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considered. For the case study, as presented above, it is assumed that the
methodology is applicable. However, it is often beneficial, in practical cases, to
insert additional purification methods in the software. The software then
provides an accurate solution, and a decision must then be made as to whether it
should be implemented.
Although the case study is limited to the textile process, it should be stressed
that the pinch methodology applies across all industrial sectors and all plant
sixes, from large power generation (Selby and Tvedt, 1998) and paper fabrication
(Shafiei et al., 2002) plants to relatively small-scale operations within the
pharmaceutical and food industries (Thevendiraraj et al., 2001). However, it is
apparent both from examination of the literature and from personal contact with
engineering firms and research institutes, that real values indicating targeted
water usage and/or achieved water usage are very difficult to find, largely due to
their commercial sensitivity. Moreover, it is very often difficult to be sure that the
indicated result has actually been implemented. However, it can be stated that
water savings of at least 20-60% are achievable through applying water pinch,
as revealed from some of the references cited below.

4.2.7 Conclusion
Software is currently available, based on the water pinch methodology, that
allows one to target the minimal water usage at minimal cost, taking into
account different constraints. Although the methodology is simple when
considering only one contaminant, no purification techniques and no costs, the
methodology requires a skilled engineer or researcher to unravel the whole
concept when taking into account all these elements. Fortunately, the software
currently available provides a means for process engineers and researchers to
tackle these problems without necessitating a fundamental understanding of the
underlying concepts. The software provides a guide that helps the user through
the different steps. Moreover, it is obvious that the software can easily be used to
evaluate many different scenarios and investigate the influence of many
parameters. However, the software tool should not be considered as a plug-and-
play direct answer to the problem. Indeed, without proper insight into the
methodology, processes might be overlooked that play an important role in
reducing the overall water consumption. Identifying solutions that reduce water
consumption at the lowest total cost demands the combined skills of both the
process engineers of the problem holder and experts in water pinch
methodology.

References
Alva-Argaez. A., Kokossis, A.C. and Smith, R. (1998a). An integrated design
approach for wastewater minimisation: theory and applications. IChemE
Research Event, Newcastle, 7-8 April.