An innovative greywater treatment system for urban areas ... - SuSanA

ate in combination with high population density. An overview of the map is given in Figure
26.
This is a rough estimation of ideal application areas for MBR greywater recycling plants by
utility analysis. Due to the limited time of this work, a detailed evaluation of worldwide regions
divided into small sections was not possible. In a further study, an investigation based on
geographic information systems (GIS) could supply more detailed results. It is conceivable,
to utilise cartographic modelling, where several thematic layers, such as water scarcity, water
quality etc. could be put on top of each other to evaluate the best compliance with the
conditions of utility analysis.
Figure 26: Presentation of countries and regions identified by trimmed-down utility analysis, ideal
for greywater treatment via MBR technology; (by K. Löw)
This approach, to assess four environmental aspects, can only outline a rough estimation
of global hotspots, due to regional differences. This analysis has a maximum rating of 21
scores or weighting of 21 %, based on the trimmed-down version of utility matrix. By
identification of water scarcity as an indicator criterion, a pre selection within the assessment
was made. Water scarcity (N1) is the strongest criterion within the whole analysis and thus it
provides a good base to identify countries which are rewarding for the examination of the
international transferability. This strategy aims to exclude incorrect influences from the
analysis. Within the given time of this work it was not possible to assess all countries
according the four criteria, but by starting with the most influencing criterion (N1), mistakes
should be avoided. Even if the other 3 rated criteria have high values, a weighting higher
than 12% as N1 contributes, cannot be achieved by the maximum rating of water quality
(N2), population density (N6), and urbanisation rate (N7). The worldwide view on all four
assessed environmental criteria without any pre-selection may show a slightly different
result, but this was not possible within the limited time of this work.
On top, the estimation is based on the timmed-down analysis with a maximum rating of 21
% of 100 % within the utility analysis, which contributes only one-fifth to the analysis. Hence,
it must be taken into consideration that further aspects, apart from environmental criteria, can
add a serious weight into assessment as well.
This approach can only outline a rough estimation of global hotspots, due to regional
differences. The regional distinctions and conditions of a project may vary widely within
narrow spaces, hence it is only possible to make suggestions and give directions. Here, only
estimations based on environmental aspects are possible. Further meaningful projcets can
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