domestic sewage; scarcity; water security; alternative source

In regions facing a water deficit, such as the Brazilian northeast, the reuse of effluents from domestic Wastewater Treatment Plants (WWTP) presents itself as an alternative to alleviate pressures and reduce contamination of water sources. The practice is directly related to the 2030 Agenda for sustainable development, more specifically within Sustainable Development Goal (SDG) 6 – drinking water and sanitation, being one of the tools for achieving the proposed goals. In this context, this thesis' main objective is to evaluate the potential for wastewater reuse from domestic sewage treatment from public sanitation systems as a strategy for improving water security in Pernambuco, through a case study of the Ipojuca river basin . The methodology adopted has a qualitative and quantitative approach, consisting of the evaluation of water resources management instruments being implemented in the basin; quantitative and qualitative analysis of the supply of reused water; characterization and mapping of demands (industry and irrigation), identification of opportunities and challenges to the practice of reuse in the basin. As a result, 12 WWTPs were identified in 10 municipalities with the potential to produce 76,188 m³/day of reused water. In terms of water quality, for the analyzed parameters, the stations demonstrated good performance, where the effluent could be used for restricted uses without the need for additional treatment. However, except in Ipojuca and Gravatá, the demands for irrigation and industry identified up to 20 km away from the WWTPs are lower than the effluent production. The low level of implementation of water management instruments such as system of classification and water charges is also highlighted, and it is recommended that a water permit be created for producers of reclaimed water in the basin. Finally, it is concluded that the Ipojuca river basin has a reuse potential to be explored as an alternative to improving water availability and reducing the release of effluents into the Ipojuca River. The results obtained through unprecedented analysis in the basin serve as a reference for those formulating and executing water resource management policies, as well as providing incentives for potential producers and consumers of reclaimed water.