scholarly journals Characterization of the microbial communities responsible for ammonia oxidation in activated sludge systems of municipal wastewater treatment plants

2021 ◽  
Author(s):  
GM Itheshamul Islam
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Community Composition ◽  
Municipal Wastewater ◽  
Ammonia Oxidation ◽  
Amoa Gene ◽  
Ammonia Oxidizing Bacteria ◽  
Municipal Wastewater Treatment ◽  
Operational Parameters ◽  
Activated Sludge System

Nitrification is an essential microbial process in the global nitrogen cycle. The first step of nitrification is ammonia oxidation which is achieved by bacteria and archaea and is crucial in decreasing ammonia concentrations that are persistently high in wastewater. This study examined the composition, abundance and identity of the microbial community in activated sludge with a focus on characterizing ammonia oxidizing bacteria and archaea in a full-scale municipal wastewater treatment plant (MWTP). Specifically, two pharmaceutical compounds Tetracycline and Ibuprofen, and their effects on the community composition of bacteria and protozoa in activated sludge was investigated using PCR coupled with denaturing gradient gel electrophoresis (DGGE). In addition, the composition, abundance and activity of the ammonia oxidizing bacteria (AOB) and ammonia oxidizing archaea (AOA) were analyzed from aerobic activated sludge, recycled sludge and anaerobic digesters of the Humber MWTP using molecular techniques such as PCR, Quantitative PCR, Reverse Transcription-PCR and DGGE. The findings demonstrated that Tetracycline did not appear to alter community composition of bacteria in the activated sludge, rather, the operational parameters of the sequencing batch reactors such as feeding rates and SRT have shown to alter the richness of bacterial communities. However, Ibuprofen affected some members in the protozoan community in activated sludge. In the full-scale Humber MWTP using the conventional activated sludge system, the aeration tanks contained 1.8 × 105 copies of the AOB amoA gene per 100 ng of DNA. In contrast, the anaerobic digester tanks contained 7.3 × 102 copies of the AOA amoA gene per 100ng of DNA. This study also found that AOB were dominant in activated sludge samples, regardless of the operational parameters. The quantification of cDNA transcripts of the amoA gene also indicated that AOB may be more active than AOA in the activated sludge system. Overall, it appears that AOA are very niche specific and thrive in very low oxygenated environments, while AOB proliferate and play a major role in aerobic ammonia oxidation occurring in MWTPs.

scholarly journals Characterization of the microbial communities responsible for ammonia oxidation in activated sludge systems of municipal wastewater treatment plants

2021 ◽  
Author(s):  
GM Itheshamul Islam
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Community Composition ◽  
Municipal Wastewater ◽  
Ammonia Oxidation ◽  
Amoa Gene ◽  
Ammonia Oxidizing Bacteria ◽  
Municipal Wastewater Treatment ◽  
Operational Parameters ◽  
Activated Sludge System

Nitrification is an essential microbial process in the global nitrogen cycle. The first step of nitrification is ammonia oxidation which is achieved by bacteria and archaea and is crucial in decreasing ammonia concentrations that are persistently high in wastewater. This study examined the composition, abundance and identity of the microbial community in activated sludge with a focus on characterizing ammonia oxidizing bacteria and archaea in a full-scale municipal wastewater treatment plant (MWTP). Specifically, two pharmaceutical compounds Tetracycline and Ibuprofen, and their effects on the community composition of bacteria and protozoa in activated sludge was investigated using PCR coupled with denaturing gradient gel electrophoresis (DGGE). In addition, the composition, abundance and activity of the ammonia oxidizing bacteria (AOB) and ammonia oxidizing archaea (AOA) were analyzed from aerobic activated sludge, recycled sludge and anaerobic digesters of the Humber MWTP using molecular techniques such as PCR, Quantitative PCR, Reverse Transcription-PCR and DGGE. The findings demonstrated that Tetracycline did not appear to alter community composition of bacteria in the activated sludge, rather, the operational parameters of the sequencing batch reactors such as feeding rates and SRT have shown to alter the richness of bacterial communities. However, Ibuprofen affected some members in the protozoan community in activated sludge. In the full-scale Humber MWTP using the conventional activated sludge system, the aeration tanks contained 1.8 × 105 copies of the AOB amoA gene per 100 ng of DNA. In contrast, the anaerobic digester tanks contained 7.3 × 102 copies of the AOA amoA gene per 100ng of DNA. This study also found that AOB were dominant in activated sludge samples, regardless of the operational parameters. The quantification of cDNA transcripts of the amoA gene also indicated that AOB may be more active than AOA in the activated sludge system. Overall, it appears that AOA are very niche specific and thrive in very low oxygenated environments, while AOB proliferate and play a major role in aerobic ammonia oxidation occurring in MWTPs.

