Degradation of dissolved sulfide in water using multi-hole dielectric barrier discharge

Biogas obtained from livestock manure is used as fuel for solid oxide fuel cells. Although H₂S is a typical biogas, it is a fatal disadvantage for fuel-cell power generation and, thus, must be removed. In this study, we proposed an effective method for sulfide removal from water using a multi-hole dielectric barrier discharge (DBD) system. In this system, active species, such as ozone, ultraviolet rays, hydroxyl radicals, and hydrogen peroxide, were simultaneously generated. Under optimal conditions, dissolved sulfide (initial concentration: 120 mg/L) was completely degraded within 10 min in air plasma and 6 min in oxygen plasma. Changes in the physical properties of the sulfide-treated water were confirmed by measuring the pH, oxidation-reduction potential, and dissolved oxygen. Results of the by-product analysis showed that sulfide was converted into sulfate by reacting with a large amount of ozone, and the active species were emitted from the multi-hole DBD system. In summary, multi-hole DBD technology has demonstrated merit as a water-contaminant purification technology and for the removal of dissolved sulfide.