454 pyrosequencing-based characterization of the bacterial consortia in a well established nitrifying reactor

2015 ◽  
Vol 72 (6) ◽  
pp. 990-997 ◽  
Author(s):  
Rocio Ramirez-Vargas ◽  
Nancy Serrano-Silva ◽  
Yendi E. Navarro-Noya ◽  
Rocio J. Alcántara-Hernández ◽  
Marco Luna-Guido ◽  
...  
Keyword(s):  
Extracellular Polymeric Substances ◽  
High Throughput Sequencing ◽  
Removal Rate ◽  
Nitrifying Bacteria ◽  
Organic Load ◽  
Continuous Stirred Tank Reactor ◽  
Bacterial Consortia ◽  
Continuous Stirred Tank ◽  
Planktonic Community

This present study aimed to characterize the bacterial community in a well-established nitrifying reactor by high-throughput sequencing of 16S rRNA amplicons. The laboratory-scale continuous stirred tank reactor has been supplied with ammonium (NH4+) as sole energy source for over 5 years, while no organic carbon has been added, assembling thus a unique planktonic community with a mean NH4+ removal rate of 86 ± 1.4 mg NH4+-N/(L d). Results showed a nitrifying community composed of bacteria belonging to Nitrosomonas (relative abundance 11.0%) as the sole ammonia oxidizers (AOB) and Nitrobacter (9.3%) as the sole nitrite oxidizers (NOB). The Alphaproteobacteria (42.3% including Nitrobacter) were the most abundant class within the Proteobacteria (62.8%) followed by the Gammaproteobacteria (9.4%). However, the Betaproteobacteria (excluding AOB) contributed only 0.08%, confirming that Alpha- and Gammaproteobacteria thrived in low-organic-load environments while heterotrophic Betaproteobacteria are not well adapted to these conditions. Bacteroidetes, known to metabolize extracellular polymeric substances produced by nitrifying bacteria and secondary metabolites of the decayed biomass, was the second most abundant phylum (30.8%). It was found that Nitrosomonas and Nitrobacter sustained a broad population of heterotrophs in the reactor dominated by Alpha- and Gammaproteobacteria and Bacteroidetes, in a 1:4 ratio of total nitrifiers to all heterotrophs.

Kinetic Modeling of Continuous Stirred Tank Reactor - Operating On Distillery Effluent

2020 ◽  
Author(s):  
Dhananjay Mohite ◽  
S.S. Salimath
Keyword(s):  
Volatile Fatty Acids ◽  
Removal Rate ◽  
Oxygen Demand ◽  
Organic Content ◽  
Stirred Tank ◽  
Distillery Effluent ◽  
Continuous Stirred Tank Reactor ◽  
Stirred Tank Reactor ◽  
Tank Reactor ◽  
Continuous Stirred Tank

Abstract To identify the viability and performance, distillery effluent having very high organic content was studied on continuous stirred tank reactor (CSTR). Under different organic loading rates (OLR), optimum conditions for highest chemical oxygen demand (COD) removal and biogas generation was found to be for OLR of 0.10 COD kg /d to 0.11 COD kg /d. Highest COD exertion efficiency was found to be around 73% for OLR of 9.166 kg COD/m3/d when hydraulic retention time (HRT) reduced from 15 to 14 days. Biogas generation was observed to be around 30 L/d with a conversion coefficient of 0.405 and 0.12 volatile fatty acids (VFA) to alkalinity ratio were recorded in this stage. Applying the modified Stovere Kincannon model to the reactor, the maximum removal rate constant (Umax) and saturation value constant (Kb) were found to be 17.123 kg/m3/day, and 33.471 kg/m3/day respectively. These records are predominantly significant, when operating the anaerobic biodigesters for treating the distillery effluent along with the production of biogas as an energy sources. CSTR can effectively be employed in treatment of this effluent however post bio-digestion effluent still contains considerable COD. To meet the pollution norms and standards it needs to be treated further. To understand the complex biological treatment process of this effluent further trials are required to be conducted.

