Application of the Analytic Hierarchy Process for selection of alternative solutions for domestic wastewater treatment

Abstract

Choosing the best form of domestic sewage treatment requires analyses that allow decision-making on the ideal solutions for implementation, according to the particularities of each regionality, especially when it comes to rural and isolated areas dependent on decentralized solutions. Thus, through this study, the Analytic Hierarchy Process (AHP) was used from a data collection on simplified treatment systems existing in temperate municipalities without a dry season, to evaluate priority systems in different scenarios considering environmental, social, and technical-economic indicators. Among the results for the scenarios performed, the compact upflow anaerobic reactor, the septic tank and anaerobic filter, and the septic tank and built-in flooded system of vertical subsurface flow were the solutions that proved to be the most indicated following the indicators used and the existing information. It is noteworthy that the results refer to the study area in question, and new applications of the method are needed in different climatic regions. From the application of the methodology, the AHP tool indicated that it is a viable method to assist in decision-making regarding the selection of sewage treatment systems in rural areas, which, being tied to municipal planning in basic sanitation, assists in the optimization of existing resources. The sensitivity of the method showed the importance of its application with data collected on site, in addition to the incorporation of public and experts opinions in the contribution of the degree of importance of the criteria and indicators used.