Application of electrochemical technology for removing petroleum hydrocarbons from produced water using a DSA-type anode at different flow rates

The anodic oxidation of organic pollutants from produced water generated by petroleum exploration of the Petrobras plant-Brazil was studied using a RuO2–TiO2–SnO2 electrode. Under galvanostatic conditions (j = 89 mA cm−2), it was observed that the performance of the electrode material is influenced by flow rate as it was shown by GC analysis. It was found that the organic pollutants degradation, using different flow rates (0.25, 0.5, 0.8 and 1.3 dm−3 h), achieved distinct removal efficiencies (98%, 97%, 95% and 84% were achieved, respectively). Importantly, under the same conditions, RuO2–TiO2–SnO2 showed poor degradation of phenol and ethyl benzene: 20–47% (at 0.25, 0.8 and 1.3 dm−3 h) and 17–47% (at 0.25, 0.5, 0.8 dm−3 h), respectively. Complete elimination of pollutants was obtained after 0.5–2.5 h of electrolysis. These data were discussed based on the energy and cost requirements for removing organic pollutants from produced water.