The impact of various ozone pretreatment doses on the performance of endogenous microbial communities for the remediation of oils sands process-affected water

  • Author / Creator
    Dong, Tao
  • In this study, the effects of different ozone pretreatment doses on the performance of endogenous microbial populations in degrading naphthenic acids (Nash and Traver) for the treatment of oil sands process-affected water (OSPW) were evaluated. The results showed that ozonation enhanced the biodegradability of OSPW and the maximum COD removal through biodegradation which occurred at utilized ozone dose of 50 mg/L. After pretreatment with the highest utilized ozone dose of 200 mg/L and bioreactor operation for 73 days, the batch bioreactor removed more than 80% of the chemical oxygen demand (COD), it also removed greater than 95% of the acid extractable fraction (AEF) from the OSPW. High-resolution mass spectrometry analysis showed complete degradation of NAs with specific degrees of cyclization (Z= -2 and -4) after combined treatment of ozonation and biodegradation. Furthermore, with increasing the utilized ozone, the total bacterial number increased while specific bacterial strains such as Sphingomonadaceaeand Azoarcus have shown to improve the bioreactor performance. At high pretreatment utilized doses of ozone (116 and 200 mg/L), the biodegradation completely eliminated the acute toxicity of OSPW towards Vibrio fischeri (IC20> 100% v/v). In summary, increasing the ozone dose used for pretreatment of OSPW showed clear benefits regarding the removal of organic compounds, the growth of bacteria, and the reduction of toxicity.

  • Subjects / Keywords
  • Graduation date
    Fall 2015
  • Type of Item
  • Degree
    Master of Science
  • DOI
  • License
    This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.