Emission Factor (EF) Calculation
Emission factor definition
The emission factor (EF) is expressed as the percentage of influent total nitrogen emitted as \(\mathrm{N_2O\text{-}N}\) over the evaluation period.
For a time series with time step \(\Delta t\) in days, the EF is calculated as:
\[EF_{N_2O}
=
100
\frac{
\sum_{n}
E_{N_2O,tot,n}\,\Delta t
}{
\sum_{n}
\left(
\frac{Q_{in,n}\,TN_{in,n}}{1000}
\right)\Delta t
}\]
where:
\(E_{N_2O,tot,n}\) is the total emitted N₂O mass rate at time step \(n\), in \(\mathrm{kg \; N \; d^{-1}}\),
\(Q_{in,n}\) is the influent flow rate at time step \(n\), in \(\mathrm{m^3 \; d^{-1}}\),
\(TN_{in,n}\) is the influent total nitrogen concentration at time step \(n\), in \(\mathrm{g \; N \; m^{-3}}\),
\(\Delta t\) is the time step in days.