Microbiology of Nutrient Removing Activated Sludge

1982 ◽  
Vol 14 (9-11) ◽  
pp. 1501-1502 ◽  
Author(s):  
Margaret A Hart ◽  
Leah N Melmed
Keyword(s):  
Activated Sludge ◽  
Nutrient Removal ◽  
Negative Group ◽  
Gram Negative ◽  
Start Up ◽  
Removal System

The modified Bardenpho nutrient removal system is described. The build-up of microbiological life from plant start-up is recorded and Aoinetobaoter spp is identified as a major component of the Gram-negative group of bacteria in a number of plants. Problems with filamentous organisms are described.

Verification of anoxic phosphate uptake as the main biochemical mechanism of the “dephanox” process

1997 ◽  
Vol 35 (10) ◽  
pp. 87-94 ◽  
Author(s):  
R. Sorm ◽  
J. Wanner ◽  
R. Saltarelli ◽  
G. Bortone ◽  
A. Tilche
Keyword(s):  
Activated Sludge ◽  
Nutrient Removal ◽  
Uptake Rate ◽  
Phosphate Uptake ◽  
Biochemical Mechanism ◽  
Batch Experiments ◽  
Batch Tests ◽  
Genetic Probes ◽  
Activated Sludge Systems ◽  
Removal System

The phenomenon of anoxic phosphate uptake with simultaneous denitrification was studied. For this purpose kinetic batch tests have been carried out by using the activated sludge samples from three modifications of nutrient removal activated sludge systems: two based on an anaerobic-anoxic-oxic (A2/O) system and a third on an anaerobic-oxic (A/O) system. The results showed significant differences in anoxic phosphate uptake rate between activated sludge which was alternatively exposed to anoxic conditions and activated sludge from the A/O arrangement. These differences were also accompanied by different denitrification rates. Simultaneously with batch experiments the microscopic observation of activated sludge samples was carried out. Neisser and Gram stained samples showed clear differences in shape, size and distribution of polyphosphate accumulating bacteria between A2/O and A/O Processes. Moreover, experiments performed using genetic probes confirmed the differences in microbiological composition of activated sludge samples from different nutrient removal system arrangements.

Start-Up and Cultivation of A2N Denitrifying Phosphorus and Nitrogen Removal System

2012 ◽  
Vol 610-613 ◽  
pp. 1454-1458
Author(s):  
Ming Fen Niu ◽  
Hong Jing Jiao ◽  
Li Xu ◽  
Yan Yu ◽  
Jian Wei
Keyword(s):  
Activated Sludge ◽  
Removal Efficiency ◽  
Total Nitrogen ◽  
Nitrogen Removal ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Nitrogen And Phosphorus ◽  
Start Up ◽  
Two Phases ◽  
Removal System

A2N is two-sludge system, by using the method that first bringing up the cultivation of denitrifying phosphorus removing bacteria (DPB) and nitrification biofilm separately then connecting them, which can start up A2N system successfully. Nitrification biofilm was cultivated in a sequencing batch reactor (SBR). After 30 days, NH4+-N effluent concentration steadily stayed below 0.5mg·L-1.In another SBR, the activated sludge for the enrichment of DPB is from the anaerobic tank, which was firstly operated under anaerobic/aerobic (A/O) condition. After 20 days, PAOs was successfully enriched. Then, the activated sludge was conducted under anaerobic/anoxic/aerobic (A/A/O) condition, maintaining the anaerobic time, gradually increased anoxic time and induced aerobic time. After 30 days DPB was successfully enriched, two phases totally take 50 days. The removal efficiency of total nitrogen and phosphorus are above 85 % and 95 %, so that A2N system was started up successfully.

Microscopic Evaluation of Carbon and Phosphorus Accumulation in Nutrient Removal Activated Sludge Plants

1988 ◽  
Vol 20 (4-5) ◽  
pp. 37-49 ◽  
Author(s):  
Laurraine H. Lötter ◽  
Margaret Murphy
Keyword(s):  
Activated Sludge ◽  
Nutrient Removal ◽  
Phosphorus Removal ◽  
Start Up ◽  
Microscopic Evaluation ◽  
Phosphorus Accumulation ◽  
Rapid Formation ◽  
Large Clusters ◽  
Aerobic Zone ◽  
Extracellular Slime

Successful phosphorus removal by a nutrient removal activated sludge plant, depends ultimately on the ability of the biomass to store carbon in the form of polyhydroxybutyrate and phosphate as polyphosphate. This study has shown that floc-forming cells in the aerobic zone of an efficient phosphorus removing plant contain large polyphosphate inclusions, and are usually larger in size than anaerobic zone cells. Monitoring the development of biomass in a new activated sludge plant by seeding with mixed liquor from the Johannesburg Goudkoppies Works, demonstrated the rapid formation of a typical activated sludge floc. The distinct differences between polyhydroxybutyrate and polyphosphate storage in the anaerobic, anoxic and aerobic zones observed in Goudkoppies sludge were however, not evident in the new plant until two weeks after start-up and the large clusters of polyphosphate containing bacteria were not observed until even later. The formation of large clusters of bacteria observed in phosphorus removing plants was considered contingent on the production of extracellular slime. This was borne out by the examination of various plants for the presence of extracellular slime, which revealed that the presence of this material correlates well with satisfactory phosphorus removal.

