scholarly journals Minimization of N2O Emission through Intermittent Aeration in a Sequencing Batch Reactor (SBR): Main Behavior and Mechanism

Water ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 210
Author(s):  
Tang Liu ◽  
Shufeng Liu ◽  
Shishi He ◽  
Zhichao Tian ◽  
Maosheng Zheng
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plants ◽  
Batch Reactor ◽  
Quantitative Polymerase Chain Reaction ◽  
N2o Emission ◽  
Ammonia Oxidizer ◽  
Batch Reactors ◽  
Intermittent Aeration ◽  
Major Pathway ◽  
Nitrifier Denitrification

To explore the main behavior and mechanism of minimizing nitrous oxide (N2O) emission through intermittent aeration during wastewater treatment, two lab-scale sequencing batch reactors operated at intermittently aerated mode (SBR1), and continuously aerated mode (SBR2) were established. Compared with SBR2, the intermittently aerated SBR1 reached not only a higher total nitrogen removal efficiency (averaged 93.5%) but also a lower N2O-emission factor (0.01–0.53% of influent ammonia), in which short-cut nitrification and denitrification were promoted. Moreover, less accumulation and consumption of polyhydroxyalkanoates, a potential endogenous carbon source promoting N2O emission, were observed in SBR1. Batch experiments revealed that nitrifier denitrification was the major pathway generating N2O while heterotrophic denitrification played as a sink of N2O, and SBR1 embraced a larger N2O-mitigating capability. Finally, quantitative polymerase chain reaction results suggested that the abundant complete ammonia oxidizer (comammox) elevated in the intermittently aerated environment played a potential role in avoiding N2O generation during wastewater treatment. This work provides an in-depth insight into the utilization of proper management of intermittent aeration to control N2O emission from wastewater treatment plants.

scholarly journals Efficient nitrification and low N2O emission in a weakly acidic bioreactor at low dissolved oxygen levels are due to comammox

2021 ◽  
Author(s):  
Deyong Li ◽  
Fang Fang ◽  
Guoqiang Liu
Keyword(s):  
Wastewater Treatment ◽  
Dissolved Oxygen ◽  
Greenhouse Gas ◽  
N2o Emission ◽  
Low Energy ◽  
Emission Source ◽  
Ammonia Oxidizer ◽  
Ammonia Oxidizing Bacteria ◽  
Nitrifier Denitrification ◽  
Low Do

Nitrification is an essential process for nutrient removal from wastewater and an important emission source of nitrous-oxide (N2O), which is a powerful greenhouse gas and a dominant ozone-depleting substance. In this study, nitrification and N2O emissions were tested in two weakly acidic (pH = 6.3–6.8) reactors: one with dissolved oxygen (DO) over 2.0 mg/L and the other with DO approximately 0.5 mg/L. Efficient nitrification was achieved in both reactors. Compared to the high-DO reactor, N2O emission in the low-DO reactor decreased slightly by 20% and had insignificant correlation with the fluctuations of DO (P = 0.935) and nitrite (P = 0.713), indicating that N2O might not be mainly produced via nitrifier denitrification. Based on qPCR, qFISH, functional gene amplicon and metagenome sequencing, it was found that complete ammonia oxidizer (comammox) Nitrospira significantly outnumbered canonical ammonia-oxidizing bacteria (AOB) in both weakly acidic reactors, especially in the low DO reactor with the comammox/AOB amoA gene ratio increasing from 6.6 to 17.1. Therefore, it was speculated that the enriched comammox was the primary cause for the slightly decreased N2O emission under long-term low DO in weakly acidic reactor. This study demonstrated that comammox Nitrospira can survive well under the weakly acidic and low-DO conditions, implying that achieving efficient nitrification with low N2O emission as well as low energy and alkalinity consumption is feasible for wastewater treatment. Importance Nitrification in wastewater treatment is an important process for eutrophication control and an emission source for greenhouse gas of N2O. The nitrifying process is usually operated at a slightly alkaline pH and high DO (>2 mg/L) to ensure efficient nitrification. However, it consumes a large amount of energy and chemicals especially for wastewater without sufficient alkalinity. This manuscript demonstrated that comammox can adapt well to the weakly acidic and low-DO bioreactors, with a result of efficient nitrification and low N2O emission. These findings indicate that comammox are significant for sustainable wastewater treatment, which provides an opportunity to achieve efficient nitrification with low N2O production as well as low energy and chemical consumption simultaneously.

