Effect of sulfide concentration on autotrophic denitrification from nitrate and nitrite in vertical fixed-bed reactors

► Post treatment of effluents from anaerobic reactors treating domestic sewage. ► Comparison between autotrophic denitrification from nitrate and nitrite. ► Effect of sulfide concentration on sulfide-oxidizing autotrophic denitrification. ► Elemental sulfur as the main intermediate during sulfide oxidation. ► Nitrite is more readily used by microorganisms due to its higher reactivity.