Page 312 - Materials Chemistry, Second Edition

296 4 Life Cycle Impact Assessment

Only individual substances with a defined equivalence value to Ethene were
considered. For hydrocarbons, often quoted in literature, which are not
precisely defined as substances, an average equivalence value from CML
(1992) is used.
The POCP was determined according to the following formula:
POCP = ∑ m × POCP i
i
i
4.6.1.3 Eutrophication Potential

As an indicator for the calculation of an unwanted nutrient supply the EP is
selected in units of phosphate equivalents. 375) Pollutants or nutrients with
their respective characterisation factor in the context of this project are listed
in Table 4.19.

Table 4.19 Eutrophication potential of substances considered in the context of this
project.

Pollutant PO 4 3− -equivalents (NP )
i

Eutrophication potential (soil)
Nitrogen oxides (NO as NO ) 0.13
x
2
Ammonia (NH ) 0.327
3
Eutrophication potential (water)
Phosphate 1
Phosphorus compounds calculated as P 3.06
Chemical oxygen demand (COD) 0.022
+
Ammonia/ammonium NH /NH 4 0.327
3
Nitrate (NO 3 − )/HNO 3 0.095
Guin´ ee et al. (2002) and Kl̈ opffer (1995).

In a simplified assumption it is presumed that all nutrients released by
air constitute an over-fertilisation of the soil and all nutrients (including
COD substances) of waters lead to eutrophication of water bodies. Since a
nutrient entry into water by air is small compared to that by waste water, this
assumption represents no considerable error.
To distinguish between nutrient entry into soil and into water the contri-
bution to the EP is calculated as the sum of the products of NP and the
released quantities of individual pollutants.

375) CML (1992) and Kl¨ opffer (1995).