Avaliação do potencial técnico e econômico de reúso para fins não potáveis de efluente líquido de uma ETE: estudo de caso em um complexo hoteleiro em Maceió/AL

Abstract

Water is a vital and finite resource, with less than 1% available for human consumption. Its scarcity is exacerbated by the lack of basic sanitation and unregulated water extraction. The reuse of effluents emerges as a sustainable solution, recognized in global initiatives such as Agenda 21 and the 2030 Agenda. In Brazil, despite regulations governing reuse, its implementation remains limited. In this context, the present study assessed the potential for reusing treated effluent from a wastewater treatment plant (WWTP) located in a hotel complex in Maceió, Alagoas, focusing on non-potable applications. The research considered the qualitative and quantitative characterization of effluent, compliance with current legislation, identification of applicable reuse methods, and the economic feasibility of implementing a reuse system on site. Using secondary data, the study analyzed treatment processes such as UASB reactors, submerged aerated filters, and bioremediation, and discussed national reuse regulations. The results highlighted opportunities to optimize water management, reinforcing effluent reuse as a sustainable and economically viable strategy aligned with global sustainable development goals. The analysis of effluent flow rates, based on an average water consumption, was of 407,33 m³/day, revealed a significant surplus, indicating that the system could meet reuse demands and allow for expansion. Qualitative characterization showed that although the effluent complies with discharge limits, it does not meet reuse standards, particularly with respect to thermotolerant coliforms, biochemical oxygen demand (BOD), and turbidity, necessitating the addition of an advanced treatment system. The economic analysis demonstrated that implementing the reuse system is feasible, with a net present value (NPV) of R$ 38,384.72 and a payback period of 11.37 years. While financial returns are gradual, the project proves to be advantageous from both economic and environmental perspectives.