Integration of environmental and economic performance of processes.: Case study on advanced oxidation processes for wastewater treatment

The aim of this paper is to introduce an easy-to-use environmental-economic index (EEI) which can be used for comparative purposes when assessing processes and services. The EEI differs from traditional ratio-based Eco-efficiency indicators, since it is defined instead as the sum of two components, one corresponding to environmental performance and the other to economic performance. In order to show the calculation of this index and its potential usefulness, it is used in an example where several Advanced Oxidation Processes (AOPs) for wastewater treatment are compared based on their life-cycle greenhouse gas emissions and life-cycle cost. The options assessed are: solar-driven photo-Fenton, lamp-driven photo-Fenton, and ozonation. Solar-driven photo-Fenton appears as the preferable option from an integrated enviromnental-economic point of view, if the environmental and economic dimensions are equally weighed. The case study shows that EEI captures, in a single score, both environmental and economic information from a given set of alternative options, allowing us to assess their relative performance in a simple way.