scholarly journals Impact on nitrifiers of full-scale bioaugmentation

2017 ◽  
Vol 76 (11) ◽  
pp. 3079-3085 ◽  
Author(s):  
F. Stenström ◽  
J. la Cour Jansen

Abstract Nitrifiers are the slowest growing bacteria used in conventional biological wastewater treatment. Furthermore, their growth rate is seriously hampered by low temperature. As a result, the volume needed for nitrification dominates the volume of the biological reactors at a wastewater treatment plant. As a way of enhancing nitrification and reducing this volume, bioaugmentation can be used. Nitrifiers from a side-stream plant can be inoculated to the mainstream process, which is thereby boosted. The effect of bioaugmentation can be measured in different ways. This full-scale study focuses on the effect of bioaugmentation from a microbial point of view by using 16S rRNA amplicon sequencing. The study reveals how bioaugmentation increases the diversity of nitrifiers in the mainstream process and in the side-stream plant; that the abundance of nitrifiers is increased in the mainstream process; the interaction between nitrifiers from the side-stream plant and mainstream process; and the effect of bioaugmentation on nitrifying genera and species over time. To our knowledge, this detailed microbial information on nitrifying species during a full-scale bioaugmentation study has not been presented before.

2013 ◽  
Vol 67 (11) ◽  
pp. 2519-2526 ◽  
Author(s):  
A. T. Mielczarek ◽  
A. M. Saunders ◽  
P. Larsen ◽  
M. Albertsen ◽  
M. Stevenson ◽  
...  

Since 2006 more than 50 Danish full-scale wastewater treatment plants with nutrient removal have been investigated in a project called ‘The Microbial Database for Danish Activated Sludge Wastewater Treatment Plants with Nutrient Removal (MiDas-DK)’. Comprehensive sets of samples have been collected, analyzed and associated with extensive operational data from the plants. The community composition was analyzed by quantitative fluorescence in situ hybridization (FISH) supported by 16S rRNA amplicon sequencing and deep metagenomics. MiDas-DK has been a powerful tool to study the complex activated sludge ecosystems, and, besides many scientific articles on fundamental issues on mixed communities encompassing nitrifiers, denitrifiers, bacteria involved in P-removal, hydrolysis, fermentation, and foaming, the project has provided results that can be used to optimize the operation of full-scale plants and carry out trouble-shooting. A core microbial community has been defined comprising the majority of microorganisms present in the plants. Time series have been established, providing an overview of temporal variations in the different plants. Interestingly, although most microorganisms were present in all plants, there seemed to be plant-specific factors that controlled the population composition thereby keeping it unique in each plant over time. Statistical analyses of FISH and operational data revealed some correlations, but less than expected. MiDas-DK (www.midasdk.dk) will continue over the next years and we hope the approach can inspire others to make similar projects in other parts of the world to get a more comprehensive understanding of microbial communities in wastewater engineering.


2016 ◽  
Vol 74 (7) ◽  
pp. 1736-1743 ◽  
Author(s):  
F. Stenström ◽  
J. la Cour Jansen

Bioaugmentation of nitrifiers from a side-stream treatment is an efficient method for boosting the mainstream process at a wastewater treatment plant (WWTP). Although this technology has been known for several years, the number of full-scale applications for it is limited. For a WWTP approaching its critical nitrogen load capacity, the benefits are doubled if the introduced side-stream treatment for digester supernatant is combined with bioaugmentation. Not only is the nitrogen load to the mainstream process decreased by 10–25%, but the mainstream process is also boosted with nitrifiers, increasing the nitrifying capacity. In this full-scale study, the increment of the nitrification rate is examined in the mainstream process at different temperatures and at different flow rates of returned activated sludge to the side-stream treatment. Our results show that the nitrification rate in the mainstream process was increased by 41% during the coldest period of the study, implying that the examined WWTP could treat considerably higher nitrogen loads if bioaugmentation were permanently installed.


mSystems ◽  
2019 ◽  
Vol 4 (4) ◽  
Author(s):  
María Victoria Pérez ◽  
Leandro D. Guerrero ◽  
Esteban Orellana ◽  
Eva L. Figuerola ◽  
Leonardo Erijman

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.


2020 ◽  
Vol 53 (1) ◽  
pp. 208-213
Author(s):  
E.S.S. Tejaswini ◽  
Soniya Panjwani ◽  
G. Uday Bhaskar Babu ◽  
A. Seshagiri Rao

2016 ◽  
Vol 49 (7) ◽  
pp. 1163-1168 ◽  
Author(s):  
Michela Mulas ◽  
Francesco Corona ◽  
Jukka Sirviö ◽  
Seppo Hyvönen ◽  
Riku Vahala

PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0255836
Author(s):  
Shuyuan Deng ◽  
Bo Wang ◽  
Wenda Zhang ◽  
Sanbao Su ◽  
Hao Dong ◽  
...  

Oil-produced wastewater treatment plants, especially those involving biological treatment processes, harbor rich and diverse microbes. However, knowledge of microbial ecology and microbial interactions determining the efficiency of plants for oil-produced wastewater is limited. Here, we performed 16S rDNA amplicon sequencing to elucidate the microbial composition and potential microbial functions in a full-scale well-worked offshore oil-produced wastewater treatment plant. Results showed that microbes that inhabited the plant were diverse and originated from oil and marine associated environments. The upstream physical and chemical treatments resulted in low microbial diversity. Organic pollutants were digested in the anaerobic baffled reactor (ABR) dominantly through fermentation combined with sulfur compounds respiration. Three aerobic parallel reactors (APRs) harbored different microbial groups that performed similar potential functions, such as hydrocarbon degradation, acidogenesis, photosynthetic assimilation, and nitrogen removal. Microbial characteristics were important to the performance of oil-produced wastewater treatment plants with biological processes.


2012 ◽  
Vol 7 (1) ◽  
Author(s):  
S. S. Fatima ◽  
S. Jamal Khan

In this study, the performance of wastewater treatment plant located at sector I-9 Islamabad, Pakistan, was evaluated. This full scale domestic wastewater treatment plant is based on conventional activated sludge process. The parameters which were monitored regularly included total suspended solids (TSS), mixed liquor suspended solids (MLSS), mixed liquor volatile suspended solids (MLVSS), biological oxygen demand (BOD), and chemical oxygen demand (COD). It was found that the biological degradation efficiency of the plant was below the desired levels in terms of COD and BOD. Also the plant operators were not maintaining consistent sludge retention time (SRT). Abrupt discharge of MLSS through the Surplus Activated sludge (SAS) pump was the main reason for the low MLSS in the aeration tank and consequently low treatment performance. In this study the SRT was optimized based on desired MLSS concentration between 3,000–3,500 mg/L and required performance in terms of BOD, COD and TSS. This study revealed that SRT is a very important operational parameter and its knowledge and correct implementation by the plant operators should be mandatory.


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