Factors affecting N2O emissions from wastewater treatment plants: Comparison
Please note this is a comparison between Version 1 by Liana Kemmu and Version 3 by Catherine Yang.

Nitrous oxide (N2O) is a greenhouse gas contributing to ozone layer depletion and climate

change. Wastewater treatment plants (WWTPs) geconeratribute significant amounts of grely to the global anthropogenic

N2O emissionhouse gs. The main factors affecting N2O emissions asre thes, including carb dissolved oxygen concentration

(DO), dthe nioxide, methane and nitrous oxide. Nitrous oxitrite accumulation, the rapidly changing process conditions, the substrate composition

ande (COD/N2O) ratis an important greenho, the pH, and the temperature. Low DO in the nitrification process results in higher

N2O emissiounse gas with a global warming , whereas high aeration rate in the nitration/anammox process results in higher N2O

protential (GWP) 273 times that of carbon dioxide (Cduction. High DO in the denitrification inhibits the N2O2), reducontributitase synthesis/activity, leading to

N2O accumulatiozone layer deplen. High nitrite accumulation in both the nitrification and climate change. Therefore, even denitrification processesma

ll eamounts ofds to high N2O emissions. can sigTransient DO changes and rapid shifts in pH result in high N2O

production. Ammonificantly contributea shock loads leads to incomplete nitrification, resulting in NO2- accumulatoion

and N2O formatiotal greenhouse gases (GHG) emissions. Thus, in. Limiting the biodegradable substrate hinders complete denitrification, leading

to can behigh N2O produconcluded that the minimization of tion. A COD/N ratio above 4 results in 20–30% of the nitrogen load being

N2O emissions. aMaximum N2O productiond the iat low pH (pH = 6) was observed during nitrification/

denitrification of the factors controlling thand at high pH (pH = 8) during partial nitrification. High temperature enhances

the demissions constitute a greatnitrification kinetics but produces more N2O challengemissions.

  • N2O production pathways
  • hydroxylamine oxidation
  • nitrifier denitrification
  • heterotrophic denitrification
  • influence of DO
  • COD/N
  • pH and temperature
  • N2O sampling
  • N2O measurements
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References