scholarly journals Different engineering designs have profoundly different impacts on the microbiome and nitrifying bacterial populations in municipal wastewater treatment bioreactors

2021 ◽  
Author(s):  
Taegyu Kim ◽  
Sebastian Behrens ◽  
Timothy LaPara
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Community Composition ◽  
Municipal Wastewater ◽  
Specific Treatment ◽  
Treatment Goals ◽  
Municipal Wastewater Treatment ◽  
Α Diversity ◽  
Treatment Facilities ◽  
System Designs

Numerous wastewater treatment processes are designed by engineers to achieve specific treatment goals. However, the impact of these different process designs on bacterial community composition is poorly understood. In this study, 24 different municipal wastewater treatment facilities (37 bioreactors) with various system designs were analyzed by sequencing of PCR-amplified 16S rRNA gene fragments. Although a core microbiome was observed in all of the bioreactors, the overall microbial community composition (analysis of molecular variance; P = 0.001) as well as a specific population of Nitrosomonas spp. ( P = 0.04) were significantly different between A/O (anaerobic/aerobic) systems and conventional activated sludge (CAS) systems. Community α-diversity (number of observed operational taxonomic units [OTUs] and Shannon diversity index) was also significantly higher in A/O systems compared to CAS systems (Wilcoxon; P < 2 × 10 −16 ). In addition, wastewater bioreactors with short mean cell residence time (< 2 days) had very low community α-diversity and fewer nitrifying bacteria compared to other system designs. Nitrospira spp. (0.71%) and Nitrotoga spp. (0.41%) were the most prominent nitrite oxidizing bacteria (NOB); because these two genera were rarely prominent community members at the same time, these populations appeared to be functionally redundant. Weak evidence (AOB:NOB ≪ 2; substantial quantities of Nitrospira spp. sublineage II) was also obtained suggesting that complete ammonia oxidation by a single organism was occurring in system designs known to impose stringent nutrient limitation. This research demonstrates that design decisions made by wastewater treatment engineers significantly impact the microbiome of wastewater treatment bioreactors. IMPORTANCE Municipal wastewater treatment facilities rely on the application of numerous “activated sludge” process designs to achieve site-specific treatment goals. A plethora of microbiome studies on municipal wastewater treatment bioreactors have been previously performed; however, the role of process design on the municipal wastewater treatment microbiome is poorly understood. In fact, wastewater treatment engineers have attempted to control the microbiome of wastewater bioreactors for decades without sufficient empirical evidence to support their design paradigms. Our research demonstrates that engineering decisions with respect to system design have a significant impact on the microbiome of wastewater treatment bioreactors.

scholarly journals Impact of Flowback Water on Activated Sludge Biocenosis During Municipal Wastewater Treatment

2015 ◽  
Vol 22 (4) ◽  
pp. 611-624 ◽  
Author(s):  
Aleksandra Ziembińska-Buczyńska ◽  
Adam Drzewicki ◽  
Dorota Kulikowska
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Municipal Wastewater ◽  
Prolonged Exposure ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Ammonia Oxidizing Bacteria ◽  
Municipal Wastewater Treatment ◽  
Water Addition ◽  
Flowback Water ◽  
In Series

