Uso da análise multicritério para a seleção de tecnologias de tratamento de efluentes

Abstract

The high number of alternatives added to the number of variables, which are not always measurable and often conflicting, makes choosing the wastewater treatment system a difficult decision process. In order to ensure that the best alternative is selected, a depth analysis is required, which considers the greatest number of decision-making aspects. Therefore, this work has provided a new approach for the selection of wastewater treatment technologies, considering the economic, social, technical and environmental dimensions. The model has followed three stages: the first one was the definition of the model alternatives, which were defined through the economic viability study of 37 technologies usual in Brazil; in the second stage, two groups of criteria were defined, according to flow rate and population, using the Copeland method; and in the third one, the PROMETHEE II method was applied in order to rank the alternatives. Considering the aspects evaluated, the technologies as slow and fast infiltration, anaerobic pond followed by facultative pond were the preferred alternatives for small communities, while UASB systems followed by post-treatment were the less preferred options. For the urban groups the preferred alternatives were: fast infiltration, UASB reactor with anaerobic filter, while the ones with the least potential were the pond systems. The results contribute to the sanitation development, since the work has provided a robust determination process for the selection of the treatment technologies, by evaluating the most relevant criteria.