Behavior analysis of a porous bed electrochemical reactor the treatment of petrochemical industry wastewater contaminated by hydrogen sulfide (H2S)

• Apply electrochemical oxidation process to neutralize H2S from industrial effluents.
• The potentiostatic control and the conversion of H2S into sulfate and thiosulfate species.
• The results indicated mixed control process and a good conversion rate.

The concern for the removal of contaminants, such as hydrogen sulfide (H2S), during crude oil processing has been intensified. Sulfur compounds, such as dissociated H2S, are detected in the effluents of process gas condensation and streams of acid water. The objective of this study is to apply electrochemical oxidation to neutralize H2S in industrial effluents. Tests were performed in a porous bed electrochemical reactor, which was composed of reticulated vitreous carbon. The oxidation process is direct and potentiostatically controlled, and the dissociated sulfide was oxidized to sulfate and/or thiosulfate, main product of the reaction. Figures of merit were constructed to evaluate the performance of electrochemical reactor under different hydrodynamic conditions, by varying the flow rate, and overpotential, by varying the distance between the electrodes in the reactor. The figures of merit indicated that the best condition for the formation of thiosulfate occurred at the lowest flow rate used, 1.05 L h−1 and at a greater distance between the electrodes, 60 mm.