Model Predicted N2O Production from Membrane-Aerated Biofilm Reactor is Greatly Affected by Biofilm Property Settings

Chemosphere ◽  
2021 ◽  
pp. 130861
Author(s):  
Xueming Chen ◽  
Pengfei Huo ◽  
Jinzhong Liu ◽  
Fuyi Li ◽  
Linyan Yang ◽  
...  
Keyword(s):  
Biofilm Reactor ◽  
N2o Production

scholarly journals Isotopic evidence for alteration of nitrous oxide emissions and producing pathways contribution under nitrifying conditions

2019 ◽  
Author(s):  
Guillaume Humbert ◽  
Mathieu Sébilo ◽  
Justine Fiat ◽  
Longqi Lang ◽  
Ahlem Filali ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Biofilm Reactor ◽  
Nitrite Reduction ◽  
Nitrous Oxide Emissions ◽  
Site Preference ◽  
N2o Emissions ◽  
Ammonium Oxidation ◽  
N2o Production ◽  
Oxidation Rates ◽  
Nitrifier Denitrification

Abstract. Nitrous oxide (N2O) emissions by a nitrifying biofilm reactor were investigated with N2O isotopocules. The site preference of N2O (15N-SP) indicated the contribution of producing and consuming pathways in response to changes in oxygenation level (from 0 to 21 % O2 in the gas mix), temperature (from 13.5 to 22.3 °C), and ammonium concentrations (from 6.2 to 62.1 mg N L−1). Nitrite reduction, either nitrifier-denitrification or heterotrophic denitrification, was the main N2O producing pathway under the tested conditions. Nitrite oxidation rates decreased as compared to ammonium oxidation rates at temperatures above 20 °C and sub-optimal oxygen levels, increasing N2O production by the nitrite reduction pathway. Below 20 °C, a difference in temperature sensitivity between hydroxylamine and ammonium oxidation rates is most likely responsible for an increase in the N2O production via the hydroxylamine oxidation pathway (nitrification). A negative correlation between the reaction kinetics and the apparent isotope fractionation was additionally shown from the variations of δ15N and δ18O values of N2O produced from ammonium.

scholarly journals Isotopic evidence for alteration of nitrous oxide emissions and producing pathways' contribution under nitrifying conditions

2020 ◽  
Vol 17 (4) ◽  
pp. 979-993
Author(s):  
Guillaume Humbert ◽  
Mathieu Sébilo ◽  
Justine Fiat ◽  
Longqi Lang ◽  
Ahlem Filali ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Biofilm Reactor ◽  
Nitrite Reduction ◽  
Nitrous Oxide Emissions ◽  
Site Preference ◽  
N2o Emissions ◽  
Ammonium Oxidation ◽  
N2o Production ◽  
Oxidation Rates ◽  
Nitrifier Denitrification

Abstract. Nitrous oxide (N2O) emissions from a nitrifying biofilm reactor were investigated with N2O isotopocules. The nitrogen isotopomer site preference of N2O (15N-SP) indicated the contribution of producing and consuming pathways in response to changes in oxygenation level (from 0 % to 21 % O2 in the gas mix), temperature (from 13.5 to 22.3 ∘C) and ammonium concentrations (from 6.2 to 62.1 mg N L−1). Nitrite reduction, either nitrifier denitrification or heterotrophic denitrification, was the main N2O-producing pathway under the tested conditions. Difference between oxidative and reductive rates of nitrite consumption was discussed in relation to NO2- concentrations and N2O emissions. Hence, nitrite oxidation rates seem to decrease as compared to ammonium oxidation rates at temperatures above 20 ∘C and under oxygen-depleted atmosphere, increasing N2O production by the nitrite reduction pathway. Below 20 ∘C, a difference in temperature sensitivity between hydroxylamine and ammonium oxidation rates is most likely responsible for an increase in N2O production via the hydroxylamine oxidation pathway (nitrification). A negative correlation between the reaction kinetics and the apparent isotope fractionation was additionally shown from the variations of δ15N and δ18O values of N2O produced from ammonium. The approach and results obtained here, for a nitrifying biofilm reactor under variable environmental conditions, should allow for application and extrapolation of N2O emissions from other systems such as lakes, soils and sediments.

scholarly journals New insights into nitrous oxide emissions in a single-stage CANON process coupled with denitrification: thermodynamics and nitrogen transformation

2020 ◽  
Author(s):  
Fang Fang ◽  
Kai Li ◽  
Jin-Song Guo ◽  
Han Wang ◽  
Ping Zhang ◽  
...  
Keyword(s):  
Carbon Sources ◽  
N2o Emission ◽  
Nitrogen Transformation ◽  
Biofilm Reactor ◽  
Nitrous Oxide Emissions ◽  
N2o Emissions ◽  
Ammonia Oxidizing Bacteria ◽  
N2o Production ◽  
Canon Process ◽  
Heterotrophic Denitrification

