Implantação de projeto de reúso em estações de tratamento de esgoto: gestão e análise em escala de bacia hidrográfica

Abstract

Water resource management in Brazil reached a significant milestone with Water Law No. 9,433/97, which established the National Water Resources Policy and established the river basin as a territorial unit of management, promoting a more integrated and effective approach to these resources. The increasing pollution of water resources and the environmental challenges related to their availability reinforce the urgent need to adopt sustainable practices, such as reuse, to ensure water security and sustainability. In this context, this study aimed to analyze and establish criteria to guide the evaluation and decision-making process for the implementation of water reuse projects for industrial purposes in sewage treatment plants, based on integrated river basin management.The study was based on an analysis of the Joanes River Basin, located in the Salvador Metropolitan Region (RMS) within the Recôncavo Norte and Inhambupe Water Planning and Management Region (RPGA). The basin was selected for its water resource availability, industrial growth, water-related economic activities, and regional importance for supply and socioeconomic development. The methodology included eight stages, including a literature review, area characterization, mapping and classification of WWTPs, availability and demand analysis, pilot project definition, georeferencing, industry-WWTP distance analysis, pilot project structuring, and potential risk assessment. The results indicated high reuse potential, capable of meeting more than 100% of industrial demand in almost all sections of the basins representing a strategic opportunity for rational water use. The mapped potential risks allowed for an integrated approach to reuse, assessing its impacts on project viability and establishing controls to ensure greater acceptance, operational efficiency, and sustainability of the reuse system.The analysis of the distance between the Pilot WWTP and users, combined with the economic evaluation, demonstrated that, despite its infeasibility on a small scale, the study was essential for testing the technical and economic viability of reuse, applying the defined premises and criteria in practice. Thus, the product of this master's research resulted in a robust evaluation protocol, serving as a technical instrument and guiding document for the systematic assessment of the feasibility of implementing water reuse projects in WWTPs, highlighting the study's relevance for sustainable water management strategies and its potential for replication in other river basins.