Nitrogen removal from wastewater in a pilot plant operated in the recirculation anoxic-oxic activated sludge mode

1996 ◽  
Vol 33 (12) ◽  
pp. 255-258 ◽  
Author(s):  
Olga Burica ◽  
Marjeta Strazar ◽  
Ivan Mahne
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plant ◽  
Pilot Plant ◽  
Municipal Wastewater ◽  
Treatment Plant ◽  
Volume Ratio ◽  
Mineral Nitrogen ◽  
Operating Conditions ◽  
Effluent Quality

The recirculation activated sludge process with preanoxic treatment was applied for biological reduction of the nitrogen content in municipal wastewater at pilot plant level. The pilot plant of total volume 3 300 1 with an initial anoxic to aerobic volume ratio of 40 : 60 was fed with wastewater from the first heavily loaded aerobic stage of a local wastewater treatment plant. Experiments were run over the summer and winter periods, the influent wastewater temperature being approx 24°C and approx 10°C, respectively. Special attention was paid to the hydraulic retention time, the total as well as mineral nitrogen loading, the aerobic to anaerobic volume ratio, and to the energy demand for denitrification of oxidised mineral nitrogen forms. Under optimal operating conditions the effluent quality that could be achieved was about 10 mg/l of total nitrogen (74% removal) and less than 2 mg N/l mineral nitrogen (87% removal), while simultaneously 205 mg BOD5/l in the influent was reduced to less than 7mg O2/l in the effluent. It was found feasible from the pilot plant experiments to upgrade an existing two stage aerobic-anaerobic wastewater treatment plant to reduce nitrogen from the liquid fraction of municipal wastewater so as to meet effluent quality standards without much additional volume and without amending the energy source for bioconversion of oxidised mineral nitrogen to gaseous forms.

scholarly journals Time-series genome-centric analysis unveils bacterial response to operational disturbance in activated sludge

2019 ◽  
Author(s):  
María Victoria Pérez ◽  
Leandro D. Guerrero ◽  
Esteban Orellana ◽  
Eva L. Figuerola ◽  
Leonardo Erijman
Keyword(s):  
Growth Rate ◽  
Time Series ◽  
Wastewater Treatment ◽  
Activated Sludge ◽  
Microbial Communities ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Operating Conditions ◽  
The Face

ABSTRACTUnderstanding ecosystem response to disturbances and identifying the most critical traits for the maintenance of ecosystem functioning are important goals for microbial community ecology. In this study, we used 16S rRNA amplicon sequencing and metagenomics to investigate the assembly of bacterial populations in a full-scale municipal activated sludge wastewater treatment plant over a period of three years, including a period of nine month of disturbance, characterized by short-term plant shutdowns. Following the reconstruction of 173 metagenome-assembled genomes, we assessed the functional potential, the number of rRNA gene operons and thein situgrowth rate of microorganisms present throughout the time series. Operational disturbances caused a significant decrease in bacteria with a single copy of the ribosomal RNA (rrn) operon. Despite only moderate differences in resource availability, replication rates were distributed uniformly throughout time, with no differences between disturbed and stable periods. We suggest that the length of the growth lag phase, rather than the growth rate, as the primary driver of selection under disturbed conditions. Thus, the system could maintain its function in the face of disturbance by recruiting bacteria with the capacity to rapidly resume growth under unsteady operating conditions.IMPORTANCEIn this work we investigated the response of microbial communities to disturbances in a full-scale activated sludge wastewater treatment plant over a time-scale that included periods of stability and disturbance. We performed a genome-wide analysis, which allowed us the direct estimation of specific cellular traits, including the rRNA operon copy number and the in situ growth rate of bacteria. This work builds upon recent efforts to incorporate growth efficiency for the understanding of the physiological and ecological processes shaping microbial communities in nature. We found evidence that would suggest that activated sludge could maintain its function in the face of disturbance by recruiting bacteria with the capacity to rapidly resume growth under unsteady operating conditions. This paper provides relevant insights into wastewater treatment process, and may also reveal a key role for growth traits in the adaptive response of bacteria to unsteady environmental conditions.

Intermittent feeding of wastewater in combination with alternating aeration for complete denitrification and control of filaments

2010 ◽  
Vol 61 (9) ◽  
pp. 2259-2266 ◽  
Author(s):  
Styliani Kantartzi ◽  
Paraschos Melidis ◽  
Alexander Aivasidis
Keyword(s):  
Wastewater Treatment ◽  
Total Nitrogen ◽  
Nitrogen Removal ◽  
Wastewater Treatment Plant ◽  
Municipal Wastewater ◽  
Settling Tank ◽  
Treatment Plant ◽  
Operating Conditions ◽  
Anoxic Conditions ◽  
Total Nitrogen Removal

