Avaliação do Ciclo de Vida (ACV) de lodo gerado em estação de tratamento de esgoto no município de São José do Rio Preto - SP

Abstract

Water supply and wastewater treatment activities play an essential role in promoting public health and environmental protection. However, like other industrial processes, sanitation systems generate different types of waste, with sludge being the main by-product of both Water Treatment Plants (WTPs) and Wastewater Treatment Plants (WWTPs). Despite their high moisture content, these sludges are classified as solid waste and must comply with the guidelines of the Brazilian National Solid Waste Policy (PNRS – Law No. 12,305/2010). This research aims to analyze the potential environmental impacts associated with sludge generated by treatment systems in the municipality of São José do Rio Preto/SP, based on Life Cycle Assessment (LCA). The methodological procedure is structured into four phases: (i) bibliographic review, bibliometric analysis, and systematic literature review; (ii) collection and systematization of primary data related to water and wastewater treatment processes in the municipality of São José do Rio Preto/SP for the construction of the Life Cycle Inventory (LCI); (iii) Life Cycle Impact Assessment (LCIA); and (iv) interpretation of the results. The LCA was conducted in accordance with ABNT NBR ISO 14040 and 14044 standards, considering 1 kg of dewatered sludge as the functional unit. The LCIA was performed using the ReCiPe 2016 method, midpoint (H) approach, with the support of the OpenLCA software, and the results were analyzed through interpretation and contribution analysis of processes for the impact categories Climate Change, Fossil Resource Scarcity, Terrestrial Ecotoxicity, Human Toxicity (non-carcinogenic), and Freshwater Eutrophication. The results indicate that the environmental impacts of the treatment system are predominantly associated with operational stages. Contribution analysis identified electricity consumption as the main environmental hotspot of the system. These findings demonstrate the potential of LCA as a decision-support tool for the environmental management of sanitation residues by enabling the identification of critical processes and opportunities for improvement.