Influence of extracellular polymeric substances on nitrogen removal in an intermittently-aerated membrane bioreactor

2005 ◽  
Vol 51 (11) ◽  
pp. 151-158 ◽  
Author(s):  
H. Nagaoka ◽  
H. Nemoto
Keyword(s):  
Molecular Weight ◽  
Nitrogen Removal ◽  
Extracellular Polymeric Substances ◽  
Removal Rate ◽  
Membrane Surface ◽  
Synthetic Wastewater ◽  
Nitrifying Bacteria ◽  
Gel Chromatography ◽  
Bacterial Cells ◽  
Intermittent Aeration

Influence of EPS on fouling of intermittent aeration MBR reactor (denitrification MBR) was investigated changing intermittent aeration cycle (10 minute-cycle and 120 minute-cycle) in laboratory-scale reactors using synthetic wastewater. EPS were extracted from bacterial cells using cation resin method and molecular weight fractioning of EPS was conducted using gel chromatography. In both of the reactors, nitrogen removal rate was almost 100% after 50th day although DO concentration was not very high during the aerated phase because of accumulation of nitrifying bacteria in the reactors. In the 120 minutes-cycle reactor, trans-membrane pressure increased more rapidly than in the 10 minutes-cycle reactor. The reason might be that EPS of more than 1000 kDa, which are the main fouling substances, are produced more rapidly in the 120 minute-cycle condition. It was also found that three peaks at around 100 kDa, 500 kDa and 2000 kDa are prominent in EPS in intermittent-aeration MBR irrespective of cycle and higher molecular weight EPS are decomposed to smaller molecular weight EPS on membrane surface.

scholarly journals Biological treatment of phenolic wastewater in an anaerobic continuous stirred tank reactor

2013 ◽  
Vol 19 (2) ◽  
pp. 173-179 ◽  
Author(s):  
Taghizade Firozjaee ◽  
Ghasem Najafpour ◽  
Ali Asgari ◽  
Maryam Khavarpour
Keyword(s):  
Biogas Production ◽  
Removal Rate ◽  
Stirred Tank ◽  
Organic Loading Rate ◽  
Phenol Removal ◽  
Continuous Stirred Tank Reactor ◽  
Stirred Tank Reactor ◽  
Tank Reactor ◽  
Phenolic Wastewater ◽  
Continuous Stirred Tank

In the present study, an anaerobic continuous stirred tank reactor (ACSTR) with consortium of mixed culture was operated continuously for a period of 110 days. The experiments were performed with three different hydraulic retention times and by varying initial phenol concentrations between 100 to 1000 mg/L. A maximum phenol removal was observed at a hydraulic retention time (HRT) of 4 days, with an organic loading rate (OLR) of 170.86 mg/L.d. At this condition, phenol removal rate of 89% was achieved. In addition, the chemical oxygen demand (COD) removal corresponds to phenol removal. Additional operating parameters such as pH, MLSS and biogas production rate of the effluents were also measured. The present study provides valuable information to design an anaerobic ACSTR reactor for the biodegradation of phenolic wastewater.

scholarly journals Anaerobic digestion of dairy manure in a fixed bed CSTR: Methane production performance and microbial diversity

BioResources ◽  
2020 ◽  
Vol 15 (4) ◽  
pp. 7965-7979
Author(s):  
Haipeng Wang ◽  
Yiquan Zhao ◽  
Anyi Yang ◽  
Lei Yan ◽  
Teng Teeh Lim ◽  
...  
Keyword(s):  
Methane Production ◽  
Bacterial Communities ◽  
Extracellular Polymeric Substances ◽  
Fixed Bed ◽  
Dairy Manure ◽  
Production Performance ◽  
Stirred Tank ◽  
Continuous Stirred Tank Reactor ◽  
Continuous Stirred Tank ◽  
Microbial Diversities

