Page 275 - Materials Chemistry, Second Edition

256 Life Cycle Assessment of Wastewater Treatment

TABLE 12.4 (CONTINUED)
LCA Characteristics of the LCA Studies Reviewed

LCA Sensitivity
Study approach LCA model Normalization Analysis
Schwaickhardt et al. (2017) Midpoint and ReCiPe Yes No
endpoint
Lutterbeck et al. (2017) Midpoint and ReCiPe Yes No
endpoint
Lu et al. (2017) Endpoint EcoIndicator 99 No No
Bai et al. (2017) Midpoint CML 2001 Yes No
Li et al. (2017) Midpoint CML 2001 Yes No

process, providing information about environmentally friendly alternatives for future
projects. In addition, the expansion of the scope to other components of the system
could provide relevant information, as is noted in Barjoveanu et al. (2014), El-Sayed
et al. (2010), and Limphitakphong et al. (2016).

12.4.6 funcTional uniT
The selection of the functional unit is acknowledged as a crucial point in an LCA.
So, from the review, it is noted that in the huge majority of papers analyzed in which
LCA was carried out, the volume of wastewater managed was expressed in cubic
meters as functional unit. Indeed, from Figure 12.4, it is noted that 29 of 39 studies
adopted cubic meters of wastewater as functional unit. In second position, but with
a much lower occurrence, it is observed that six studies used person equivalent (PE)
as functional unit. This preference for relating resource consumption and emissions
to wastewater volume was expected, as it is a measure normally available from the
operational monitoring database.

30 28

25
Number of publications 15
20

10
5
1 1 6
0
3
kg Ton Person m of
of COD of sludge equivalent wastewater
FIGURE 12.4 Functional unit adopted in the LCA studies reviewed.