Insight into the selective accumulation of anammox bacteria based on detoxification mechanism induced by ambient concentration enrofloxacin

Anaerobic ammonium oxidation (anammox) has become the most promising biotechnology to achieve both efficient nitrogen removal and carbon neutrality in wastewater treatment, however, the fate of antibiotic wastewater on the ambient concentration in anammox process is still absent. Here, two up-flow anaerobic sludge blanket (UASB) reactors fed with synthetic wastewater were operated without (UACK) and with (UBENR) the enrofloxacin (ENR) to reveal the influence of ambient concentration antibiotic (ranging from 0.2 to 1 mg L-1) on anammox consortia as long-term reactors operation. The characteristics of anammox sludge, functional community structure, and potential metabolic pathway were investigated.