Work

Pathways to mitigating nitrous oxide emissions throughout the nutrient wastewater circular economy

Year: 2025

Type: article

Abstract: s Nitrous oxide (N 2 O) is one of the world’s most potent greenhouse gases (GHG) originating from microbial metabolic interactions during nitrification and denitrification processes. Despite the significance of this gas from wastewater treatment plants (WWTPs), the efforts of GHG reduction are lacking in this domain. Combined with the need to recover critical nutrients for fertilisers, combat climate change, stabilise food prices from fertiliser price shocks, and improve financial channels for WWTP processes - the nutrient circular economy (CE) is proposed as a method for mitigating and sequestering GHG emissions. This paper proposes a variety of pathways to combat N 2 O emissions. To effectively mitigate N 2 O emissions, proper monitoring methods such as the use of machine learning (ML), geospatial systems to map emissions, sharing of data for robust modelling, and sensor accuracy improvements are needed. Mitigation strategies include embedding respiring microorganisms, biochar inductions, use of recovered struvite as fertiliser, enriching denitrifying microorganisms, introducing beneficial microbes during wastewater recovery, and promoting the use of slow-release mechanisms in CE fertilisers. Controls should be taken to mitigate downstream emissions occurring at the soil-application stages via appropriate fertiliser compositions and modified farming practices, which remains the single largest source of emission. Estimations for N 2 O emissions will continue to be challenging due to the heterogenous nature of wastewater, different plant processes, and varying presence and concentrations of diverse microorganisms.

Source: Desalination and Water Treatment

DOI: 10.1016/j.dwt.2025.101611

Authors: Allan Soo, Li Gao, Ho Kyong Shon

Institutions: University of Technology Sydney, RMIT University

Language: English

Topic: Wastewater Treatment and Nitrogen Removal

Subfield: Pollution

Field: Environmental Science

Domain: Physical Sciences

SDGs: Responsible consumption and production, Climate action, Clean water and sanitation

Open Access status: gold

Estimated APC paid: $1,000