Electrochemical removal of hydrogen sulfide from swine manure

Abstract Hydrogen sulfide (H 2 S) produced in swine manure storage is a safety hazard to both humans and animals. An electrochemical treatment method based on low carbon steel electrodes was developed to reduce aqueous sulfide and emitted H 2 S concentration from manure storage. At the selected condition (applied voltage of 0.7 V, immersed electrode surface area of 19 cm 2 /L, initial sulfide concentration around 6 mM, and operating temperature of 19 °C), the process achieved an average sulfide removal rate of 0.97 mg S 2− /(cm 2 ·day) for the zero order kinetics model, and a rate coefficient of 0.267/day for the first order kinetics model. The electrical charge consumption was 5.26 C/mg S 2− . With the removal of over 90% (95% maximum) of sulfide and H 2 S, the risk of massive release of H 2 S can be significantly reduced. The installation of this treatment technology may reduce the risk of manure pump-out in terms of H 2 S over-exposure and may be applied in similar circumstances where H 2 S poses threats to health and life.