  1. Gupta, D.; Singh, S.K. Greenhouse Gas Emissions from Wastewater Treatment Plants: A Case Study of Noida. J. Water Sustain. 2012, 2, 131–139.Liana Kemmou; Elisavet Amanatidou; Factors Affecting Nitrous Oxide Emissions from Activated Sludge Wastewater Treatment Plants—A Review. Resour. 2023, 12, 114.
  2. IPCC. Summary for Policymakers. In Climate Change 2023: Synthesis Report. A Report of the Intergovernmental Panel on Climate Change; Contribution of Working Groups I, II and III to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change; Core Writing Team, Lee, H., Romero, J., Eds.; IPCC: Geneva, Switzerland, 2023; pp. 1–34.
  3. USEPA. Inventory of U.S. Greenhouse Gas Emissions and Sinks; USEPA: Washington, DC, USA, 2021.
  4. Montzka, S.A.; Reimann, S. Ozone depleting Substances (ODSs) and Related Chemicals (Chapter 1). In Scientific Assessment of Ozone Depletion: 2010; Global Ozone Research and Monitoring Project, Report No. 52; World Meteorological Organization: Geneva, Switzerland, 2011; p. 516.
  5. Wunderlin, P.; Mohn, J.; Joss, A.; Emmenegger, L.; Siegrist, H. Mechanisms of N2O production in biological wastewater treatment under nitrifying and denitrifying conditions. Water Res. 2012, 46, 1027–1037.
  6. Law, Y.; Ye, L.; Pan, Y.; Yuan, Z. Nitrous oxide emissions from wastewater treatment processes. Philos. Trans. R. Soc. 2012, 367, 1265–1277.
  7. Wang, C.; Amon, B.; Schylz, K.; Mehdi, B. Factors That Influence Nitrous Oxide Emissions from Agricultural Soils as Well as Their Representation in Simulation Models: A Review. Agronomy 2021, 11, 770.
  8. Rout, P.; Das, R.; Das, S.N. Rise in nitrous oxide levels due to fossil fuel combustion in urban atmosphere. J. Sci. Ind. Res. 2005, 64, 46–52.
  9. Domingo-Felez, C.; Smets, B.F. Regulation of key N2O production mechanisms during biological water treatment. Curr. Opin. Biotechnol. 2019, 57, 119–126.
  10. Kampschreur, M.J.; Temmink, H.; Kleerebezem, R.; Jetten, M.S.M.; van Loosdrecht, M.C.M. Nitrous oxide emission during wastewater treatment. Water Res. 2009, 43, 4093–4103.
  11. Daelman, M. Emissions of Methane and Nitrous Oxide from Full-Scale Municipal Wastewater Treatment Plants. PhD Thesis, Technical University of Delft, Delft, The Netherlands, October 2014.
  12. Gruber, W.; Villez, K.; Kipf, M.; Wunderlin, P.; Siegrist, H.; Vogt, L.; Joss, A. N2O emission in full-scale wastewater treatment: Proposing a refined monitoring strategy. Sci. Total Environ. 2020, 699, 134–157.
  13. Yao, H.; Gao, X.; Guo, J.; Wang, H.; Zhang, L.; Fan, L.; Jia, F.; Guo, J.; Peng, Y. Contribution of nitrous oxide to the carbon footprint of full-scale wastewater treatment plants and mitigation strategies—A critical review. Environ. Pollut. 2022, 314, 120295.
  14. Płuciennik-Koropczuk, E.; Myszograj, S. Significance of wastewater treatment to nitrous oxide emission. Civ. Environ. Eng. Rep. 2021, 31, 237–248.
  15. Chen, Y.C.; Kuo, J. Potential of greenhouse gas emissions from sewage sludge management: A case study of Taiwan. J. Clean. Prod. 2016, 129, 196–201.
  16. Frison, N.; Chiumenti, A.; Katsou, E.; Malamis, S.; Bolzonella, D.; Fatone, F. Mitigating off-gas emissions in the biological nitrogen removal via nitrite process treating anaerobic effluents. J. Clean. Prod. 2015, 93, 126–133.
  17. Colliver, B.B.; Stephenson, T. Production of nitrogen oxide and dinitrogen oxide by autotrophic nitrifiers. Biotechnol. Adv. 2000, 18, 219–232.
  18. Ahn, J.H.; Kim, S.; Park, H.; Katehis, D.; Pagilla, K.; Chandran, K. Spatial and Temporal Variability in Atmospheric Nitrous Oxide Generation and Emission from Full-Scale Biological Nitrogen Removal and Non-BNR Processes. Water Environ. Res. 2010, 82, 2362–2372.