N2O emission from full-scale urban wastewater treatment plants: a comparison between A2O and SBR

2013 ◽  
Vol 67 (9) ◽  
pp. 1887-1893 ◽  
Author(s):  
Shichang Sun ◽  
Xiang Cheng ◽  
Sha Li ◽  
Fei Qi ◽  
Yan Liu ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Sequencing Batch Reactor ◽  
Wastewater Treatment Plants ◽  
Batch Reactor ◽  
N2o Emission ◽  
Full Scale ◽  
Urban Wastewater ◽  
N2o Flux ◽  
Oxic Zone ◽  
Urban Wastewater Treatment

The emission of nitrous oxide (N2O) from full-scale anoxic/anaerobic/oxic (A2O) and sequencing batch reactor (SBR) processes was measured to evaluate N2O emission from urban wastewater treatment plants (WWTPs). The results showed that N2O flux in the A2O WWTP followed an order of A2O-oxic zone > aerated grit tank >> A2O-anaerobic zone > A2O-anoxic zone > final clarifier > primary clarifier, while in the SBR WWTP the order was SBR tank >> swirl grit tank > wastewater distribution tank and within the SBR tank in an order of SBR-feeding period > SBR-aeration period > SBR-settling period > SBR-decanting period. N2O emission from the A2O WWTP was approximately 486.61 kg d−1, 96.9% of which was from the A2O-oxic zone. In the SBR WWTP, the emission of N2O was 339.24 kg d−1 with 99.9% of the total emission coming from the periods of feeding and aeration. There was 6.52% of nitrogen-load in the influent being transformed to the emitted N2O in the SBR WWTP; the percentage was 3.35 times higher than that in the A2O WWTP.

Sequencing Batch Reactors for Nutrient Removal at Small Wastewater Treatment Plants

1993 ◽  
Vol 28 (10) ◽  
pp. 233-242 ◽  
Author(s):  
Bjorn Rusten ◽  
Helge Eliassen
Keyword(s):  
Wastewater Treatment ◽  
Nutrient Removal ◽  
Wastewater Treatment Plants ◽  
Batch Reactor ◽  
Treatment Plant ◽  
Batch Reactors ◽  
Sequencing Batch Reactors ◽  
Biological Phosphorus Removal ◽  
Solids Retention ◽  
Co Precipitation

In order to optimize the sequencing batch reactor (SBR) process for nutrient removal at small wastewater treatment plants, a two year study was carried out at a treatment plant designed for 300 population equivalents. Different operating cycles, solids retention times (SRTs) and periods with co-precipitation were included in the test program. Based on the results, recommendations for achieving nitrification, denitrification and biological phosphorus removal were given. A suitable coagulant (and the optimum dosage) for co-precipitation was found as well.

scholarly journals Occurrence of SARS-CoV-2 RNA in Six Municipal Wastewater Treatment Plants at the Early Stage of COVID-19 Pandemic in The United States

Pathogens ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 798
Author(s):  
Samendra P. Sherchan ◽  
Shalina Shahin ◽  
Jeenal Patel ◽  
Lauren M. Ward ◽  
Sarmila Tandukar ◽  
...  
Keyword(s):  
United States ◽  
Wastewater Treatment ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Quantitative Polymerase Chain Reaction ◽  
The United States ◽  
Secondary Effluent ◽  
Untreated Wastewater ◽  
Treatment Processes ◽  
Wastewater Samples

In this study, we investigated the occurrence of Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) RNA in primary influent (n = 42), secondary effluent (n = 24) and tertiary treated effluent (n = 34) collected from six wastewater treatment plants (WWTPs A–F) in Virginia (WWTP A), Florida (WWTPs B, C, and D), and Georgia (WWTPs E and F) in the United States during April–July 2020. Of the 100 wastewater samples analyzed, eight (19%) untreated wastewater samples collected from the primary influents contained SARS-CoV-2 RNA as measured by reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) assays. SARS-CoV-2 RNA were detected in influent wastewater samples collected from WWTP A (Virginia), WWTPs E and F (Georgia) and WWTP D (Florida). Secondary and tertiary effluent samples were not positive for SARS-CoV-2 RNA indicating the treatment processes in these WWTPs potentially removed SARS-CoV-2 RNA during the secondary and tertiary treatment processes. However, further studies are needed to understand the log removal values (LRVs) and transmission risks of SARS-CoV-2 RNA through analyzing wastewater samples from a wider range of WWTPs.

