Total petroleum hydrocarbon degradation by hybrid electrobiochemical reactor in oilfield produced water

• The hybrid electrolytic biological cell was used for degradation of oilfield produced water.
• Decomposition of Total Petroleum Hydrocarbon with or without the biofilter.
• High saline water with the high chloride and sulfate ions content treatment.
• The removal of electrochemical by-products is a phase change technique that requires the maintenance the biofilm on the filter media, which is sensitive and a complex operation.
• Biofilter is efficient for the degradation of PW bye products, the critical drawback to their utility in full-scale operations is high TDS water content and detention time of treatment.

The crude oil drilling and extraction operations are aimed to maximize the production may be counterbalanced by the huge production of contaminated produced water (PW). PW is conventionally treated through different physical, chemical, and biological technologies. The efficiency of suggested hybrid electrobiochemical (EBC) methods for the simultaneous removal of total petroleum hydrocarbon (TPH) and sulfate from PW generated by petroleum industry is studied. Also, the factors that affect the stability of PW quality are investigated. The results indicated that the effect of biological treatment is very important to keep control of the electrochemical by-products and more TPH removal in the EBC system. The maximum TPH and sulfate removal efficiency was achieved 75% and 25.3%, respectively when the detention time was about 5.1 min and the energy consumption was 32.6 mA/cm2. However, a slight increasing in total bacterial count was observed when the EBC compact unit worked at a flow rate of average 20 L/h. Pseudo steady state was achieved after 30 min of current application in the solution. Also, the results of the study indicate that when the current intensity was increased above optimum level, no significant results occurred due to the release of gases.