  19. Malamis, S.; Katsou, E.; Fatone, F. Integration of energy efficient processes in carbon and nutrient removal from sewage. In Sewage Treatment Plants: Economic Evaluation of Innovative Technologies for Energy Efficiency; Stamatelatou, K., Tsagarakis, K., Eds.; IWA Publishing: London, UK, 2015; pp. 71–94.
  20. Baresel, C.; Andersson, S.; Yang, J.; Andersen, M.H. Comparison of nitrous oxide (N2O) emissions calculations at a Swedish wastewater treatment plant based on water concentrations versus off-gas concentrations. Adv. Clim. Chang. Res. 2016, 7, 185–191.
  21. Mannina, G.; Ekama, G.; Caniani, D.; Cosenza, A.; Esposito, G.; Gori, R.; Garrido-Baserba, M.; Rosso, D.; Olsson, G. Greenhouse gases from wastewater treatment—A review of modelling tools. Sci. Total Environ. 2016, 551–552, 254–270.
  22. Su, Q.; Domingo-Felez, C.; Zhang, Z.; Blum, J.; Jensen, M.M.; Smets, B.F. The effect of pH on N2O production in intermittently-fed nitritation reactors. Water Res. 2019, 156, 223–231.
  23. Vieira, A.; Galinha, C.F.; Oehmen, A.; Carvalho, G. The link between nitrous oxide emissions, microbial community profile and function from three full-scale WWTPs. Sci. Total Environ. 2019, 651, 2460–2472.
  24. Vasilaki, V.; Conca, V.; Frison, N.; Eusebi, A.L.; Fatone, F.; Katsou, E. A knowledge discovery framework to predict the N2O emissions in the wastewater sector. Water Res. 2020, 178, 115799.
  25. Valkova, T.; Parravicini, V.; Saracevic, E.; Tauber, J.; Svardal, K.; Krampe, J. A method to estimate the direct nitrous oxide emissions of municipal wastewater treatment plants based on the degree of nitrogen removal. J. Environ. Manag. 2021, 279, 111563.
  26. Bae, W.B.; Park, Y.; Chandran, K.; Shin, J.; Kang, S.B.; Wang, J.; Kim, Y.M. Temporal triggers of N2O emissions during cyclical and seasonal variations of a full-scale sequencing batch reactor treating municipal wastewater. Sci. Total Environ. 2021, 797, 149093.
  27. Law, Y.; Lant, P.; Yuan, Z. The Confounding Effect of Nitrite on N2O Production by an Enriched Ammonia-Oxidizing Culture. Environ. Sci. Technol. 2013, 47, 7186–7194.
  28. Caranto, J.D.; Lancaster, K.M. Nitric oxide is an obligate bacterial nitrification intermediate produced by hydroxylamine oxidoreductase. Proc. Natl. Acad. Sci. USA 2017, 114, 8217–8222.
  29. Reino, C.; van Loosdrecht, M.C.M.; Carrera, J.; Perez, J. Effect of temperature on N2O emissions from a highly enriched nitrifying granular sludge performing partial nitritation of a low strength wastewater. Chemosphere 2017, 185, 336–343.
  30. Chen, S.; Harb, M.; Sinha, P.; Smith, A.L. Emerging investigators series: Revisiting greenhouse gas mitigation from conventional activated sludge and anaerobic-based wastewater treatment systems. Environ Sci. Water Res. Technol. 2018, 4, 17–39.
  31. Massara, T.M.; Solís, B.; Guisasola, A.; Katsou, E.; Baeza, J.A. Development of an ASM2d-N2O model to describe nitrous oxide emissions in municipal WWTPs under dynamic conditions. Chem. Eng. J. 2018, 335, 85–196.
  32. Guo, G.; Wang, Y.; Hao, T.; Wu, D.; Chen, G.H. Enzymatic nitrous oxide emissions from wastewater treatment. Front. Environ. Sci. Eng. 2018, 12, 10.
  33. Chai, H.; Deng, S.; Zhou, X.; Su, C.; Xiang, Y.; Yang, Y.; Shao, Z.; Gu, L.; Xu, X.; Ji, F.; et al. Nitrous oxide emission mitigation during low–carbon source wastewater treatment: Effect of external carbon source supply strategy. Environ. Sci. Pollut. Res. 2019, 26, 23095–23107.
  34. Wan, X.; Baeten, J.E.; Volcke, E.I.P. Effect of operating conditions on N2O emissions from one-stage partial nitritation-anammox reactors. Biochem. Eng. J. 2019, 143, 24–33.