In the present study, a laboratory scale system, consisting of a primary settling tank, a continuous stirred tank reactor and a clarifier were constructed and operated, using wastewater from the municipal wastewater treatment plant in Xanthi, Greece. The system operated under intermittent aeration in aerobic/anoxic conditions and feeding of the wastewater once in every cycle. The unit was inoculated with sludge, which originated from the recirculation stream of the local wastewater treatment plant. The wastewater was processed with hydraulic retention time (HRT) of 12 h, in which various experimental states were studied regarding the combination of aerobic and anoxic intervals. The wastewater was fed in limited time once in every cycle of aerobic/anoxic conditions at the beginning of the anoxic period. The two states that exhibited highest performance in nitrification and total nitrogen removal were, then, repeated with HRT of 10 h. The results show that, regarding the nitrification stage and the organic load removal, the intermittent system achieved optimum efficiency, with an overall removal of biological oxygen demand (BOD5) and ammonium nitrogen in the range of 93–96% and 91–95% respectively. As far as the total nitrogen removal is concerned, and if the stage of the denitrification is taken into account, the performance of the intermittent system surpassed other methods, as it is shown by the total Kjeldahl nitrogen (TKN) removal efficiency of 85–87%. These operating conditions suppressed the growth of filamentous organisms, a fact reflected at the SVI values, which were lower than 150 ml/g.

Suspended carrier technology allows upgrading high-rate activated sludge plants for nitrogen removal via process intensification

2000 ◽  
Vol 41 (4-5) ◽  
pp. 5-12 ◽  
Author(s):  
E.v. Münch ◽  
K. Barr ◽  
S. Watts ◽  
J. Keller
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Residence Time ◽  
Nitrogen Removal ◽  
Wastewater Treatment Plant ◽  
Pilot Plant ◽  
Treatment Plant ◽  
Carbon Removal ◽  
Suspended Carrier ◽  
Plastic Media

The Oxley Creek wastewater treatment plant is a conventional 185,000 EP BOD removal activated sludge plant that is to be upgraded for nitrogen removal to protect its receiving water bodies, the Brisbane River and Moreton Bay. Suspended carrier technology is one possible way of upgrading this activated sludge wastewater treatment plant for nitrogen removal. Freely moving plastic media is added to the aeration zone, providing a growth platform for nitrifying bacteria and increasing the effective solids residence time (SRT). This paper presents the results from operating a pilot plant for 7 months at the Oxley Creek WWTP in Brisbane, Australia. Natrix Major 12/12 plastic media, developed by ANOX (Lund, Sweden), was trialed in the pilot plant. The pilot plant was operated with a mixed liquor suspended solids concentration of 1220 mg/L and a total hydraulic residence time of 5.4 hours, similar to the operating conditions in the full-scale Stage 1&2 works at the Oxley Creek WWTP. The plastic carriers were suspended in the last third of the bioreactor volume, which was aerated to a DO setpoint of 4.0 mg/L. The first third of the bioreactor volume was made anoxic and the second third served for carbon removal, being aerated to a DO setpoint of 0.5 mg/L. The results from the pilot plant indicate that an average effluent total inorganic nitrogen concentration (ammonia-N plus NOx−N) of less than 12 mg/L is possible. However, the effluent ammonia concentrations from the pilot plant showed large weekly fluctuations due to the intermittent operation of the sludge dewatering centrifuge returning significant ammonia loads to the plant on three days of the week. Optimising denitrification was carried out by lowering the DO concentration in the influent and in the carbon removal reactor. The results from the pilot plant study show that the Oxley Creek WWTP could be upgraded for nitrogen removal without additional tankage, using suspended carrier technology.

scholarly journals Biochemical Hydrogen Potential Tests Using Different Inocula

2019 ◽  
Vol 11 (3) ◽  
pp. 622 ◽  
Author(s):  
Isabella Pecorini ◽  
Francesco Baldi ◽  
Renato Iannelli
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plant ◽  
Municipal Wastewater ◽  
Treatment Plant ◽  
Municipal Wastewater Treatment ◽  
Digested Sludge ◽  
Anaerobic Reactor ◽  
Municipal Wastewater Treatment Plant ◽  
Solids Removal

Four inocula collected from different operating facilities were tested in their hydrogenic performances by means of two biochemical hydrogen potential test set-ups using sucrose and food waste as substrates, with the aim of evaluating the influence of inoculum media in batch fermentative assays. The selected inocula were: activated sludge collected from the aerobic unit of a municipal wastewater treatment plant, digested sludge from an anaerobic reactor treating organic waste and cattle manure, digested sludge from an anaerobic reactor treating agroindustrial residues, and digested sludge from an anaerobic reactor of a municipal wastewater treatment plant. Test results, in terms of specific hydrogen production, hydrogen conversion efficiency, and volatile solids removal efficiency, were significantly dependent on the type of inoculum. Statistical analysis showed different results, indicating that findings were due to the different inocula used in the tests. In particular, assays performed with activated sludge showed the highest performances for both substrates and both experimental set-ups.

