Table 2.
Comparison of GHG emissions between NSSS and WWTPs.
| Country | the GHG emissions, Mt CO2e/year |
||
|---|---|---|---|
| NSSS (this study)a | WWTPs (other studies)b | ||
| China | 45.4 | 42.9 | Ren et al. (2021) |
| the USA | 12.9 | 13.4 | USEPA (2020) |
| Greece | 0.3 | 0.9 | Koutsou et al. (2018) |
| Canada | 1.1 | 0.7 | Sahely et al. (2006) |
| Argentine | 2.2 | 3.6 | Santalla et al. (2013) |
| Vietnam | 10.6 | 17.1 | Hoa and Matsuoka (2015) |
| Nigeria | 11.4 | 21.3 | UNFCCC (2021a) |
| Poland | 2.5 | 3.6 | UNFCCC (2021b) |
a
The GHG from NSSS does not include CO2 and N2O, that is, only CH4 emission is considered.
b
The GHG from WWTPs includes CH4 and N2O, but CO2.