Research progress of partial denitrification in wastewater treatment: Mechanisms, influential factors, and technology

Abstract

Partial denitrification(PD) can reduce nitrate to nitrite, and is an important way to provide substrates steadily in anaerobic ammonia oxidization(ANAMMOX) reaction. PD has great potential in energy-efficient biological nitrogen removal of wastewater, and has become a research hotspot in recent years. In this work,the mechanism of PD was introduced from the aspects of its biological process and functional microorganisms. Then the key factors affecting the PD process, such as carbon source, carbon-nitrogen ratio, environmental conditions, and heavy metals, etc. were summarized. Moreover, the research on PD in biological nitrogen removal process in recent years was also reviewed. Finally, the problems existing in the current research and the aspects for further research of PD were discussed. This work is expected to provide theoretical supports for the development and application of PD in biological nitrogen removal of wastewater.

Keywords

• partial denitrification
• biological denitrification
• nitrite accumulation
• anammox