Table 4.
Share of nitrogen emissions as reactive nitrogen (Nr) and molecular nitrogen (N2) in the different scenarios analysed. Percentages are referred to the N entering the system.
| Nr |
N2 |
Literature sources on which scenarios are built | |||||||
|---|---|---|---|---|---|---|---|---|---|
| Baseline | Improved | Advanced | Combined | Baseline | Improved | Baseline | Combined | ||
| Wastewater - collected without treatment | 100% | 100% | 100% | 100% | 0% | 0% | 0% | 0% | Author's Assumption |
| Wastewater - primary treatment | 90% | 90% | 90% | 90% | 0% | 0% | 90% | 90% | Bonomo (2008) |
| Wastewater - secondary treatment | 75% | 75% | 75% | 75% | 0% | 0% | 75% | 75% | Bonomo (2008) |
| Wastewater - tertiary treatment | 30% | 10% | 30% | 10% | 51% | 71% | 30% | 10% | Mc Carty (2018) |
| N recovery | 7% | 2% | 7% | 2% | 12% | 16% | 7% | 2% | Pradhan et al. (2017) |
| Composting | 24% | 19% | 24% | 19% | 2% | 2% | 2% | 2% | Körner et al. (2009). |
| Anaerobic digestion + direct application | 0% | 0% | 0% | 0% | 0% | 0% | 0% | 0% | |
| Anaerobic digestion + composting | 24% | 19% | 24% | 19% | 2% | 2% | 2% | 2% | As composting |
| Incineration | 30% | 30% | 30% | 30% | 0% | 0% | 0% | 0% | |
| Landfill | 8% | 7% | 8% | 7% | 39% | 41% | 39% | 41% | Cossu et al. (2005) and leachate sent to tertiary treatment |
| Home composting | 5% | 5% | 5% | 5% | 54% | 54% | 54% | 54% | Andersen et al. (2011) |