The effect of reactor configuration and operational mode on Microthrix parvicella bulking and foaming in nutrient removal activated sludge systems

2002 ◽  
Vol 46 (1-2) ◽  
pp. 61-64 ◽  
Author(s):  
C. Noutsopoulos ◽  
D. Mamais ◽  
A.D. Andreadakis
Keyword(s):  
Activated Sludge ◽  
Nutrient Removal ◽  
Plug Flow ◽  
Selective Advantage ◽  
Operational Mode ◽  
Intermittent Aeration ◽  
Reactor Configuration ◽  
Microthrix Parvicella ◽  
Activated Sludge Systems ◽  
Removal System

Three bench-scale nutrient removal activated sludge units were used to examine the effect of the reactor configuration and the intermittent aeration mode on the growth of Microthrix parvicella. According to the results, the plug flow configuration seems to achieve satisfactory Microthrix parvicella control. The imposed concentration gradient for both RBCOD and SBCOD creates a selective advantage for the floc forming bacteria throughout the system (both the anoxic and oxic zones) and limits Microthrix parvicella growth. In terms of the operational mode, the intermittent aeration CSTR nutrient removal system promotes the growth of M.parvicella and deteriorates the settling characteristics of the activated sludge.

Development of the microbial community of a full scale biological nutrient removal activated sludge plant during start-up

1995 ◽  
Vol 29 (9) ◽  
pp. 2085-2093 ◽  
Author(s):  
G.C. Knight ◽  
E.M. Seviour ◽  
R.J. Seviour ◽  
J.A. Soddell ◽  
K.C. Lindrea ◽  
...  
Keyword(s):  
Microbial Community ◽  
Activated Sludge ◽  
Nutrient Removal ◽  
Full Scale ◽  
Biological Nutrient Removal ◽  
Start Up

Modeling the biotransformation of trimethoprim in biological nutrient removal system

2018 ◽  
Vol 2017 (1) ◽  
pp. 144-155
Author(s):  
Olumuyiwa O. Ogunlaja ◽  
Wayne J. Parker
Keyword(s):  
Activated Sludge ◽  
Nutrient Removal ◽  
Pilot Scale ◽  
Biological Nutrient Removal ◽  
Ammonia Oxidizing Bacteria ◽  
Nitrification Inhibition ◽  
Batch Tests ◽  
Microbial Groups ◽  
Polyphosphate Accumulating Organisms ◽  
Removal System

Abstract A pilot scale biological nutrient removal (BNR) process, batch experiments and modeling exercises were employed to investigate the removal and biotransformation of trimethoprim (TMP) in a BNR activated sludge process. The concentrations of the active microbial groups – ammonia oxidizing bacteria (AOB), ordinary heterotrophic organisms (OHOs) and polyphosphate accumulating organisms (PAOs) – in the BNR bioreactor were quantified through modeling of the pilot bioreactor. The overall TMP removal efficiency for the pilot BNR process was 64 ± 14% while the TMP biotransformation efficiencies in the anaerobic, anoxic and aerobic zones were 22 ± 20%, 27 ± 8% and 36 ± 5% respectively. Batch tests with and without nitrification inhibition showed that AOB played a role in the biotransformation of TMP in BNR activated sludge. A pseudo first order model which incorporated the contributions of PAOs, OHOs and AOB to the overall biodegradation of TMP was found to describe the biodegradation of TMP in batch tests with and without nitrification inhibition. This model showed that PAOs, OHOs and AOB contributed towards the biotransformation of TMP in aerobic BNR activated sludge with the biotransformation rate constants following the trend of kAOB > kOHOs > kPAOs.

scholarly journals Start-up of a nutrient removal system using Scenedesmus vacuolatus and Chlorella vulgaris biofilms

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Jairo Hernán Moreno Osorio ◽  
Gabriele Pinto ◽  
Antoninio Pollio ◽  
Luigi Frunzo ◽  
Piet Nicolaas Luc Lens ◽  
...  
Keyword(s):  
Chlorella Vulgaris ◽  
Nutrient Removal ◽  
Scenedesmus Vacuolatus ◽  
Start Up ◽  
Removal System

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.

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.

Denitrification in a Carbon and Nitrogen Removal System for Leachate Treatment: Performance of a Upflow Sludge Blanket (USB) Reactor

1999 ◽  
Vol 40 (8) ◽  
pp. 145-151 ◽  
Author(s):  
Liliana Borzacconi ◽  
Gisela Ottonello ◽  
Elena Castelló ◽  
Heber Pelaez ◽  
Augusto Gazzola ◽  
...  
Keyword(s):  
Complete System ◽  
Carbon Sources ◽  
Uasb Reactor ◽  
Leachate Treatment ◽  
N Removal ◽  
Start Up ◽  
Aerobic Reactor ◽  
C And N ◽  
Reactor Operating ◽  
Removal System

The performance of a bench scale upflow sludge bed (USB) denitrifying reactor was evaluated in order to integrate it into a C and N removal system for Sanitary Landfill Leachate. The raw leachate used presented COD and NH4-N average values of 30000 mg/l and 1000 mg/l, respectively. The complete system comprises in addition an UASB reactor and a nitrifying RBC. A portion of the aerobic reactor effluent was recycled into the denitrification stage and some raw leachate was also added as an additional C source. In order to obtain operating parameters the denitrifying reactor was operated alone. Sludge from an aerobic reactor (RBC) treating raw leachate was used as inoculum. Shortly after the start up, good granulation of the sludge bed was observed. Using raw leachate and UASB outlet as carbon sources with COD/NO3-N ratios of 4 and 12, respectively, denitrification efficiencies of about 90% were reached. A sludge yield of 0.16 gVSS/gCODremoved was obtained operating with raw leachate. For the anoxic reactor operating in the complete system, denitrification efficiencies of 90% were also achieved. A nitrogen gas recycle was a successful way to avoid frequently observed sludge bed rising problems.

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