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 Nitrogen and Phosphorous Removal in Municipal Wastewater Treatment Plants in China: A Review

2010 ◽  
Vol 2010 ◽  
pp. 1-10 ◽  
Author(s):  
Yong Qiu ◽  
Han-chang Shi ◽  
Miao He
Keyword(s):  
Wastewater Treatment ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Batch Reactor ◽  
Water Environment ◽  
Optimization Techniques ◽  
Municipal Wastewater Treatment ◽  
Real Time Control ◽  
Operational Optimization ◽  
Municipal Wastewater Treatment Plants

Surface water environment in China was degraded rapidly in the last two decades, resulting in increasingly tighten criteria issued for municipal wastewater treatment plants (WWTPs). This paper reviewed the recent advances of process design and operational optimization for nutrients removal. Three major processes, as anaerobic-anoxic-oxic (AAO) process, oxidation ditch (OD), and sequencing batch reactor (SBR) occupied 65% of WWTPs amounts and 54% of treatment volumes of China in 2006. However conservative process designs and operational faults often impaired the process performances and energy efficiency. Therefore, typical processes were modified, combined, and innovated to meet the requirements of the diverse influent characteristics and lower energy consumptions. Furthermore, operational optimization techniques by modeling, simulation, and real-time control were also developed and applied in China to improve the process operation. Although great efforts had been contributed to improve the WWTPs performances in China, attentions should be continuously paid to the introduction, instruction, and implementation of advanced techniques. At last, the technical demands and appropriated techniques of WWTPs in China were briefly discussed.

scholarly journals Methods of reconstruction and modification of the sequencing batch reactor at municipal wastewater treatment plants in Vietnam

Vestnik MGSU ◽  
2019 ◽  
pp. 589-602 ◽  
Author(s):  
Tran Ha Quan ◽  
Elena S. Gogina
Keyword(s):  
Wastewater Treatment ◽  
Sequencing Batch Reactor ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Batch Reactor ◽  
Municipal Wastewater Treatment ◽  
Wastewater Purification ◽  
Municipal Wastewater Treatment Plants ◽  
Operation Cycle

Introduction. Vietnamese urban municipal wastewater treatment plants are mainly of aeration-type facilities. Nowadays, an aeration-type plant, the Sequencing Batch Reactor (SBR), is widely applied and possesses a number of advantages over traditional systems with suspended activated sludge. Advantages of the SBR are mainly concluded in simplicity of operation, occupied area and cost. There is a number of problems at the wastewater treatment plants; they are connected with supplying only a half of wastewater design amount for the treatment as well as with quality of the purified water that must satisfy requirements of the Vietnamese discharge standard, the Standard A. Therefore, reconstruction and modification of the SBR is the major challenger to ensure the sustained development of large Vietnamese cities and maintenance of ecological balance. Materials and methods. To enhance the efficiency of wastewater purification in the SBR, the experiments were set on reactor reconstruction and modification by two directions: (1) Technological method, i.e. applying the Biochip 25 biocarrier, and (2) Operation method, i.e. adding the anoxic phase in reactor operation cycle. Laboratory tests were conducted for each of the directions, including comparison of a typical reactor with the modified one. Results. The study resulted in obtaining an optimal amount of the BioChip biocarrier material (10 to 20 %) that increased efficiency of wastewater purification by 10 to 20 %. In addition to this, when creating an anoxic phase of the operation cycle, efficiency of nitrogen removal increased by 20 %. When the denitrification occurs under the anoxic conditions, it contributes to stabilization of ammonium nitrogen removal for daily nitrogen loading in reactor of 0.3 to 0.8 TKN kg/sludge kg. Conclusions. The suggested technology provides the quality of treated water corresponding with the Vietnamese Standard A requirements. At the present, it is planned to proceed with the experiment on the base of Vietnamese semi-industrial plant for research and appraisal of the SBR reconstruction and modification method. Acknowledgements. The authors are grateful to AKVA Control company in Samara for granted biocarrier Mutag BioChip 25 and to Associate Professor Tran Van Quang and his students, Nguyen Ngoc Phuong and Truong Quoc Dai, of Environment Protect Research Center, Danang University for support of the experiment.

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.

A comparison of continuous flow and sequencing batch reactor plants concerning integrated operation of sewer systems and wastewater treatment plants

2006 ◽  
Vol 54 (11-12) ◽  
pp. 241-248 ◽  
Author(s):  
J. Simon ◽  
J. Wiese ◽  
H. Steinmetz
Keyword(s):  
Wastewater Treatment ◽  
Continuous Flow ◽  
Sequencing Batch Reactor ◽  
Wastewater Treatment Plants ◽  
Batch Reactor ◽  
Sewer Systems ◽  
Combined Sewer ◽  
Integrated Operation

Integrated operation strategies for combined sewer and WWTP are becoming more and more popular because of numerous benefits. One can find many examples in literature, but many of these studies deal with partly fictitious systems and/or were accomplished within the planning. Hence most of these studies do not have to deal with the restrictions given by already built constructions. The authors, who worked on several integrated projects, will discuss the requirements of SBR and CFR plants concerning an implementation of integrated operation.

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