Decomposition of ammonia and hydrogen sulfide in simulated sludge drying waste gas by a novel non-thermal plasma.

To efficiently clean NH3 and H2S contained in municipal sewage sludge drying waste gas, experiments were conducted with a novel gliding arc discharge plasma reactor. Important parameters including applied voltage and gas velocity which can strongly influence the removal efficiency, energy cost and by-products yields were investigated. Maximum removal efficiencies were all obtained at the applied voltage of 11 kV and gas velocity of 4.72 m s−1. When NH3 and H2S were treated together, the total energy cost decreased by 38%. NO and SO2 were observed as main decomposition by-products, and the presence of NH3 may inhibit the production of SO2 whose yield decreased from 223.8 to 27.8 mg m−3. Tests performed on lab scale reactor showed that gliding arc discharge is efficient in decreasing the NH3 and H2S concentrations, and experiments will also be conducted on a larger scale reactor in the future.