Experience with Two-Stage Activated Sludge Plants for Industrial Wastewaters in Korea

1992 ◽  
Vol 25 (4-5) ◽  
pp. 427-428 ◽  
Author(s):  
R. Schulze-Rettmer ◽  
S. S. Kim ◽  
S. S. Son
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plant ◽  
Pilot Plant ◽  
Treatment Plant ◽  
Activated Sludge Process ◽  
Two Stage ◽  
Industrial Wastewaters ◽  
Textile Dyeing ◽  
One Year

The two-stage activated sludge process (AB-process, i.e. adsorption activated sludge process) invented by Boehnke was successfully applied to several municipal and industrial wastewaters in Korea. The first large wastewater treatment plant for the combined effluents of 22 textile dyeing companies was constructed in Taegu and started operation in 1989. Two years earlier pilot plant runs were performed. The AB-process proved to be superior to any other activated sludge process. BOD was reduced from 1200 mg/l down to 24 mg/l. In the meantime in Korea several further AB-process treatment plants were constructed, the overall planning and constructing period being not longer than one year.

Decentralized Adaptive PI with Adaptive Interaction Algorithm of Wastewater Treatment Plant

2014 ◽  
Vol 67 (5) ◽  
Author(s):  
M. F. Rahmat ◽  
S. I. Samsudin ◽  
N. A. Wahab ◽  
Mashitah Che Razali ◽  
Muhammad Sani Gaya
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plant ◽  
Error Function ◽  
Treatment Plant ◽  
Weather Conditions ◽  
Pi Controller ◽  
Effluent Quality ◽  
Dynamic Performances ◽  
Adaptive Interaction

Wastewater treatment plant (WWTP) is highly known with the variation and uncertainty of the parameters, making them a challenge to be tuned and controlled. In this paper, an adaptive decentralized PI controller is developed for nonlinear activated sludge WWTP. The work is highlighted in auto-tuning the PI control parameters in satisfying straighten effluent quality and hence optimizing the nitrogen removal. The PI controller parameters are obtained by using simple updating algorithm developed based on adaptive interaction theory. The error function is minimized directly by approximate Frechet tuning algorithm without explicit estimation of the model. The effectiveness of the proposed controller is then validated by comparing the performance of activated sludge process to the benchmark PI under three different weather conditions with realistic variations in influent flow rate and composition. The algorithm is effectively applied in activated sludge system with improved dynamic performances in effluent quality index and energy consumed of Benchmark Simulation Model No.1.

scholarly journals Time Series Genome-Centric Analysis Unveils Bacterial Response to Operational Disturbance in Activated Sludge

mSystems ◽  
2019 ◽  
Vol 4 (4) ◽  
Author(s):  
María Victoria Pérez ◽  
Leandro D. Guerrero ◽  
Esteban Orellana ◽  
Eva L. Figuerola ◽  
Leonardo Erijman
Keyword(s):  
Growth Rate ◽  
Time Series ◽  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Full Scale ◽  
Operating Conditions ◽  
Lag Phase

ABSTRACT Understanding ecosystem response to disturbances and identifying the most critical traits for the maintenance of ecosystem functioning are important goals for microbial community ecology. In this study, we used 16S rRNA amplicon sequencing and metagenomics to investigate the assembly of bacterial populations in a full-scale municipal activated sludge wastewater treatment plant over a period of 3 years, including a 9-month period of disturbance characterized by short-term plant shutdowns. Following the reconstruction of 173 metagenome-assembled genomes, we assessed the functional potential, the number of rRNA gene operons, and the in situ growth rate of microorganisms present throughout the time series. Operational disturbances caused a significant decrease in bacteria with a single copy of the rRNA (rrn) operon. Despite moderate differences in resource availability, replication rates were distributed uniformly throughout time, with no differences between disturbed and stable periods. We suggest that the length of the growth lag phase, rather than the growth rate, is the primary driver of selection under disturbed conditions. Thus, the system could maintain its function in the face of disturbance by recruiting bacteria with the capacity to rapidly resume growth under unsteady operating conditions. IMPORTANCE Disturbance is a key determinant of community assembly and dynamics in natural and engineered ecosystems. Microbiome response to disturbance is thought to be influenced by bacterial growth traits and life history strategies. In this time series observational study, the response to disturbance of microbial communities in a full-scale activated sludge wastewater treatment plant was assessed by computing specific cellular traits of genomes retrieved from metagenomes. It was found that the genomes observed in disturbed periods have more copies of the rRNA operon than genomes observed in stable periods, whereas the in situ mean relative growth rates of bacteria present during stable and disturbed periods were indistinguishable. From these intriguing observations, we infer that the length of the lag phase might be a growth trait that affects the microbial response to disturbance. Further exploration of this hypothesis could contribute to better understanding of the adaptive response of microbiomes to unsteady environmental conditions.

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