  35. Anderson, J.H. The metabolism of hydroxylamine to nitrite by Nitrosomonas. Biochem. J. 1964, 91, 8–17.
  36. Ritchie, G.A.F.; Nicholas, D.J.D. Identification of the sources of nitrous oxide produced by oxidative and reductive processes in Nitrosomonas europaea. Biochem. J. 1972, 126, 1181–1191.
  37. Hooper, A.B.; Terry, K.R. Hydroxylamine oxidoreductase of Nitrosomonas, production of nitric oxide from hydroxylamine. Biochim. Biophys. Acta 1979, 571, 12–20.
  38. Igarashi, N.; Moriyama, H.; Fujiwara, T.; Fukumori, Y.; Tanaka, N. The 2.8 A structure of hydroxylamine oxidoreductase from a nitrifying chemoautotrophic bacterium, Nitrosomonas europaea. Nat. Struct. Mol. Biol. 1997, 4, 276–284.
  39. Poughon, L.; Dussap, C.G.; Gros, J.B. Energy model and metabolic flux analysis for autotrophic nitrifiers. Biotechnol. Bioeng. 2001, 72, 416–433.
  40. Arp, D.J.; Stein, L.Y. Metabolism of inorganic N compounds by ammonia-oxidizing bacteria. Crit. Rev. Biochem. Mol. Biol. 2003, 38, 471–495.
  41. Stein, L.Y. Surveying N2O-producing pathways in bacteria. Methods Enzymol. 2010, 486, 131–152.
  42. Hynes, R.K.; Knowles, R. Production of nitrous oxide by Nitrosomonas europaea: Effects of acetylene, pH, and oxygen. Can. J. Microbiol. 1984, 30, 1397–1404.
  43. Zheng, H.; Hanaki, K.; Matsuo, T. Production of nitrous oxide gas during nitrification of wastewater. Water Sci. Technol. 1994, 30, 133–141.
  44. Kester, R.A.; De Boer, W.; Laanbroek, H.J. Production of NO and N2O by pure cultures of nitrifying and denitrifying bacteria during changes in aeration. Appl. Environ. Microbiol. 1997, 63, 3872–3877.
  45. Desloover, J.; De Clippeleir, H.; Boeckx, P.; Du Laing, G.; Colsen, J.; Verstraete, W.; Vlaeminck, S.E. Floc-based sequential partial nitritation and anammox at full scale with contrasting N2O emissions. Water Res. 2011, 45, 2811–2821.
  46. Aboobakar, A.; Cartmell, E.; Stephenson, T.; Jones, M.; Vale, P.; Dotro, G. Nitrous oxide emissions and dissolved oxygen profiling in a full-scale nitrifying activated sludge treatment plant. Water Res. 2013, 47, 524–534.
  47. Peng, L.; Ni, B.J.; Ye, L.; Yuan, Z. The combined effect of dissolved oxygen and nitrite on N2O production by ammonia oxidizing bacteria in an enriched nitrifying sludge. Water Res. 2015, 73, 29–36.
  48. Santín, I.; Barbu, M.; Pedret, C.; Vilanova, R. Control strategies for nitrous oxide emissions reduction on wastewater treatment plants operation. Water Res. 2017, 125, 466–477.
  49. Goreau, T.J.; Kaplan, W.A.; Wofsy, S.C.; McElroy, M.B.; Valois, F.W.; Watson, S.W. Production of NO2− and N2O by nitrifying bacteria at reduced concentrations of oxygen. Appl. Environ. Microbiol. 1980, 40, 526–532.
  50. Xie, W.M.; Ni, B.J.; Li, W.W.; Sheng, G.P.; Yu, H.Q.; Song, J. Formation and quantification of soluble microbial products and N2O production by ammonia-oxidizing bacteria (AOB)-enriched activated sludge. Chem. Eng. Sci. 2012, 71, 67–74.
  51. Li, P.; Wang, S.; Peng, Y.; Liu, Y.; He, J. The synergistic effects of dissolved oxygen and pH on N2O production in biological domestic wastewater treatment under nitrifying conditions. Environ. Technol. 2015, 36, 1623–1631.
  52. Lv, Y.; Ju, K.; Sun, T.; Wang, L.; Miao, R.; Liu, T.; Wang, X. Effect of the dissolved oxygen concentration on the N2O emission from an autotrophic partial nitritation reactor treating high ammonium wastewater. Int. Biodeterior. Biodegrad. 2016, 114, 209–215.
  53. Peng, L.; Ni, B.J.; Erler, D.; Ye, L.; Yuan, Z. The effect of dissolved oxygen on N2O production by ammonia-oxidizing bacteria in an enriched nitrifying sludge. Water Res. 2014, 66, 12–21.
