Applied Microbiology and Biotechnology, Vol.103, No.18, 7459-7466, 2019
New direction in biological nitrogen removal from industrial nitrate wastewater via anammox
Anaerobic ammonium oxidation (anammox) is an important scientific discovery in the field of wastewater treatment. This process is a sustainable option in nitrogen removal due to its energy-efficient and cost-effective advantage. Great effort has been made recently to remove ammonium from industrial and municipal wastewater via the anammox process with a preceding partial nitrification (PN) converting part of NH4+ to NO2-. Anammox process is seldom involved in the nitrate removal. Nitrate (NO3-), one of the main nitrogen compounds produced from various industries, is typically converted to nitrogen gas via denitrification process where a large amount of carbon source is consumed. Within this context, we reviewed the current technologies for high-strength nitrate wastewater treatment. It is found that nitrite accumulation often occurs during nitrate reduction, and its accumulating level would be increased at certain conditions (i.e., low C/N ratio and high pH). Hence, this provides a great opportunity to employ the anammox process to further convert nitrite in a more sustainable way. In this review, we highlight a new approach for industrial nitrate wastewater treatment via partial denitrification coupled with anammox process (PD-A). We also discuss the conditions to achieve successful PD-A process, economic and environmental benefits, and potential challenges as well as the future perspectives in practical application.
Keywords:Anaerobic ammonium oxidizing (anammox);Partial denitrification (PD);Nitrite accumulation;Industrial nitrate wastewater;Biological nitrogen removal