Quantitative sustainability analysis of water desalination - A didactic example for reverse osmosis

Water desalination continues to evolve to a currently mature stage that, similarly to all large human endeavors, must be planned, designed, and operated according to the quantitative holistic sustainability paradigm and criteria that are defined by the interrelated aspects of the environmental, economic, and social pillars of the endeavor. A methodology for such evaluation was described in [1], including equations for formulating a composite sustainability index as a function of relevant parameters, which thus allows mathematical analysis in general and sensitivity analysis and optimization in particular. This is the first paper that demonstrates this methodology and its use for desalination by presenting an example of a comprehensive and detailed original sustainability analysis of reverse osmosis (RO) desalination plants and of their comparison. It includes the selection and calculation of metrics (for simplicity, a small number and partially synthetic) and weights, as well as their aggregation to a composite sustainability indicator, using typical data values. The aggregation is performed by an original concept of impact quantification and monetization. An analysis of sensitivity to choice of weights and to the combined environmental and social impact factors was conducted. The presented sustainability analysis example should be helpful for both didactic and practical purposes, and the methodology is flexible, modular, adaptable, and enhancable to meet other and evolving needs.