  54. Chandran, K.; Stein, L.Y.; Klotz, M.G.; Van Loosdrecht, M.C.M. Nitrous oxide production by lithotrophic ammonia-oxidizing bacteria and implications for engineered nitrogen-removal systems. Biochem. Soc. Trans. 2011, 39, 1832–1837.
  55. Castro-Barros, C.M.; Daelman, M.; Mampaey, K.; Van Loosdrecht, M.C.M.; Volcke, E. Effect of aeration regime on N2O emission from partial nitritation-anammox in a full-scale granular sludge reactor. Water Res. 2015, 68, 793–803.
  56. Rathnayake, R.M.; Oshiki, M.; Ishii, S.; Segawa, T.; Satoh, H.; Okabe, S. Effects of dissolved oxygen and pH on nitrous oxide production rates in autotrophic partial nitrification granules. Bioresour. Technol. 2015, 197, 15–22.
  57. Metcalf & Eddy Inc. Wastewater Engineering: Treatment and Resource Recovery, 5th ed.; Tchobanoglous, G., Burton, F.L., Stensel, H.D., Eds.; McGraw-Hill Education: New York, NY, USA, 2014.
  58. Shiskowski, D.M.; Mavinic, D.S. The influence of nitrite and pH (nitrous acid) on aerobic-phase, autotrophic N2O generation in a wastewater treatment bioreactor. J. Environ. Eng. Sci. 2006, 5, 273–283.
  59. Massara, T.M.; Malamis, S.; Guisasola, A.; Baeza, J.A.; Noutsopoulos, C.; Katsou, E. A review on nitrous oxide (N2O) emissions during biological nutrient removal from municipal wastewater and sludge reject water. Sci. Total Environ. 2017, 596–597, 106–123.
  60. Ahn, J.H.; Kwan, T.; Chandran, K. A comparison of partial and full nitrification processes applied for treating high-strength nitrogen wastewaters: Microbial ecology through nitrous oxide production. Environ. Sci. Technol. 2011, 45, 2734–2740.
  61. Peng, L.; Carvajal-Arroyo, J.M.; Seuntjens, D.; Prat, D.; Colica, G.; Pintucci, C.; Vlaeminck, S.E. Smart operation of nitritation/denitritation virtually abolishes nitrous oxide emission during treatment of co-digested pig slurry centrate. Water Res. 2017, 127, 1–10.
  62. Beaumont, H.J.E.; Lens, S.I.; Reijnders, W.N.M.; Westerhoff, H.V.; Van Spanning, R.J.M. Expression of nitrite reductase in Nitrosomonas europaea involves NsrR, a novel nitrite-sensitive transcription repressor. Mol. Microbiol. 2004, 54, 148–158.
  63. Schulthess, R.V.; Kuhni, M.; Gujer, W. Release of Nitric and Nitrous Oxides from Denitrifying Activated Sludge. Water Res. 1995, 29, 215–226.
  64. Alinsafi, A.; Adouani, N.; Béline, F.; Lendormi, T.; Limousy, L.; Sire, O. Nitrite effect on nitrous oxide emission from denitrifying activated sludge. Process Biochem. 2008, 43, 683–689.
  65. Zhou, Y.; Pijuan, M.; Zeng, R.J.; Yuan, Z. Free nitrous acid inhibition on nitrous oxide reduction by a denitrifying-enhanced biological phosphorus removal sludge. Environ. Sci. Technol. 2008, 42, 8260–8265.
  66. Zhou, Y.; Lim, M.; Harjono, S.; Ng, W.J. Nitrous oxide emission by denitrifying phosphorus removal culture using polyhydroxyalkanoates as carbon source. J. Environ. Sci. 2012, 24, 1616–1623.
  67. Kinh, C.T.; Ahn, J.; Suenaga, T.; Sittivorakulpong, N.; Noophan, P.; Hori, T.; Riya, S.; Hosomi, M.; Terada, A. Free nitrous acid and pH determine the predominant ammonia-oxidizing bacteria and amount of N2O in a partial nitrifying reactor. Appl. Microbiol. Biotechnol. 2017, 101, 1673–1683.
  68. Pan, Y.; Ni, B.J.; Bond, P.L.; Ye, L.; Yuan, Z. Electron competition among nitrogen oxides reduction during methanol-utilizing denitrification in wastewater treatment. Water Res. 2013, 47, 3273–3281.
  69. Burgess, J.E.; Colliver, B.B.; Stuetz, R.M.; Stephenson, T. Dinitrogen oxide production by a mixed culture of nitrifying bacteria during ammonia shock loading and aeration failure. J. Ind. Microbiol. Biotechnol. 2002, 29, 309–313.