Abstract The aim of this study was to determine the effect of flowback water on an activated sludge biocenosis during municipal wastewater treatment in the sequencing batch reactors (SBRs). Two series were performed. In series 1, only municipal wastewater was treated, whereas in series 2, municipal wastewater with pre-treated flowback water was used. Flowback water constituted 3-5% of the influent and was introduced to the SBRs twice per week. Introducing flowback water did not decrease the quality of effluent from the SBRs. However, the composition of the activated sludge biocenosis differed between series, ie the biodiversity of protozoa and the relative abundance of microfauna in functional groups changed after flowback water addition. Polymerase chain reaction - denaturing gradient gel electrophoresis (PCR-DGGE) showed that the ammonia oxidizers community responded faster to flowback water addition than the total bacterial community and remained relatively stable during treatment. However, after 9 weeks of exposure to flowback water, ammonia oxidizing bacteria (AOB) biodiversity decreased. This suggests that prolonged exposure could cause nitrification problems, leading to deterioration in effluent quality

scholarly journals High functional diversity among Nitrospira populations that dominate rotating biological contactor microbial communities in a municipal wastewater treatment plant

2019 ◽  
Author(s):  
Emilie Spasov ◽  
Jackson M. Tsuji ◽  
Laura A. Hug ◽  
Andrew C. Doxey ◽  
Laura A. Sauder ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Municipal Wastewater ◽  
Ammonia Oxidation ◽  
Treatment Plant ◽  
16S Rrna Gene Sequencing ◽  
Model Systems ◽  
Rrna Gene ◽  
Ammonia Oxidizing Bacteria ◽  
Municipal Wastewater Treatment ◽  
Nitrite Oxidizers

AbstractNitrification, the oxidation of ammonia to nitrate via nitrite, is an important process in municipal wastewater treatment plants (WWTPs). Members of the Nitrospira genus that contribute to complete ammonia oxidation (comammox) have only recently been discovered and their relevance to engineered water treatment systems is poorly understood. This study investigated distributions of Nitrospira, ammonia-oxidizing archaea (AOA), and ammonia-oxidizing bacteria (AOB) in biofilm samples collected from tertiary rotating biological contactors (RBCs) of a municipal WWTP in Guelph, Ontario, Canada. Using quantitative PCR (qPCR), 16S rRNA gene sequencing, and metagenomics, our results demonstrate that Nitrospira species strongly dominate RBC biofilm samples and that comammox Nitrospira outnumber all other nitrifiers. Genome bins recovered from assembled metagenomes reveal multiple populations of comammox Nitrospira with distinct spatial and temporal distributions, including several taxa that are distinct from previously characterized Nitrospira members. Diverse functional profiles imply a high level of niche heterogeneity among comammox Nitrospira, in contrast to the sole detected AOA representative that was previously cultivated and characterized from the same RBC biofilm. Our metagenome bins also reveal two cyanase-encoding populations of comammox Nitrospira, suggesting an ability to degrade cyanate, which has not been shown previously for Nitrospira that are not strict nitrite oxidizers. This study demonstrates the importance of RBCs as model systems for continued investigation of environmental factors that control the distributions and activities of AOB, AOA, comammox Nitrospira, and other nitrite oxidizers.

Biofiltration as a Compact Technique for Small Waste Water Treatment Plants

1990 ◽  
Vol 22 (3-4) ◽  
pp. 145-152 ◽  
Author(s):  
Gilbert Desbos ◽  
Frank Rogalla ◽  
Jacques Sibony ◽  
Marie-Marguerite Bourbigot
Keyword(s):  
Wastewater Treatment ◽  
Municipal Wastewater ◽  
Ammonia Oxidation ◽  
Wastewater Treatment Plants ◽  
Waste Water Treatment ◽  
Bacterial Degradation ◽  
Municipal Wastewater Treatment ◽  
Operational Parameters ◽  
Removal Rates ◽  
Design Data

