Rethinking tertiary clarifiers: untapped potential for microbial and genetic pollution control in wastewater treatment
This study proposes an overlooked yet promising alternative to classical disinfection used in wastewater treatment plants (WWTPs) to control fecal bacteria and, indirectly, antibiotic resistance genes (ARGs): tertiary clarifiers. Applying 16S amplicon and shotgun sequencing to samples from three WWTPs with varying inflow characteristics, we demonstrated that tertiary clarifiers actively shape microbial communities, reducing bacterial abundance while maintaining community richness. Tertiary treatment also decreased total ARG abundance.