  70. Butler, M.D.; Wang, Y.Y.; Cartmell, E.; Stephenson, T. Nitrous oxide emissions for early warning of biological nitrification failure in activated sludge. Water Res. 2009, 43, 1265–1272.
  71. Yu, R.; Kampschreur, M.J.; van Loosdrecht, M.C.M.; Chandran, K. Oxide and Nitric Oxide Generation during Transient Anoxia. Environ. Sci. Technol. 2010, 44, 1313–1319.
  72. Chung, Y.C.; Chung, M.S. BNP Test to Evaluate the Influence of C/N Ratio on N2O Production in Biological Denitrification. Water Sci. Technol. 2000, 42, 23–27.
  73. Schulthess, R.V.; Gujer, W. Release of nitrous oxide (N2O) from denitrifying activated sludge: Verification and application of a mathematical model. Water Res. 1996, 30, 521–530.
  74. Song, K.; Harper, J.W.F.; Hori, T.; Riya, S.; Hosomi, M.; Terada, A. Impact of carbon sources on nitrous oxide emission and microbial community structure in an anoxic/oxic activated sludge system. Clean Technol. Environ. Policy 2015, 17, 2375–2385.
  75. Adouani, N.; Lendormi, T.; Limousy, L.; Sire, O. Effect of the carbon source on N2O emissions during biological denitrification. Resour. Conserv. Recycl. 2010, 54, 299–302.
  76. Zhang, X.; Wang, X.; Zhang, J.; Huang, X.; Wei, D.; Lan, W.; Hu, Z. Reduction of nitrous oxide emissions from partial nitrification process by using innovative carbon source (mannitol). Bioresour. Technol. 2016, 218, 789–795.
  77. Su, Q.; Domingo-Félez, C.; Jensen, M.M.; Smets, B.F. Abiotic Nitrous Oxide (N2O) Production Is Strongly pH Dependent but Contributes Little to Overall N2O Emissions in Biological Nitrogen Removal Systems. Environ. Sci. Technol. 2019, 53, 3508–3516.
  78. Hooper, A.B.; Vannelli, T.; Bergmann, D.J.; Arciero, D.M. Enzymology of the oxidation of ammonia to nitrite by bacteria. Antonie Leeuwenhoek 1997, 71, 59–67.
  79. Schreiber, F.; Wunderlin, P.; Udert, K.M.; Wells, G.F. Nitric oxide and nitrous oxide turnover in natural and engineered microbial communities: Biological pathways, chemical reactions, and novel technologies. Front. Microbiol. 2012, 3, 372.
  80. Twining, B.S.; Mylon, S.E.; Benoit, G. Potential role of copper availability in nitrous oxide accumulation in a temperate lake. Limnol. Oceanogr. 2007, 52, 1354–1366.
  81. Moffett, J.W.; Tuit, C.B.; Ward, B.B. Chelator-induced inhibition of copper metalloenzymes in denitrifying bacteria. Limnol. Oceanogr. 2012, 57, 272–280.
  82. Ren, Y.; Ngo, H.H.; Guo, W.; Ni, B.J.; Liu, Y. Linking the nitrous oxide production and mitigation with the microbial community in wastewater treatment: A review. Bioresour. Technol. Rep. 2019, 7, 100191.
  83. Schalk-Otte, S.; Seviour, R.J.; Kuene, J.G.; Jetten, M.S.M. Nitrous oxide (N2O) production by Alcaligenes faecalis during feast and famine regimes. Water Res. 2000, 34, 2080–2088.
  84. Knowles, R. Denitrification. Microbiol. Rev. 1982, 46, 43–70.
  85. Hanaki, K.; Hong, Z.; Matsuo, T. Production of nitrous oxide gas during denitrification of wastewater. Water Sci. Technol. 1992, 26, 1027–1036.
  86. Itokawa, H.; Hanaki, K.; Matsuo, T. Nitrous oxide production in high-loading biological nitrogen removal process under low cod/n ratio condition. Water Res. 2001, 35, 657–664.
  87. Andalib, M.; Taher, E.; Donohue, J.; Ledwell, S.; Andersen, M.H.; Sangrey, K. Correlation between nitrous oxide (N2O) emission and carbon to nitrogen (COD/N) ratio in denitrification process: A mitigation strategy to decrease greenhouse gas emission and cost of operation. Water Sci. Technol. 2018, 77, 426–438.
  88. Christensen, M.H.; Lie, E.; Welander, T. A Comparison Between Ethanol and Methanol as Carbon Sources for Denitrification. Water Sci. Technol. 1994, 30, 83–90.
