Microbubble-Enhanced Recovery of Residual Bitumen from the Tailings of Oil Sands Extraction in a Laboratory-Scale Pipeline

The recovery of valuables from industrial wastewater prior to release to the environment is indispensable to comply with ever pressing economic and environmental imperatives. In this work, microbubbles generated by a 3D-printed venturi tube were applied in a laboratory-scale pipeline loop to evaluate the recovery performance of residual bitumen from oil sands tailings. The addition of microbubbles provided a sufficient surface area in tailings media to capture effectively bitumen droplets. Our results showed that the injection of microbubbles upstream substantially enhanced the separation kinetics on account of providing sufficient time for the bitumen–bubble interaction prior to the collection trough. It was found that ca. 50% of residual bitumen can be recovered using the upstream injection of microbubbles for a duration of a 30 min circulation of tailings in the pipeline loop. Such enhancement in bitumen recovery revealed a high potency of microbubbles in collecting more bitumen from tailings in comparison with ca. 10% recovery achieved through flotation size bubbles injected by the needle. The findings of the current study suggest a new potential solution for intensification of the bitumen recovery process from industrial wastewater.