To improve the fixed bed and continuous stirred-tank reactor (CSTR) technology relative to the rate of treatment of dairy manure (DM), a continuous stirred tank-treated DM with immobilized carrier biofilm was investigated for 20 days (hydraulic retention time (HRT) was 10 d). Methane productivity, biofilm characteristics, and microbial diversities of the biofilm and digestate were measured. The highest content of extracellular polymeric substances (EPS), proteins, and polysaccharides occurred at 15 days of digestion. An agglomeration phenomenon was observed using a scanning electron microscope on the biofilm. This indicated that the biofilm consisting of EPS was stable during the second HRT. Microbial diversities in digestate and carrier biofilm were characterized using a 16S rRNA sequencing technique. Results showed that the dominant bacterial communities were Pseudomonas (17% to 26%), Clostridium (13% to 21%), and Bacteroidetes (7% to 16%), while the archaea communities were Methanocorpusculum (25% to 37%), Methanosarcina (15% to 33%), Methanoculleus (11% to 15%), and Methanosaeta (13% to 18%). The methane production rate was significantly correlated with bacterial communities (Pseudomonas, Clostridium, Altererythrobacter atlanticus), archaeal communities (Methanosarcina, Methanoculleus, Methanosaeta, and Methanoplanus), and biofilm characteristics (chemical oxygen demand (COD) and EPS). These findings showed that a carrier biofilm could efficiently increase methane production.

Operation for Bio-Hydrogen Production of CSTR with Integration of Immobilized and Suspended Cell Process

2014 ◽  
Vol 953-954 ◽  
pp. 949-952 ◽  
Author(s):  
Yue Wang ◽  
Yong Feng Li ◽  
Qiao Yan Li ◽  
Rui Ying Lei
Keyword(s):  
Hydrogen Production ◽  
Microbial Growth ◽  
Hydraulic Retention Time ◽  
Removal Rate ◽  
Acid Resistance ◽  
Continuous Stirred Tank Reactor ◽  
Suspended Cell ◽  
Tank Reactor ◽  
Continuous Stirred Tank ◽  
Cod Removal Rate

A new-styled continuous stirred tank reactor (CSTR) seeded with activated sludge attached onto granular activated carbon (GAC) was developed for raised hydrogen production using diluted grenadine syrup. Emphasis was placed on the hydrogen producing performance and stability of the reactor. It was found that the temperature of (35 ± 1) °C, hydraulic retention time (HRT) of 4h, influent COD of 6000mg/L, the maximum hydrogen production was up 12.06L/d. In addition, though pH decreased to 3.42, the microbial growth still high and COD removal rate reached 50%, demonstrating that the reactor processed the ability of acid resistance.

Characterization of Bio-Hydrogen Production from Carbohydrates with Bacteria Ethanoligenens R3

2010 ◽  
Vol 113-116 ◽  
pp. 1884-1889
Author(s):  
An Ying Jiao ◽  
Yong Feng Li ◽  
Kun Liu ◽  
Bing Liu
Keyword(s):  
Hydrogen Production ◽  
Culture Medium ◽  
Previous Experiment ◽  
Hydrogen Yield ◽  
Continuous Stirred Tank Reactor ◽  
Brown Sugar ◽  
Biogas Yield ◽  
Initial Ph ◽  
Continuous Stirred Tank

An ethanol-based hydrogen producing bacteria Ethanoligenens R3 was isolated from continuous stirred tank reactor used for hydrogen production in previous experiment. Batch culture experiments were operated in this study with the fermentative temperature of 35°C and substrate concentration of 10g/L. The performance of hydrogen production from glucose, brown sugar and starch by Ethanoligenens R3 was investigated. The results show that the optimal substrate used for bio-hydrogen production was glucose with the maximum hydrogen yield of 834 mlH2/L culture. Furthermore, effect of initial pH of the culture medium on hydrogen production was studied. It is demonstrated that Ethanoligenens R3 reached the maximum biogas yield of 1760 ml/L culture with the maximum total VFAs concentration of 3329.39 mg/L at the initial pH of culture medium of 5.5.

scholarly journals Characterization of a 5 Litre Continuous Stirred Tank Reactor

2015 ◽  
Vol 03 (02) ◽  
pp. 25-40 ◽  
Author(s):  
Philomena K. Igbokwe ◽  
Joseph T. Nwabanne ◽  
Samuel Wadzani Gadzama
Keyword(s):  
Stirred Tank ◽  
Continuous Stirred Tank Reactor ◽  
Stirred Tank Reactor ◽  
Tank Reactor ◽  
Continuous Stirred Tank
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