Evaluation of Treated Wastewater Quality for Reuse in the Northern Region of Minas Gerais

Abstract

Objective: This study aims to analyze the quality of effluents treated at three Wastewater Treatment Plants (WWTPs) in the northern region of Minas Gerais, evaluating reuse potential and proposals. Theoretical framework: The practice of reusing sanitary effluents holds significant economic and environmental importance. It conserves water resources allocated for higher priority uses. When assessed and compliant with regulations, effluents become potential water sources for agriculture and urban squares. The trend towards reusing treated effluents presents an alternative to meet water demands that could be satisfied with lower-quality water. Method: The study conducted laboratory analyses of three COPASA MG sewage treatment plants, referred to as WWTPs I, II, and III, between January 2021 and September 2022. Parameters crucial for effluent reuse, including Biochemical Oxygen Demand (BOD), Electrical Conductivity (EC), Hydrogen Potential (pH), Escherichia coli, Sodium Adsorption Ratio (SAR), and viable helminth eggs, were monitored and evaluated. The feasibility of proposed water reuse methods was assessed by analyzing the quality of treated effluents from the three WWTPs, considering that the treatments adhered to the conditions and effluent discharge standards outlined in Joint Normative Decision COPAM and CERH-MG No. 01 of May 5, 2008 (Minas Gerais, 2008), as well as the reuse parameters defined in Normative Decision CERH-MG No. 65/2020 of June 18, 2020 (CERH-MG, 2020). Results and Conclusion: The findings indicate that the effluents treated in the studied WWTPs are suitable for reuse, with potential corrective measures for non-compliant parameters. This allows for irrigation of urban squares, subject to approval by local authorities, and internal irrigation within interested businesses. Research Implications: This approach is highly relevant for fostering discussions on expanding reuse practices and shaping regulations through legislation, norms, and deliberations. Originality: This study stands out due to its in-depth investigation, ensuring a viable water reuse source for localities facing water scarcity, particularly in the northern region of Minas Gerais. This innovative topic, though less explored in literature, is gaining momentum in environmental discourse, thanks to the potential of effluents for agricultural purposes.