Potential and challenges of ozonation for potable reuse in Brazil: an overview of general and practical aspects

Abstract Amidst the increasing challenges related to the quality and availability of water resources, the implementation of effective and safe technologies is crucial to ensure the preservation and security of potable water supply. Water reuse has emerged as a strategic approach to mitigate water scarcity and environmental degradation. However, its large-scale implementation remains limited by technical, regulatory, and public acceptance barriers. In this context, ozonation emerges as a promising alternative capable of purifying wastewater far beyond potable standards. It contributes to mitigating water scarcity and pollution while promoting environmental sustainability and providing significant economic benefits. This review critically evaluates the environmental potential and practical challenges of ozonation for potable water reuse, with a particular focus on the Brazilian context. A structured literature search of peer-reviewed studies (2014–2024) on ozonation for water and wastewater reuse was conducted, covering the fundamentals of ozonation, operational aspects, determination of the optimal ozone dose, application in water reuse, by-products formation, and future perspectives. The findings indicate that ozonation can significantly enhance water quality and safety when appropriately designed and operated, particularly as part of multi-barrier treatment systems. The discussion highlights the need for site-specific optimization, robust monitoring strategies, and effective communication to improve public acceptance, while demonstrating how ozonation can address key challenges in reclaimed water treatment and support sustainable water management practices.