Enhanced removal of emerging micropollutants by applying microaeration to an anaerobic reactor

Abstract

The present paper aimed to evaluate the impact of microaeration on both the removal performance of some emerging micropollutants (pharmaceuticals, hormones, and bisphenol A) and the microbial community structure of an anaerobic reactor treating synthetic wastewater. Under anaerobic conditions, the removal efficiencies of the micropollutants were very low (< 10%). However, the microaeration (1.0 mL air·min-1 at 27 °C and 1 atm, equivalent to a QAIR/QINF ratio of 0.1) expressively improved the removal efficiencies of all compounds (> 50%). Therefore, supplementing anaerobic reactors with low amounts of oxygen seems to be an interesting strategy to enhance the removal of the micropollutants tested. However, further studies should be carried out with other compounds in order to evaluate the wide applicability of microaeration to different classes of micropollutants in lab- and full-scale treatment systems. Concerning the microbiota structure, both bacterial and archaeal communities were not compromised by the different operational conditions and preserved their functional organization with high richness during the whole experiment.