Modelo de otimização multiobjetivo para outorga de diluição de efluentes e enquadramento de corpos d'água

Abstract

Wastewater dilution authorization and water bodies classification are among the Brazilian Water Resources National Policy instruments that need strategic plans for implementation. These plans must consider economic efficiency, sustainability, flexibility and equity. This thesis presents the development of a multiobjective optimization model that considers in a single objective function different goals involved in the waste-load allocation. The developed model is capable of integrating different objectives and presents as its central idea to minimize costs to maintain receiving body water quality conditions, trying to maximize the improvement of, water bodies dissolved oxygen and biochemical oxygen demand parameters, and also taking into account users equity conditions. The model permits to vary both waste removal efficiencies and outflow discharges into water bodies, allowing the search for greater equity between users. The use of weights in the objective function of the proposed model allows a systemic approach to water management problems, by considering a range of objectives in an integrated and optimized way. It turns possible to reduce the complexity of the solution of problems that involve conflicting demands, by searching for the best compromise that satisfy the existing purposes. The model was integrated into a Decision Support System, that may allows more agile, flexible and efficient water administrative agencies and officials decision-making processes. It was verified, through various case studies, that the use of the developed Decision Support System can make wastewater loads allocation decision processes more orderly, objective and transparent, in the direction of a sustainable management of water resources.