Comparison of bench scale testing methods for nitrifier growth rate measurement

2002 ◽  
Vol 46 (1-2) ◽  
pp. 289-295 ◽  
Author(s):  
D. Katehis ◽  
J. Fillos ◽  
L.A. Carrio
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Exponential Growth ◽  
Wastewater Treatment Plants ◽  
Batch Reactors ◽  
Sequencing Batch Reactors ◽  
Rate Measurement ◽  
Testing Methods ◽  
Batch Tests ◽  
Growth Rate Measurement

The maximum specific nitrifier growth rate was determined for two wastewater treatment plants (WWTPs) using sequencing batch reactors (SBRs) and high F/M exponential growth batch tests. Higher nitrifier growth rates were obtained from the exponential growth batch tests. Operating SRT and aeration mode (fully aerobic versus anoxic/aerobic) significantly impacted the nitrifier's growth rate in the SBRs with lower SRT and anoxic/aerobic operation resulting in higher specific nitrifier growth rates.

Microbiote shift in sequencing batch reactors in response to antimicrobial ZnO nanoparticles

RSC Advances ◽  
2016 ◽  
Vol 6 (111) ◽  
pp. 110108-110111 ◽  
Author(s):  
Zhenghui Liu ◽  
Huifang Zhou ◽  
Jiefeng Liu ◽  
Xudong Yin ◽  
Yufeng Mao ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Wastewater Treatment ◽  
Adverse Effects ◽  
Zno Nanoparticles ◽  
Zinc Oxide Nanoparticles ◽  
Wastewater Treatment Plants ◽  
Oxide Nanoparticles ◽  
Batch Reactors ◽  
Sequencing Batch Reactors ◽  
Zno Nps

Zinc oxide nanoparticles (ZnO NPs) have been monitored in wastewater treatment plants as their potential adverse effects on functional microorganisms have been causing increasing concern.

scholarly journals Contribution of prokaryotes and eukaryotes to CO2 emissions in the wastewater treatment process

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9325
Author(s):  
Katarzyna Jaromin-Gleń ◽  
Roman Babko ◽  
Tatiana Kuzmina ◽  
Yaroslav Danko ◽  
Grzegorz Łagód ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Greenhouse Effect ◽  
Wastewater Treatment Plants ◽  
Ghg Emissions ◽  
Batch Reactors ◽  
Sequencing Batch Reactors ◽  
Wastewater Treatment Process ◽  
Eukaryotic Organisms ◽  
Quantitative Contribution

Reduction of the greenhouse effect is primarily associated with the reduction of greenhouse gas (GHG) emissions. Carbon dioxide (CO2) is one of the gases that increases the greenhouse effect - it is responsible for about half of the greenhouse effect. Significant sources of CO2 are wastewater treatment plants (WWTPs) and waste management, with about 3% contribution to global emissions. CO2 is produced mainly in the aerobic stage of wastewater purification and is a consequence of activated sludge activity. Although the roles of activated sludge components in the purification process have been studied quite well, their quantitative contribution to CO2 emissions is still unknown. The emission of CO2 caused by prokaryotes and eukaryotes over the course of a year (taking into account subsequent seasons) in model sequencing batch reactors (SBR) is presented in this study. In this work, for the first time, we aimed to quantify this contribution of eukaryotic organisms to total CO2 emissions during the WWTP process. It is of the order of several or more ppm. The contribution of CO2 produced by different components of activated sludge in WWTPs can improve estimation of the emissions of GHGs in this area of human activity.

Balancing yield, kinetics and cost for three external carbon sources used for suspended growth post-denitrification

2009 ◽  
Vol 60 (10) ◽  
pp. 2485-2491 ◽  
Author(s):  
Y. Mokhayeri ◽  
R. Riffat ◽  
S. Murthy ◽  
W. Bailey ◽  
I. Takacs ◽  
...  
Keyword(s):  
Wastewater Treatment Plants ◽  
Carbon Sources ◽  
The United States ◽  
Batch Reactors ◽  
Sequencing Batch Reactors ◽  
Process Step ◽  
Stringent Limit ◽  
Receiving Waters ◽  
Set Up

Facilities across North America are designing plants to meet stringent limit of technology (LOT) treatment for nitrogen removal. In the Mid-Atlantic region of the United States, this is in response to the Chesapeake Bay Agreement, which limit effluent total nitrogen discharges from wastewater treatment plants to between 3–5 mg/L. Since denitrification is crucial for the removal of nitrogen, maximizing this process step will result in a decrease in nutrient load to the receiving waters. Of particular interest is the use of an alternate external carbon source to replace the most commonly used carbon, methanol. Three external carbon sources were evaluated in this study including: methanol, ethanol and acetate at 13°C. The aim of this study was to evaluate the relative benefits and constraints for using these three carbon types. Laboratory scale Sequencing Batch Reactors (SBRs) were set up to grow and acclimate carbon free biomass to the specified substrate while in-situ Specific Denitrification Rates (SDNRs) were conducted concurrently. The results suggest that the SDNRs for acetate (31.0 ± 4.6 mgNO3-N/gVSS/hr) and ethanol (29.6 ± 5.6 mgNO3-N/gVSS/hr) are higher than that for methanol (10.1 ± 2.5 mgNO3-N/gVSS/hr). The yield coefficients in g COD/g COD were observed to follow a similar trend with values of 0.45 ± 0.05 for methanol, 0.53 ± 0.06 for ethanol and 0.66 ± 0.06 for acetate.

Role of biomass adaptation in the removal of formic acid in sequencing batch reactors

2008 ◽  
Vol 58 (2) ◽  
pp. 303-307 ◽  
Author(s):  
D. Dionisi ◽  
M. Majone ◽  
A. Bellani ◽  
C. Cruz Viggi ◽  
M. Beccari
Keyword(s):  
Acetic Acid ◽  
Formic Acid ◽  
Microbial Growth ◽  
Batch Reactors ◽  
Sequencing Batch Reactors ◽  
Batch Tests ◽  
Treatment Processes ◽  
Classical Models ◽  
Activated Sludge Processes

This study deals with formic acid removal in activated sludge processes, in particular in the processes carried out in sequencing batch reactors (SBRs). Formic acid removal has been investigated in a SBR fed with acetic and formic acids at equimolar concentrations. Biomass performance in the reactor has been investigated both by the analysis of the removal of the two substrates and by batch tests. Regarding SBR process, the obtained results show that a relevant difference occurred between formic and acetic acid profiles. Acetic acid was never found in the effluent and was always completely removed during the reaction phase. On the other hand, formic acid removal was determined by biomass acclimation, which is in turn determined by sludge age imposed to the system. Batch tests confirmed that formic acid removal occurs only if biomass is acclimated. It has been shown that the minimal sludge age to obtain complete formic acid removal is much higher than those predictable with the classical models of microbial growth in wastewater treatment processes. The advantages of SBRs over continuous-flow systems in the removal of formic acid have also been highlighted.

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