A multi-criteria approach for the selection of wastewater treatment systems

The inefficiency of Wastewater Treatment Systems (WTS) might be a source of hydrological and environmental pollution, and it also causes problems to public health. The advances of technology have contributed to the development of a diversity of new WTS, but it generates a gap for decision-making regards to the correct use of these treatment systems, with a high number of available alternatives, not easily measurable and often presenting conflicting criteria. In this context, this work presents a literature review aiming to identify relevant economic, social, technical and environmental criteria, which can be used in the selection of WTS. Thus, 48 criteria were identified, as well and their importance was ranked according to a group of academics. Furthermore, an illustrative application was conducted considering 20 available WTS and 12 criteria. The ELECTRE 11 method was used to rank and allocate the most suitable WTS. This research contributes with a multi-criteria model for the evaluation of WTS and to show its relevance in a real world situation

Multi-criteria methodology for selection of wastewater treatment systems with economic, social, technical and environmental aspects

The design, implementation and use of wastewater treatment systems (WTS) are fundamental to mitigate hydrological and environmental problems, and to improve population health. Furthermore, the significant advances in treatment systems technology offer, nowadays, several alternatives and provide many combinations of WTS which must be correctly evaluated and constitute a decision problem for public and private investors and decision makers. Thus, this article presents a multi-criteria methodology based on six steps for the evaluation of WTS considering relevant economic, social, technical and environmental criteria. Particularly, forty-eight main criteria were identified and ranked considering their importance based on the previous literature. This methodology was applied in a Brazilian sanitation company in a specific treatment area of approximately five thousand inhabitants and with recurrent environmental problems, such as the contamination and low efficiency of wastewater treatment. Twenty available alternatives were considered and twelve criteria were selected for this application. The AHP and ELECTRE II methods were combined to weight the different criteria and to rank the most suitable WTS. This methodology can be extended and applied in different scenarios to improve the decision-making process.We thank the Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior -Brazil (CAPES) for the scholarship as part of the aid for this research -Financial Code 001