The impacts of ozonation on oil sands process-affected water biodegradability and biofilm formation characteristics in bioreactors

► Ozonation on biofilm formation and organic compounds removal in OSPW was tested. ► Two types of biofilm substrate materials and two types of wastewater were tested. ► The combined ozonation and biodegradation process effectively removed COD and TAO. ► UPLC/HRMS analysis showed that biodegradation of NA was dependent on the Z number. ► PVC supported a thicker biofilm and a greater microbial community diversity than PE.