Evaluation of the Efficiency of Ozone Nanobubbles in Wastewater Treatment

• Grant number: 24/23386-6
• Support Opportunities: Regular Research Grants
• Start date: May 01, 2025
• End date: April 30, 2028
• Field of knowledge: Engineering - Sanitary Engineering - Water Supply and Wastewater Treatment
• Principal Investigator: Renato Falcão Dantas
• Grantee: Renato Falcão Dantas
• Host Institution: Faculdade de Tecnologia (FT). Universidade Estadual de Campinas (UNICAMP). Limeira , SP, Brazil
• Associated researchers: Dânia Elisa Christofoletti Mazzeo Morales ; Joyce Cristale ; Patricia Prediger

Abstract

Ozonation has become a prominent technique among advanced wastewater treatment methods due to its ability to remove various types of organic contaminants and to disinfect wastewater. This prominence is evident in the growing number of water and wastewater treatment plants worldwide that use ozonation units. However, the use of ozone for wastewater treatment faces some limitations, such as its short residence time in solution, typically lasting only a few minutes. An innovative and promising solution to enhance ozone utilization across various applications is the use of ozone nanobubbles. The production of these bubbles increases the transfer of ozone from the gas phase to the liquid phase, where it acts. Another important feature of nanobubbles is their relative stability in solution, allowing ozone to remain active for days or even weeks. The gradual collapse of nanobubbles over time also promotes the formation of reactive radicals, which assist ozone in treating wastewater. Nonetheless, many gaps remain in understanding this technology, such as (i) understanding ozone decomposition and radical formation, (ii) validating ozone measurement methodologies in the presence of nanobubbles, (iii) accurately assessing the contribution of nanobubbles in the presence of microbubbles, and (iv) conducting cost studies to confirm whether the energy used in bubble production is economically viable, among others. This project is pioneering in proposing an understanding of the basic aspects of this technology as well as in evaluating its effectiveness in eliminating micropollutants and disinfecting wastewater, with a focus on effluents from wastewater treatment plants (WWTPs). The data produced by this project will undoubtedly be useful to scientists and companies using ozone for water and wastewater treatment. (AU)