Effects of Enrofloxacin on Nutrient Removal by a Floating Treatment Wetland Planted with Iris pseudacorus: Response and Resilience of Rhizosphere Microbial Communities

Constructed wetlands (CWs), including floating treatment (FTWs), possess great potential for treating excessive nutrients in surface waters, where, however, the ubiquitous presence of antibiotics, e.g., enrofloxacin (ENR), is threatening performance CWs. In developing a more efficient and resilient system, we explored responses FTW to ENR, using tank 1, repeatedly exposed 2 as control. Plant growth nutrient uptake were remarkably enhanced similar phosphorus removal rates (86~89% total added P) obtained both tanks over experimental period. Contrarily, ENR apparently inhibited N by 1 (35.1%), compared 40.4% 2. As rapidly decreased an average 71.6% within week after each addition, took only 4 weeks adapt return state that This might be because recovery microbial communities, particularly denitrifying antibiotic-resistance genes containing bacteria, such Actinobacteria, Patescibacteria, Acidovorax Pseudomonas. After three exposures six weeks, no significant differences communities found between tanks, suggesting resilience ENR.