Modelling the N2O Emissions in Municipal Wastewater Treatment Plants under Dynamic Conditions

10 pages•Published: September 20, 2018

Theoni Massara, Borja Solis Duran, Albert Guisasola, Evina Katsou and Juan Antonio Baeza

Abstract

Nitrous oxide (N2O), a greenhouse gas with a significant global warming potential, can be produced during the biological nutrient removal in wastewater treatment plants (WWTPs). N2O modelling under dynamic conditions is of vital importance for its mitigation. Following the activated sludge models (ASM) layout, an ASM-type model was developed considering three biological N2O production pathways for a municipal anaerobic/anoxic/aerobic (A2/O) WWTP performing chemical oxygen demand, nitrogen and phosphorus removal. Precisely, the N2O production pathways included were: nitrifier denitrification, hydroxylamine oxidation, and heterotrophic denitrification, with the first two linked to the ammonia oxidizing bacteria (AOB) activity. A stripping effectivity (SE) factor was used to mark the non-ideality of the stripping modelling. With the dissolved oxygen (DO) in the aerobic compartment ranging from 1.8 to 2.5 mg L-1, partial nitrification and high N2O production via nitrifier denitrification occurred. Therefore, low aeration strategies can effectively lead to a low overall carbon footprint only if complete nitrification is guaranteed. After suddenly increasing the influent ammonium load, the AOB had a greater growth compared to the NOB. N2O hotspot was again nitrifier denitrification. Especially under concurring partial nitrification and high stripping (i.e. combination of low DO and high SEs), the highest N2O emission factors were noted.

Keyphrases: dissolved oxygen, dynamic conditions, emission factor, greenhouse gases, mathematical modelling, nitrous oxide

In: Goffredo La Loggia, Gabriele Freni, Valeria Puleo and Mauro De Marchis (editors). HIC 2018. 13th International Conference on Hydroinformatics, vol 3, pages 1340-1349.

Links:	https://easychair.org/publications/paper/TSKZ
	https://doi.org/10.29007/w6rq

BibTeX entry

@inproceedings{HIC2018:Modelling_N2O_Emissions_Municipal,
  author    = {Theoni Massara and Borja Solis Duran and Albert Guisasola and Evina Katsou and Juan Antonio Baeza},
  title     = {Modelling the N2O Emissions in Municipal Wastewater Treatment Plants under Dynamic Conditions},
  booktitle = {HIC 2018. 13th International Conference on Hydroinformatics},
  editor    = {Goffredo La Loggia and Gabriele Freni and Valeria Puleo and Mauro De Marchis},
  series    = {EPiC Series in Engineering},
  volume    = {3},
  publisher = {EasyChair},
  bibsource = {EasyChair, https://easychair.org},
  issn      = {2516-2330},
  url       = {/publications/paper/TSKZ},
  doi       = {10.29007/w6rq},
  pages     = {1340-1349},
  year      = {2018}}

Download PDF Open PDF in browser