Abstract The dynamic characteristics of N2O emissions and nitrogen transformation in a sequencing batch biofilm reactor (SBBR) using the completely autotrophic nitrogen removal over nitrite (CANON) process coupled with denitrification were investigated via 15N isotope tracing and thermodynamic analysis. The results indicate that the Gibbs free energy (ΔG) values of N2O production by the nitrifier denitrification and heterotrophic denitrification reactions were greater than that of NH2OH oxidation, indicating that N2O was easier to produce via either nitrifier and heterotrophic denitrification than via NH2OH oxidation. Ammonia-oxidizing bacteria (AOB) denitrification exhibited a higher fs0 (the fraction of electron-donor electrons utilized for cell synthesis) than NH2OH oxidation. Therefore, AOB preferred the denitrification pathway because of its growth advantage when N2O was produced by the AOB. The N2O emissions by hydroxylamine oxidation, AOB denitrification and heterotrophic denitrification in the SBBRs using different C/N ratios account for 5.4–7.6%, 45.2–60.8% and 33.8–47.2% of the N2O produced, respectively. The total N2O emission with C/N ratios of 0, 0.67 and 1 was 228.04, 205.57 and 190.4 μg N2O-N·g−1VSS, respectively. The certain carbon sources aid in the reduction of N2O emissions in the process.

scholarly journals Dynamic modelling of nitrous oxide emissions from three Swedish sludge liquor treatment systems

2015 ◽  
Vol 73 (4) ◽  
pp. 798-806 ◽  
Author(s):  
E. Lindblom ◽  
M. Arnell ◽  
X. Flores-Alsina ◽  
F. Stenström ◽  
D. J. I. Gustavsson ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Batch Reactor ◽  
Dynamic Modelling ◽  
Biofilm Reactor ◽  
Nitrous Oxide Emissions ◽  
N2o Emissions ◽  
N2o Formation ◽  
N2o Production ◽  
Gas Phases ◽  
Transfer Equations

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.

Phosphorus Release Kinetics in Biofilm Reactors

1992 ◽  
Vol 26 (3-4) ◽  
pp. 567-576 ◽  
Author(s):  
F. A. Ruiz-Treviño ◽  
S. González-Martínez ◽  
C. Doria-Serrano ◽  
M. Hernández-Esparza
Keyword(s):  
Phosphorus Removal ◽  
Release Kinetics ◽  
Phosphorus Release ◽  
Organic Substrate ◽  
Biofilm Reactor ◽  
Substrate Uptake ◽  
Biofilm Reactors ◽  
Initial Substrate ◽  
Linear Behaviour ◽  
Substrate Concentrations

This paper presents the kinetic analysis, using Generalized Power-Law equations to describe the results of an experimental investigation conducted on a batch submerged biofilm reactor for phosphorus removal under an anaerobic/aerobic cycle. The observed rates and amounts of phosphorus release and organic substrate uptake in the anaerobic phase leads to a kinetic model in which these two variables are dependent on each other with a non-linear behaviour and reach equilibrium values in both cases, at different times and are function of rate constants ratio. The model has a good fit with experimental data except for C uptake at anaerobic contact times longer than four hours, where other kinetics are implied. Kinetic parameters were obtained with different initial substrate concentrations, anaerobic contact cycles, and type of substrates.

Anaerobic Thermophilic (55°C) Treatment of TMP Whitewater in Reactors Based on Biomass Attachment and Entrapment

1999 ◽  
Vol 40 (11-12) ◽  
pp. 67-75 ◽  
Author(s):  
Sigrun J. Jahren ◽  
Jukka A. Rintala ◽  
Hallvard Ødegaard
Keyword(s):  
Granular Sludge ◽  
Biofilm Reactor ◽  
Upflow Anaerobic Sludge Blanket ◽  
Hybrid Reactor ◽  
Anaerobic Sludge ◽  
Loading Rates ◽  
Anaerobic Reactors ◽  
Multi Stage ◽  
Degradation Rates ◽  
Thermomechanical Pulping

Thermomechanical pulping (TMP) whitewater was treated in thermophilic (55°C) anaerobic laboratory-scale reactors using three different reactor configurations. In all reactors up to 70% COD removals were achieved. The anaerobic hybrid reactor, composed of an upflow anaerobic sludge blanket (UASB) and a filter, gave degradation rates up to 10 kg COD/m3d at loading rates of 15 kg COD/m3d and hydraulic retention time (HRT) of 3.1 hours. The anaerobic multi-stage reactor, consisting of three compartments, each packed with granular sludge and carrier elements, gave degradation rates up to 9 kg COD/m3d at loading rates of 15-16 kg COD/m3d, and HRT down to 2.6 hours. Clogging and short circuiting eventually became a problem in the multi-stage reactor, probably caused by too high packing of the carriers. The anaerobic moving bed biofilm reactor performed similar to the other reactors at loading rates below 1.4 kg COD/m3d, which was the highest loading rate applied. The use of carriers in the anaerobic reactors allowed short HRT with good treatment efficiencies for TMP whitewater.

