Large quantities of the oil sands process affected water (OSPW) are generated from the bitumen extraction process. The OSPW is contained in lake-sizes ponds waiting for a treatment before to be reclaimed. One of the suitable treatments are the ozonation, its overall effect on the OSPW have been reported as effective. Nevertheless, there are few reports on the details of this process, which could explain how this system behaves and how it could be controlled in the most efficient way. On this research, OSPW was ozonated in various conditions to find the effects of the molecular ozone, carbonate and OH radicals on the degradation of the NAs and the rest of the organic fraction. The results suggest that molecular ozone contribute to the overall NAs degradation process, as a result the NAs may have some unsaturations and carbonate may control the degradation process in great extent.