Full-scale comparison of N2O emissions from SBR N/DN operation versus one-stage deammonification MBBR treating reject water – and optimization with pH set-point

2019 ◽  
Vol 79 (8) ◽  
pp. 1616-1625 ◽  
Author(s):  
L. Kanders ◽  
J-J. Yang ◽  
C. Baresel ◽  
J. Zambrano

Abstract To be able to fulfill the Paris agreement regarding anthropogenic greenhouse gases, all potential emissions must be mitigated. Wastewater treatment plants should aim to eliminate emissions of the most potent greenhouse gas, nitrous oxide (N2O). In this study, these emissions were measured at a full-scale reject water treatment tank during two different operation modes: nitrification/denitrification (N/DN) operating as a sequencing batch reactor (SBR), and deammonification (nitritation/anammox) as a moving bed biofilm reactor (MBBR). The treatment process emitted significantly less nitrous oxide in deammonification mode 0.14–0.7%, compared to 10% of total nitrogen in N/DN mode. The decrease can be linked to the changed feeding strategy, the lower concentrations of nitrite, a lower load of ammonia oxidized, a shorter aeration time, the absence of non-optimized ethanol dosage or periodic lack of oxygen as well as the introduction of biofilm. Further, evaluation was done how the operational pH set point influenced the emissions in deammonification mode. Lower concentrations of nitrous oxide were measured in water phase at higher pH (7.5–7.6) than at lower pH (6.6–7.1). This is believed to be mainly because of the lower aeration ratio and increased complete denitrification at the higher pH set point.

2013 ◽  
Vol 47 (14) ◽  
pp. 7795-7803 ◽  
Author(s):  
Bing-Jie Ni ◽  
Liu Ye ◽  
Yingyu Law ◽  
Craig Byers ◽  
Zhiguo Yuan

2013 ◽  
Vol 69 (1) ◽  
pp. 84-91 ◽  
Author(s):  
F. Stenström ◽  
K. Tjus ◽  
J. la Cour Jansen

Nitrous oxide (N2O) is a potent greenhouse gas and of special concern in wastewater treatment. It is formed in biological wastewater treatment under both aerobic and anaerobic conditions. A major reason for high N2O emissions is low oxygen concentration during nitrification. In this full-scale study of N2O emissions from a sequencing batch reactor for treating digester supernatant, the oxygen concentration was reduced stepwise to investigate how N2O emissions were influenced. N2O concentrations were measured online in water and off-gas. A distinct relationship was found between low oxygen concentration and high N2O emissions. N2O was formed in water during both nitrification and denitrification. Decreased oxygen concentration during nitrification led to increased nitrite concentration, which in turn led to increased N2O concentration in the subsequent denitrification phase. When the nitrification resumed, accumulated N2O was stripped off to the atmosphere. Very high concentrations of N2O, over 56,000 ppmv, were measured in the off-gas. Furthermore, the maximum amount of N2O emitted during one cycle corresponded to 107.6% of the total nitrogen load (21.9% of total nitrogen present in the bulk liquid at the beginning of the cycle). This is among the highest emission levels ever measured from a full-scale municipal plant for digester supernatant.


2015 ◽  
Vol 73 (4) ◽  
pp. 798-806 ◽  
Author(s):  
E. Lindblom ◽  
M. Arnell ◽  
X. Flores-Alsina ◽  
F. Stenström ◽  
D. J. I. Gustavsson ◽  
...  

The objective of this paper is to model the dynamics and validate the results of nitrous oxide (N2O) emissions from three Swedish nitrifying/denitrifying, nitritation and anammox systems treating real anaerobic digester sludge liquor. The Activated Sludge Model No. 1 is extended to describe N2O production by both heterotrophic and autotrophic denitrification. In addition, mass transfer equations are implemented to characterize the dynamics of N2O in the water and the gas phases. The biochemical model is simulated and validated for two hydraulic patterns: (1) a sequencing batch reactor; and (2) a moving-bed biofilm reactor. Results show that the calibrated model is partly capable of reproducing the behaviour of N2O as well as the nitritation/nitrification/denitrification dynamics. However, the results emphasize that additional work is required before N2O emissions from sludge liquor treatment plants can be generally predicted with high certainty by simulations. Continued efforts should focus on determining the switching conditions for different N2O formation pathways and, if full-scale data are used, more detailed modelling of the measurement devices might improve the conclusions that can be drawn.


2009 ◽  
Vol 60 (12) ◽  
pp. 3211-3217 ◽  
Author(s):  
M. J. Kampschreur ◽  
R. Poldermans ◽  
R. Kleerebezem ◽  
W. R. L. van der Star ◽  
R. Haarhuis ◽  
...  