Retention and expression of recombinant plasmids in suspended and biofilm-bound bacteria degrading trichloroethene (TCE)

1997 ◽  
Vol 36 (10) ◽  
pp. 1-8 ◽  
Author(s):  
James D. Bryers ◽  
Robert R. Sharp
Keyword(s):  
Biofilm Reactor ◽  
Bacterial Biofilm ◽  
Laboratory Evaluation ◽  
Recombinant Bacteria ◽  
Suitable Host ◽  
Term Operation ◽  
Open Environment ◽  
Recombinant Microorganisms ◽  
Extracellular Polymer

Exposure of plasmid recombinant microorganisms to an open environment, either inadvertently or intentionally, requires research into those fundamental processes that govern plasmid retention, transfer and expression. In the open environment, a majority of the microbial activity occurs associated with an interface, within thin biological layers consisting of cells and their insoluble extracellular polymer, layers known as biofilms. Current toxic wastewater or wastegas treatment reactors exploit bacterial biofilm systems for certain system operating advantages. Using recombinant bacteria within a biofilm reactor to degrade xenobiotic wastes requires finding a suitable host to harbor and express the desired plasmid phenotype. Suitable host characteristics include: the ability to produce copious amounts of biofilm, resistance to waste-related injury and toxicity, and the ability to retain and express the desired plasmid during long term operation. This paper reports on a laboratory evaluation of factors governing plasmid retention and the expression of trichloroethene (TCE) degradative capacity in both suspended and biofilm cultures.

Use of a dynamic gassing-out method for activity and oxygen diffusion coefficient estimation in biofilms

1998 ◽  
Vol 37 (4-5) ◽  
pp. 171-175
Author(s):  
Artem Khlebnikov ◽  
Falilou Samb ◽  
Paul Péringer
Keyword(s):  
Diffusion Coefficient ◽  
Oxygen Uptake ◽  
Oxygen Diffusion ◽  
Fixed Bed ◽  
Biofilm Reactor ◽  
Strictly Aerobic ◽  
Comamonas Testosteroni ◽  
Respiration Activity ◽  
Oxygen Diffusion Coefficient ◽  
Biofilm Development

p-toluenesulphonic acid degradation by Comamonas testosteroni T-2 in multi-species biofilms was studied in a fixed bed biofilm reactor. The polypropylene static mixer elements (Sulzer Chemtech Ltd., Switzerland) were used as a support matrix for biofilm formation. Biofilm respiration was estimated using the dynamic gassing-out oxygen uptake method. A strong relation between oxygen uptake and reactor degradation efficiency was observed, because p-toluenesulphonate degradation is a strictly aerobic process. This technique also allowed us to estimate the thickness of the active layer in the studied system. The mean active thickness was in order of 200 μm, which is close to maximum oxygen penetration depth in biofilms. A transient mathematical model was established to evaluate oxygen diffusitivity in non-steady-state biofilms. Based on the DO concentration profiles, the oxygen diffusion coefficient and the maximum respiration activity were calculated. The oxygen diffusion coefficient obtained (2 10−10-1.2 10−9 m2 s−1) is in good agreement with published values. The DO diffusion coefficient varied with biofilm development. This may be, most likely, due to the biofilm density changes during the experiments. The knowledge of diffusivity changes in biofilms is particularly important for removal capacity estimation and appropriate reactor design.

Carbon tetrachloride biodegradation in a fixed-biofilm reactor and its kinetic study

1998 ◽  
Vol 38 (8-9) ◽  
pp. 155-162 ◽  
Author(s):  
G. Jin ◽  
A. J. Englande
Keyword(s):  
Carbon Tetrachloride ◽  
Continuous Flow ◽  
Model Comparison ◽  
Biofilm Reactor ◽  
Pseudomonas Cepacia ◽  
Initial Concentration ◽  
Biphasic Model ◽  
Providencia Stuartii ◽  
Kinetics Of ◽  
Fixed Biofilm

Kinetics of Carbon Tetrachloride biodegradation are evaluated in a continuous-flow fixed-biofilm reactor with controlled initial redox potential. The column was seeded with a mixed culture of indigenous microorganisms Pseudomonas cepacia and Providencia stuartii. The fixed biofilm reactor exhibited 98%–99.9% biodegradation of CT introduced into the reactor at an initial concentration of about 200 μg/l for retention times of 1 to 4 days respectively. Four models were employed to evaluate the kinetics of CT biodegradation. These included: Eckenfelder (1989), Arvin (1991), Bouwer and McCarty (1985) and a biphasic model. Comparison of calculated results with observed results between these models agreed very closely to each other (0.968 < R2 < 0.999). Predicted performance was best described by the model of Bouwer and McCarty (1985). However, the biphasic and Eckenfelder models provided excellent correlations and were much simpler to apply. The biphasic model yielded very good correlations of the data for all detention times evaluated; whereas, the Eckenfelder model effected comparable results only at the longer retention times studied.

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