  89. Gruber, W.; Von Kanel, L.; Vogt, L.; Luck, M.; Biolley, L.; Feller, K.; Moosmann, A.; Krahenbühl, N.; Kipf, M.; Loosli, R.; et al. Estimation of countrywide N2O emissions from wastewater treatment in Switzerland using long-term monitoring data. Water Res. X 2021, 13, 100122.
  90. Quan, X.; Zhang, M.; Lawlor, P.G.; Yang, Z.; Zhan, X. Nitrous oxide emission and nutrient removal in aerobic granular sludge sequencing batch reactors. Water Res. 2012, 46, 4981–4990.
  91. Amatya, I.M.; Kansakar, B.R.; Tare, V.; Fiksdal, L. Role of pH on biological Nitrification Process. J. Inst. Eng. 2011, 8, 119–125.
  92. Meyerhof, O.F. Process Chemistry and Biochemistry of Nitrification. Stud. Environ. Sci. 1916, 54, 55–118.
  93. Van Hulle, S.W.H.; Vandeweyer, H.J.P.; Meesschaert, B.D.; Vanrolleghem, P.A.; Dejans, P.; Dumoulin, A. Engineering aspects and practical application of autotrophic nitrogen removal from nitrogen rich streams. Chem. Eng. J. 2010, 162, 1–20.
  94. Suzuki, I.; Dular, U.; Kwok, S.C. Ammonia or ammonium ion as substrate for oxidation by Nitrosomonas europaea cells and extracts. J. Bacteriol. 1974, 120, 556–558.
  95. Anthonisen, A.C.; Loehr, R.C.; Prakasam, T.B.S.; Srinath, E.G. Inhibition of nitrification by ammonia and nitrous acid. J. Water Pollut. Control Fed. 1976, 48, 835–852.
  96. Vadivelu, V.M.; Keller, J.; Yuan, Z. Effect of free ammonia on the respiration and growth processes of an enriched Nitrobacter culture. Water Res. 2007, 41, 826–834.
  97. Vadivelu, V.M.; Yuan, Z.; Fux, C.; Keller, J. The inhibitory effects of free nitrous acid on the energy generation and growth processes of an enriched Nitrobacter culture. Environ. Sci. Technol. 2006, 40, 4442–4448.
  98. Jimιnez, E.; Gimιnez, J.B.; Ruano, M.V.; Ferrer, J.; Serralta, J. Effect of pH and nitrite concentration on nitrite oxidation rate. Bioresour. Technol. 2011, 102, 8741–8747.
  99. Ruiz, G.; Jeison, D.; Chamy, R. Nitrification with high nitrite accumulation for the treatment of wastewater with high ammonia concentration. Water Res. 2003, 37, 1371–1377.
  100. Thörn, M.; Sörensson, F. Variation of nitrous oxide formation in the denitrification basin in a wastewater treatment plant with nitrogen removal. Water Res. 1996, 30, 1543–1547.
  101. Pan, Y.; Ye, L.; Ni, B.J.; Yuan, Z. Effect of pH on N2O reduction and accumulation during denitrification by methanol utilizing denitrifiers. Water Res. 2012, 46, 4832–4840.
  102. Grunditz, C.; Dalhammar, G. Development of nitrification inhibition assays using pure cultures of Nitrosomonas and Nitrobacter. Water Res. 2001, 35, 433–440.
  103. Van Hulle, S.W.H.; Volcke, E.I.P.; Teruel, J.L.; Donckels, B.; van Loosdrecht, M.C.M.; Vanrolleghem, P.A. Influence of temperature and pH on the kinetics of the SHARON nitritation process. J. Chem. Technol. Biotechnol. 2007, 82, 471–480.
  104. Hellinga, C.; van Loosdrecht, M.C.M.; Heijnen, J.J. Model based design of a novel process for nitrogen removal from concentrated flows. Math. Comput. Model. Dyn. Syst. 1999, 5, 351–371.
  105. Boiocchi, R.; Gernaey, K.V.; Sin, G. A novel fuzzy-logic control strategy minimizing N2O emissions. Water Res. 2017, 123, 479–494.
  106. Poh, L.S.; Jiang, X.; Zhang, Z.; Liu, Y.; Ng, W.J.; Zhou, Y. N2O accumulation from denitrification under different temperatures. Appl. Microbiol. Biotechnol. 2015, 99, 9215–9226.
  107. Weiss, R.F.; Price, B.A. Nitrous oxide solubility in water and seawater. Mar. Chem. 1980, 8, 347–359.
  108. Zumft, W.G. Cell Biology and Molecular Basis of Denitrification. Microbiol. Mol. Biol. Rev. 1997, 61, 533–616.
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