Research progress on nitrite accumulation in sulfur-based autotrophic denitrification process

Abstract

Anaerobic ammonia oxidation (Anammox) is regarded as one of the most cost-effective wastewater biological nitrogen removal technologies due to no need for external organics, low sludge production,and low operating costs. However, nitrite (NO2--N) accumulation is an necessary prerequisite for Anammox. Researches have shown that partial nitrification has the difficulty of stably suppressing the activity of nitrite oxidizing bacteria, while heterotrophic partial denitrification has some issues such as additional carbon source and high carbon emissions. In recent years, sulfur-based partial autotrophic denitrification(SPAD) as a new method of reducing NO3--N to NO2--N has attracted extensive attentions because of no need for external organic carbons, low economic costs, and environmental friendliness. Therefore, the study comprehensively reviewed the process principle, NO2--N accumulation influencing factors, by-products of denitrification process, key bacterial and functional genes and systematically summarized the efficiency of SPAD. Finally, the economic performance of different types of SPAD was compared and the future research prospect was proposed.

Keywords

• sulfur-based partial autotrophic denitrification
• nitrite accumulation
• electronic donors