Characterizing denitrification kinetics at cold temperature using various carbon sources in lab-scale sequencing batch reactors

2008 ◽  
Vol 58 (1) ◽  
pp. 233-238 ◽  
Author(s):  
Yalda Mokhayeri ◽  
Rumana Riffat ◽  
Imre Takacs ◽  
Peter Dold ◽  
Charles Bott ◽  
...  
Keyword(s):  
Chesapeake Bay ◽  
Wastewater Treatment Plants ◽  
Inorganic Nitrogen ◽  
Carbon Sources ◽  
Ex Situ ◽  
Batch Reactors ◽  
Sequencing Batch Reactors ◽  
Denitrification Kinetics ◽  
Internal Sources ◽  
Set Up

Wastewater treatment plants in the Chesapeake Bay region are becoming more interested in external carbon sources for denitrification. This is in response to the recent regulations to remediate the Chesapeake Bay, which will limit effluent total nitrogen to near 3 mg/L for plants, thus requiring near complete elimination of inorganic nitrogen species. Since sufficient internal carbon is usually not available for complete denitrification, external carbon is needed to supplement internal sources. Of particular interest is the use of an alternate external carbon source to replace the least expensive source methanol. This study focuses on three commonly available external carbon sources: methanol, ethanol and acetate. The aim of this study was to obtain the specific denitrification rate (SDNR) of the substrates under several conditions. Sequencing batch reactors (SBRs) were set up to first grow biomass to the specified substrate while in situ SDNRs were conducted concurrently. Once the biomass was grown with the corresponding substrate, a series of ex situ SDNRs were performed using various biomass/substrate combinations to evaluate response to substrate combinations at 13°C. Results from this study indicate that the SDNRs for biomass grown on methanol, ethanol and acetate were 9.2 mg NO3-N/g VSS/hr, 30.4 mg NO3-N/gVSS/hr and 31.7 mg NO3-N/g VSS/hr, respectively, suggesting that acetate and ethanol were equally effective external carbon sources followed by much lower SDNR using methanol. Ethanol could be used with methanol biomass with similar rates as that of methanol. Additionally, methanol was rapidly acclimated to ethanol grown biomass suggesting that the two substrates could be interchanged to grow respective populations with a minimum lag period.

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.

scholarly journals Effect of Salinity on Cr(VI) Bioremediation by Algal-Bacterial Aerobic Granular Sludge Treating Synthetic Wastewater

Processes ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 1400
Author(s):  
Bach Van Nguyen ◽  
Xiaojing Yang ◽  
Shota Hirayama ◽  
Jixiang Wang ◽  
Ziwen Zhao ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Wastewater Treatment Plants ◽  
Inorganic Nitrogen ◽  
Granular Sludge ◽  
Synthetic Wastewater ◽  
Aerobic Granular Sludge ◽  
Batch Reactors ◽  
Sequencing Batch Reactors ◽  
Conventional Activated Sludge ◽  
Total Inorganic Nitrogen

Heavy metal-containing wastewater with high salinity challenges wastewater treatment plants (WWTPs) where the conventional activated sludge process is widely applied. Bioremediation has been proven to be an effective, economical, and eco-friendly technique to remove heavy metals from various wastewaters. The newly developed algal-bacterial aerobic granular sludge (AGS) has emerged as a promising biosorbent for treating wastewater containing heavy metals, especially Cr(VI). In this study, two identical cylindrical sequencing batch reactors (SBRs), i.e., R1 (Control) and R2 (with 1% additional salinity), were used to cultivate algal-bacterial AGS and then to evaluate the effect of salinity on the performance of the two SBRs. The results reflected that less filamentation and a rougher surface could be observed on algal-bacterial AGS when exposed to 1% salinity, which showed little influence on organics removal. However, the removals of total inorganic nitrogen (TIN) and total phosphorus (TP) were noticeably impacted at the 1% salinity condition, and were further decreased with the co-existence of 2 mg/L Cr(VI). The Cr(VI) removal efficiency, on the other hand, was 31–51% by R1 and 28–48% by R2, respectively, indicating that salinity exposure may slightly influence Cr(VI) bioremediation. In addition, salinity exposure stimulated more polysaccharides excretion from algal-bacterial AGS while Cr(VI) exposure promoted proteins excretion.

scholarly journals Investigation of Biotransformation Products of p-Methoxymethylamphetamine and Dihydromephedrone in Wastewater by High-Resolution Mass Spectrometry

Metabolites ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 66
Author(s):  
Juliet Kinyua ◽  
Aikaterini K. Psoma ◽  
Nikolaos I. Rousis ◽  
Maria-Christina Nika ◽  
Adrian Covaci ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Wastewater Treatment Plants ◽  
High Resolution Mass Spectrometry ◽  
Transformation Products ◽  
New Psychoactive Substances ◽  
Batch Reactors ◽  
Flight Mass Spectrometry ◽  
Detection And Identification ◽  
Wastewater Samples ◽  
Set Up

There is a paucity of information on biotransformation and stability of new psychoactive substances (NPS) in wastewater. Moreover, the fate of NPS and their transformation products (TPs) in wastewater treatment plants is not well understood. In this study, batch reactors seeded with activated sludge were set up to evaluate biotic, abiotic, and sorption losses of p-methoxymethylamphetamine (PMMA) and dihydromephedrone (DHM) and identify TPs formed during these processes. Detection and identification of all compounds was performed with target and suspect screening approaches using liquid chromatography quadrupole-time-of-flight mass spectrometry. Influent and effluent 24 h composite wastewater samples were collected from Athens from 2014 to 2020. High elimination rates were found for PMMA (80%) and DHM (97%) after a seven-day experiment and degradation appeared to be related to biological activity in the active bioreactor. Ten TPs were identified and the main reactions were O- and N-demethylation, oxidation, and hydroxylation. Some TPs were reported for the first time and some were confirmed by reference standards. Identification of some TPs was enhanced by the use of an in-house retention time prediction model. Mephedrone and some of its previously reported human metabolites were formed from DHM incubation. Retrospective analysis showed that PMMA was the most frequently detected compound.

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.

Sequencing batch reactor as a post-treatment of anaerobically treated dairy effluent

2006 ◽  
Vol 54 (2) ◽  
pp. 199-206 ◽  
Author(s):  
A. Benítez ◽  
A. Ferrari ◽  
S. Gutierrez ◽  
R. Canetti ◽  
A. Cabezas ◽  
...  
Keyword(s):  
Batch Reactor ◽  
Anaerobic Treatment ◽  
Post Treatment ◽  
Operating Conditions ◽  
Batch Reactors ◽  
Sequencing Batch Reactors ◽  
Operational Parameters ◽  
Reactor Operation ◽  
Set Up ◽  
The Stability

Wastewater from dairy industries, characterized by its high COD content and relative high COD/TKN ratio, requires post-treatment after anaerobic treatment to complete the removal of organic matter and nutrients. Due to its simplicity, robustness and low maintenance costs, sequencing batch reactors (SBR) result in an attractive system, especially in case of small dairy industries in order to comply with the emission standards. The goal of this work was to determine the operational parameters, optimize the performance, and study the stability of the microbial population of a SBR system for the post-treatment of an anaerobic pond effluent. High and stable removal of COD and TKN was achieved in the reactor, which can easily be set up in dairy industries. An active nitrifying population was selected during reactor operation and maintained relatively stable, while the heterotrophic (total and denitrifying) communities were more unstable and susceptible to changes in the operating conditions.

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