Document Type : Review Paper


Department of Petroleum Technology, University of Technology, Baghdad-Iraq


Petroleum is a vital source of energy for most human activities. The growth of the oil and gas sector is associated with releasing a significant amount of produced water (PW) from onshore and offshore fields. Thus, undesirable toxic pollutants in produced water have become a major concern for those concerned with environmental issues. Therefore, interest in recycling and beneficial reuse of pollutants has increased due to large amounts of PW. In general, various physical and chemical technologies and bio-treatments for PW or combined between them are applied. Bio-treatment is preferred due to its efficiency and eco-friendly compared with other PW treatments. To clarify the prospective role of PW bio-treatments, this review highlights the main bio-treatment technologies in aerobic and anaerobic conditions to reduce salinity, organic components, and toxicity from PW. Also, challenges of environmental factors for PW and future research directions are included. Activated sludge is an essential part of aerobic bio-treatments of polluted water as inoculum rich in microbial cells that can degrade pollutants. Membrane bioreactors (MBR), fluidized bed bioreactors (FBBs), aerated biological filter (BAF), and aeration lagoons are also reviewed. Moreover, bio-treatments are extended to include anaerobic conditions. Furthermore, bio-treatment techniques can treat organic compounds of wastewater, especially with low oil concentrations and poor solubility that cannot be treated with conventional treatments. 

Graphical Abstract


  • It has become essential to develop an appropriate management strategy for PW treatment to avoid environmental impact.
  • Microbial biodegradation is known to be effective bioremediation for the disposal of various types of compounds, such as organic in PW
  • Aerobic treatment is fast and efficient for the elimination of degradable pollutants.
  • Anaerobic treatment is a preferential treatment used to provide clean energy from organic waste


Main Subjects

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