media size. Regression models were produced which gave good predictive relationships for the data ranges used. The models produced worked for filters used with and without a recirculation of effluent nitrate which suggests that a significant degree of nitrification occurred in areas of high heterotroph activity (BOD removal). The simplicity and energy efficiency of the trickling filter process, combined with its capacity for full nitrification and partial denitrification, make the process attractive as a combined process used with pond systems in developing countries where nitrogen removal may be required. Some of these synergies have already been developed with the PETRO® process in South Africa.

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