Reutilização de água: contribuição para um modelo de apoio à decisão

Abstract

One of the consequences of climate change is the reduction of water availability,

especially in regions that already suffer from low rainfall, such as the Brazilian semi- arid region. Among the measures to adapt to this reality is the reuse of water. Despite

several success stories and available treatment technologies, the percentage of water reuse is still low in global terms. The difficulty of implementation is due to aspects that must be considered, such as technical, environmental, social, political, economic, legislative and even local climate conditions. The objective of this thesis was to develop a model to support the decision for water reuse, containing the indicators and parameters relevant to this decision. The literature review identified 4 key indicators (technical, social, environmental and economic) and 12 parameters (WWTP safety, transport complexity, existence of legislation, risk to health and the environment, energy consumption, degree of acceptance and necessity, universal collection and treatment, necessary investment, operating costs and economic benefits) with direct

influence on a decision for water reuse. The study carried out was analytical- descriptive and operational research to support decision-making. The multi-criteria

Fuzzy Analytic Hierarchy Process (FAHP) method was used to determine the weights of indicators and parameters and subsequent construction of the decision support model based on the potential reuse feasibility index (IVR). The developed model was applied to the city of Aquiraz, Ceará, Brazil and the IVR found was 81%, classified as Very High Viability for agriculture purpose. The results were subjected to a sensitivity analysis that indicated consistency of the global results obtained by the FAHP method.