Modelo para definição do uso de sistemas adequados para tratamento de esgoto urbano em pequenas e médias localidades

Abstract

The correct definition of urban wasterwater treatment systems to meet different scenarios is a complex task due to the varied number of treatment systems available in addition to the diversity of characteristics presented in each specific scenario. In order to guarantee the best alternative selection for each case, an in-depth analysis of the intrinsic particularities of this theme is necessary. This work provides a model for selecting treatment systems according to local needs and lists the indicators considered relevant to support the decision maker in identifying criteria for choosing the alternative with the greatest commitment to the project objectives. The model considers four evaluation dimensions, economic, technical, environmental and social, which are evaluated through an integrated approach that employs ELECTRE, COPELAND, AHP, SIMOS and PROMETHEE together to select the best alternative. COPELAND is used to analyze the structure of the selection criteria selection problem, the AHP and the SIMOS method to determine the criteria weights, and the PROMETHEE method is used to obtain the final classification and do a sensitivity analysis by changing the criteria weights. The methodology was tested for three different scenarios. Twenty-seven treatment technologies were evaluated, and previously measured. In the three applications, the wetland treatment process was observed in the ranks among the first alternatives, due to its reliability, durability, flexibility and robustness. The results showed that the integrated methods can be successfully used to solve sanitation problems. This work will assist in the decisions to analyze, design and evaluate the alternatives for effluent treatment, both for individual or joint solutions.