Effect of polytetrafluoroethylene nanoplastics on combined inhibition of ciprofloxacin and bivalent copper on nitrogen removal, sludge activity and microbial community in sequencing batch reactor

•PTFE-NPs weaken the Cu(II) and CIP antagonism on sludge activities.•Nitrifier was more alive to Cu(II) and CIP than denitrifier with or without PTFE-NPs.•Adsorption of CIP and Cu(II) by PTFE-NPs was synergistic.•PN level in EPS was decreased by PTFE-NPs at mixed Cu(II)/CIP.•PTFE-NPs abated the binding of functional groups in PN and PS to mixed Cu(II)/CIP.