New insights on the combined removal of antibiotics and ARGs in urban wastewater through the use of two configurations of vertical subsurface flow constructed wetlands

The occurrence and removal of 49 antibiotics 11 selected antibiotic resistance genes (ARGs) were investigated in 2 vertical subsurface flow (VF) constructed wetlands (1.5 m2 each): an unsaturated (UVF) unit a partially saturated (SVF) (0.35 m out 0.8 m) operating parallel treating urban wastewater. Thirteen detected influent wastewater, 6 which present all samples. SVF showed statistical significance on the 4 compounds (namely ciprofloxacin, ofloxacin, pipemidic acid azithromycin), suggesting that wider range pH and/or redox conditions this configuration might promote microbial degradation some antibiotics. In contrast, concentration latter (except acid) also clindamycin was higher effluent than UVF. Five ARGs sul1 sul2, blaTEM, ermB qnrS. All them biofilm both wetlands, except Average rates no differences between wetland units, ranged 46 97% for sul1, 33 9 99% ermB, 18 qnrS 98% blaTEM.