Sulfur-oxidizing autotrophic and mixotrophic denitrification processes for drinking water treatment: Elimination of excess sulfate production and alkalinity requirement

► Elemental sulfur can serve as electron donor for drinking water denitrification. ► Mixotrophic denitrification is faster than sulfur-based denitrification. ► Mixotrophic denitrification process decreases sulfate production. ► Sulfur-based autotrophic process needs external alkalinity supplementation. ► Mixotrophic denitrification can eliminate the need of alkalinity supplementation.