Proposição de diretrizes para o estabelecimento de um modelo de negócio para reúso de água de estação de tratamento de esgoto aplicado à mineração

Abstract

The balancing water availability and demand has been a global challenge. Population and economic growth; water scarcity events; lack of basic and environmental sanitation; and inadequate governance have increased the pressure on water resources, resulting in water crises. In the mining sector, water is essential, whether for the production process or for secondary activities. Thus, seeking alternative sources and less conflict with other users is a requirement for productive safety. One of the opportunities is to promote water reuse from sanitary effluents as an alternative source for supplying mining enterprises. The new law of sanitation (Law 14.026/2020) opens an opportunity for the improvement of basic sanitation, and it includes, as a goal, the reuse of sanitary effluents. So, in this dissertation, the objective was to propose the main guidelines to establish the business model for the reuse of water from wastewater treatment plants for non-potable use in the mining sector. For this purpose, a bibliographic and bibliometric review was conducted to outline the current landscape of water reuse. The guidelines for establishing the business model were elaborated by adapting the Front End Loading (FEL) methodology, recommended for the conception, development, execution, and operation of complex, large-scale projects. As a result, 12 main guidelines were defined. To verify the practical applicability of these guidelines, the Laboreaux WWTP, located in the city of Itabira, Minas Gerais - as producer and supplier of water for reuse - and the Itabira Mining Complex owned by Vale S.A. - as user of this water - were presented as case studies. The conception study for the non-potable water reuse project was based on public information made available by Vale S.A and by the Water and Sewage Service of Itabira (SAAE). The information was complemented with field visits. The technical, economic, and environmental feasibility of 5 alternatives was analyzed, with different layouts of the pipeline and reservoir. Alternative 2, considering the Pontal dam as the reuse water reservoir, proved to be the most feasible. The estimated cost considering the pumping system and adductor was around 10 million. It is expected that public and private investments will be directed to sanitation to make the implementation of water reuse systems feasible.