Tratamento e reúso de águas residuárias em instituição de ensino: avaliação da ETE do IFRN de Ipanguaçu

Abstract

The lack of sewage treatment, or inadequate treatment combined with improper disposal, can pose serious risks to the population. A decentralized sewage treatment system is essential to reducing the burden on the municipal system; however, its efficiency requires continuous monitoring. In this context, this study aims to monitor, characterize, and evaluate raw and treated sewage on the IFRN-Ipanguaçu campus, identifying specific corrections and enabling on-campus wastewater reuse, promoting sustainability and reducing water supply costs. This research is classified as applied, quantitative, exploratory, and descriptive. Initially, data were obtained from the facility, followed by an assessment of the campus's sewage treatment, demonstrating the possibility of reusing treated wastewater to promote sustainability and financial savings. As a technological product, a management plan for the IFRN Sewage Treatment Plants (STPs) was developed to maximize process efficiency. Overall, the WWTP at the IFRN-Ipanguaçu campus presented satisfactory organic matter and solids removal performance, with average BOD₅ and COD efficiencies of 81% and 72%, and TSS above 80%, meeting the limits established by CONAMA Regulation No. 430/2011. Nutrient removal was low, a desirable characteristic for agricultural reuse, provided it is controlled in accordance with CONAMA Resolution No. 503/2021. Disinfection promoted a 92.5% reduction in thermotolerant coliforms; however, operational failures resulted in average concentrations of approximately 10⁶ MPN/100 mL. According to WHO (2006) guidelines, this value falls only within the restricted irrigation category (option H), applicable to localized irrigation systems without occupational risk. Under these conditions, reuse is feasible for the fertigation of less demanding crops, such as forage grasses, provided continuous monitoring is carried out. Despite these advances, the evaluated system still requires structural and operational corrections. This research, a pioneer in the scientific evaluation of the IFRN – Ipanguaçu WWTP, highlights both the potential for agricultural reuse and the need for interventions to ensure operational sustainability, serving as a technical reference for managers and operators of similar compact systems.