posted on 2024-01-01, 18:03authored byRenato F. Dantas, Joyce Cristale, Cristian Gómez-Canela, Natalia Rodríguez, Ivna Seabra, Jacqueline Malvestiti, Silvia Lacorte
Despite the well-known efficiency of ozonation in treating
secondary
effluents and its increasing global application, the removal of micropollutants
is still a matter of concern. Ozone installations for tertiary treatment
are typically installed with specific objectives such as disinfection,
color and odor removal, and micropollutant removal, among others.
However, due to factors such as the absence of legislation in many
countries, complexity, and cost of analysis, for example, the accurate
assessment of micropollutant removal during ozonation is limited to
a few legislated compounds. This study aimed to contribute to the
evaluation of pharmaceutical removal by introducing an index that
correlates the inactivation of common bacteria widely used as disinfection
indicators (total coliforms and Escherichia coli) with the removal of micropollutants during ozonation of secondary
effluents. The developed index, named Microlog, was tested in three
different wastewater treatment plants and compared with existing literature
data. Strong correlations were observed between the log10 reduction of bacteria and the percentage of specific micropollutant
removal, regardless of the effluent quality. The Microlog concept
can serve as an additional tool for assessing the final removal of
micropollutants when the ozone disinfection of the wastewater treatment
plant effluent is measured.