At a full-scale single-stage nitritation-anammox reactor, off-gas measurement for nitric oxide (NO) and nitrous oxide (N2O) was performed. NO and N2O are environmental hazards, imposing the risk of improving water quality at the cost of deteriorating air quality. The emission of NO during normal operation of a single-stage nitritation-anammox process was 0.005% of the nitrogen load while the N2O emission was 1.2% of the nitrogen load to the reactor, which is in the same range as reported emission from other full-scale wastewater treatment plants. The emission of both compounds was strongly coupled. The concentration of NO and N2O in the off-gas of the single-stage nitritation-anammox reactor was rather dynamic and clearly responded to operational variations. This exemplifies the need for time-dependent measurement of NO and N2O emission from bioreactors for reliable emission estimates. Nitrite accumulation clearly resulted in increased NO and N2O concentrations in the off-gas, yielding higher emission levels. Oxygen limitation resulted in a decrease in NO and N2O emission, which was unexpected as oxygen limitation is generally assumed to cause increased emissions in nitrogen converting systems. Higher aeration flow dramatically increased the NO emission load and also seemed to increase the N2O emission, which stresses the importance of efficient aeration control to limit NO and N2O emissions.


2016 ◽  
Vol 74 (11) ◽  
pp. 2541-2550 ◽  
Author(s):  
Linda Kanders ◽  
Daniel Ling ◽  
Emma Nehrenheim

In recent years, the anammox process has emerged as a useful method for robust and efficient nitrogen removal in wastewater treatment plants (WWTPs). This paper evaluates a one-stage deammonification (nitritation and anammox) start-up using carrier material without using anammox inoculum. A continuous laboratory-scale process was followed by full-scale operation with reject water from the digesters at Bekkelaget WWTP in Oslo, Norway. A third laboratory reactor was run in operational mode to verify the suitability of reject water from thermophilic digestion for the deammonification process. The two start-ups presented were run with indigenous bacterial populations, intermittent aeration and dilution, to favour growth of the anammox bacterial branches. Evaluation was done by chemical and fluorescence in situ hybridization analyses. The results demonstrate that anammox culture can be set up in a one-stage process only using indigenous anammox bacteria and that a full-scale start-up process can be completed in less than 120 days.


2016 ◽  
Vol 18 (3) ◽  
pp. 406-416 ◽  
Author(s):  
Khalid Muzamil Gani ◽  
Ankur Rajpal ◽  
Absar Ahmad Kazmi

The contamination level of four phthalates in untreated and treated wastewater of fifteen wastewater treatment plants (WWTPs) and their fate in a full scale sequencing batch reactor (SBR) based WWTP was evaluated in this study.


Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 1013 ◽  
Author(s):  
Takahiro Yamashita ◽  
Makoto Shiraishi ◽  
Hiroshi Yokoyama ◽  
Akifumi Ogino ◽  
Ryoko Yamamoto-Ikemoto ◽  
...  

Nitrous oxide (N2O) is a potent greenhouse gas that is emitted from wastewater treatment plants. To reduce emissions of N2O from swine wastewater treatment plants, we constructed an experimental aerobic bioreactor packed with carbon fibres (ca. 1 m3 bioreactor) as an alternative to conventional activated sludge treatment. The N2O emission factor for the aerobic bioreactor packed with carbon fibres (CF) was 0.002 g N2O-N/g TN-load and the value for the typical activated sludge (AS) reactor was 0.013 g N2O-N/g TN-load. The CF treatment method achieved more than 80% reduction of N2O emissions, compared with the AS treatment method. The experimental introduction of a CF carrier into an actual wastewater treatment plant also resulted in a large reduction in N2O generation. Specifically, the N2O emission factors decreased from 0.040 to 0.005 g N2O-N/g TN-load following application of the carrier. This shows that it is possible to reduce N2O generation by more than 80% by using a CF carrier during the operation of an actual wastewater treatment plant. Some bacteria from the phylum Chloroflexi, which are capable of reducing N2O emissions, were detected at a higher frequency in the biofilm on the CF carrier than in the biofilm formed on the AS reactor.


1996 ◽  
Vol 34 (1-2) ◽  
pp. 277-284 ◽  
Author(s):  
Hiroki Itokawa ◽  
Keisuke Hanaki ◽  
Tomonori Matsuo

Nitrous oxide (N2O) emissions from nitrification-denitrification processes in a full-scale night soil treatment plant were measured, and patterns and control of the N2O production were investigated. Estimated N2O emissions ranged from 4.4 to 1,190 gN/(m3 of influent), corresponding to a conversion ratio of influent nitrogen to N2O-N of 0.24-55%. N2O was produced in the intermittent aeration tank (IAT) where nitrification and denitrification were carried out alternately. The produced N2O was either stripped out to the off-gas or remained in the effluent in dissolved form. The former accounted for more than 99.5% of the total emissions. The latter flowed into the following anoxic tank, where 60-98% of N2O was reduced. A significant difference in the extent of N2O supersaturation in mixed liquor of IAT was observed between the cases of high and low N2O emissions. In IAT, N2O tended to be produced discretely either in aerobic or in anoxic phases. It seemed that the completeness of nitrification and denitrification in IAT, indicated from a mass balance between NH4-N and NO3-N and from NO2-N accumulation in mixed liquor of IAT, was one of the important factors affecting the N2O production. This completeness was decided by the time ratio of aerobic and anoxic phases. External addition of methanol to IAT seemed to reduce N2O emissions.


2008 ◽  
Vol 42 (3) ◽  
pp. 812-826 ◽  
Author(s):  
Marlies J. Kampschreur ◽  
Wouter R.L. van der Star ◽  
Hubert A. Wielders ◽  
Jan Willem Mulder ◽  
Mike S.M. Jetten ◽  
...  

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