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Characterisation Method Information
Characterisation Method Name:
COD impact on NEX
Date Completed:
Principal Method Name:
EPS: equivalency method using N-tot as a reference
Method Description:
NEX is Normalised EXtinction of species.


The characterisation factor is determined by an equivalency method using N-tot as a

Equivalency factor

According to Lindfors et al. (1995), each mole of nitrogen corresponds to 8.6 mole of
consumed oxygen in a N-limited aquatic system scenario. Normally, only a part of the
COD is actually mineralised in such a way as it contributes to oxygen-free water. This
part is assumed to be 50%. The equivalency factor is therefore equal to = 0.5*14/(8.6*16) = 0.0508 kg/kg

Calculation of characterisation factor

The characterisation factor for N-tot is determined in "N-tot impact on NEX" to 1.8×E-13 . The characterisation factor for COD is thus 0.0508*1.8E-13 = 9.18E-15 NEX/kg BOD.

Literature Reference:
Lindfors, L.G.,Christiansen, K., Hoffman, L., Virtanen, Y., Juntilla, V. Leskinen, A., Hanssen, O-J., Rønning, A., Ekvall, T. and Finnveden, G., LCA-Nordic, Technical report No 10, Tema Nord 1995:503, Nordic Council of Ministers, Copenhagen 1994.
Methodological Range:
All lakes, surface waters and oceans on the globe 1990.

Existing Characterisation Factors of COD impact on NEX
Characterisation Parameter Category Indicator Impact Indication Principle Aspect Substance Quantity Unit Notes
CFactor NEX EPS/2000
Type = Emission
Direction = Output
Media = Water
Geography = *
COD 9.18E-15 NEX/kg