Biological aerated filters combine bacterial degradation of pollution by fixed biomass with physical filtration in a single reactor. Removal rates become independent of clarification and sludge setueability limits, and concentration of biomass is increased. Nitrifiers attach to the media, allowing nitrogen removal without sludge age constraints. Several fullsize plants with the BIOCARBONE process for industrial and municipal wastewater treatment have established the compacity, ease of operation and high removal rates achievable with this advanced treatment system. A new biofilter design offering simplified operation and increased performance is presented, which allows implementation of biofiltration for small wastewater treatment plants. Design data for carbon and nutrient removal were collected during extensive pilot tests. Hydraulic conditions and pollution loadings were varied in order to optimize the biological and operational parameters of the filter. The combination of an anaerobic and an aerobic zone eliminates the need for primary sedimentation. Pollution removal rates up to 20 kg COD/m3 d could be achieved, and a widely fluctuating load of up to twice that average loading can be treated without major effluent deterioration. If lower carbon loadings are used, nitrification is achieved in the upper aerated zone. By recirculating the effluent into the non-aerated lower zone, carbon and ammonia oxidation as well as denitrification and suspended solids retention could be achieved with an overall hydraulic retention time of four hours in one reactor.

Factors affecting population of filamentous bacteria in wastewater treatment plants with nutrients removal

2015 ◽  
Vol 73 (4) ◽  
pp. 790-797 ◽  
Author(s):  
Aleksandra Miłobędzka ◽  
Anna Witeska ◽  
Adam Muszyński
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Population Analysis ◽  
Principal Component ◽  
Volume Index ◽  
Filamentous Bacteria ◽  
Municipal Wastewater Treatment ◽  
Operational Parameters

Filamentous population in activated sludge and key operational parameters of full-scale municipal wastewater treatment plants (WWTPs) with bulking problems representative for Poland were investigated with quantitative fluorescence in situ hybridization. Statistical analyses revealed few relationships between operational parameters and biovolume of filamentous bacteria. Sludge age was not only positively correlated with abundance of Chloroflexi (parametric correlation and principal component analysis (PCA)), but also differentiated Microthrix population (analysis of variance (ANOVA)). Phylum Chloroflexi and pH presented a negative relation during the study (PCA). ANOVA showed that pH of influent and sludge volume index (SVI) differentiated abundance of types 0803 and 1851 of Chloroflexi and candidate division TM7. SVI increased along with higher abundance of Microthrix (positive parametric and non-parametric correlations and positive relation in PCA). Biovolumes of morphotypes 0803 and 1851 of Chloroflexi were differentiated by organic matter in influent, also by nutrients in the case of Chloroflexi type 1851. Chemical and biological oxygen demands (COD and BOD5, respectively) were negatively correlated with Microthrix. COD also differentiated the abundance of Haliscomenobacter hydrossis. Results of the study can be used to prevent WWTPs from excessive proliferation of filamentous bacteria and operational problems caused by them – bulking and foaming of activated sludge.

Molecular assessment of ammonia- and nitrite-oxidizing bacteria in full-scale activated sludge wastewater treatment plants

2003 ◽  
Vol 48 (8) ◽  
pp. 119-126 ◽  
Author(s):  
K.G. Robinson ◽  
H.M. Dionisi ◽  
G. Harms ◽  
A.C. Layton ◽  
I.R. Gregory ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
16S Rdna ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Amoa Gene ◽  
Full Scale ◽  
Ammonia Oxidizing Bacteria ◽  
Copy Numbers ◽  
Nitrite Oxidizing Bacteria

Nitrification was assessed in two full-scale wastewater treatment plants (WWTPs) over time using molecular methods. Both WWTPs employed a complete-mix suspended growth, aerobic activated sludge process (with biomass recycle) for combined carbon and nitrogen treatment. However, one facility treated primarily municipal wastewater while the other only industrial wastewater. Real time PCR assays were developed to determine copy numbers for total 16S rDNA (a measure of biomass content), the amoA gene (a measure of ammonia-oxidizers), and the Nitrospira 16S rDNA gene (a measure of nitrite-oxidizers) in mixed liquor samples. In both the municipal and industrial WWTP samples, total 16S rDNA values were approximately 2-9 × 1013 copies/L and Nitrospira 16S rDNA values were 2-4 × 1010 copies/L. amoA gene concentrations averaged 1.73 × 109 copies/L (municipal) and 1.06 × 1010 copies/L (industrial), however, assays for two distinct ammonia oxidizing bacteria were required.

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