Improving the quality and efficiency of biological nitrogen removal from domestic wastewater: Current situation and prospects

Abstract

With the improvement of national and local sewage discharge standards, the upgrading and retrofitting of existing wastewater treatment systems become a major challenging task for wastewater treatment plants (WWTPs). Specially, meeting the concentration limits for total nitrogen in the effluent is the important and difficult point. Thus, under the "carbon peaking and carbon neutrality" goal, the technological paths for improving the quality and efficiency of biological nitrogen removal (BNR) from low carbon to nitrogen domestic wastewater are elaborated in this review, and future study directions are also suggested. Firstly, the traditional paradigms for enhancing BNR are systematically reviewed, primarily including deep excavation of the BNR potential of the original biological treatment process and incorporation with the denitrification biofilter advanced treatment process. Secondly, the research progress and application prospect of low-carbon autotrophic BNR processes, such as anaerobic ammonium oxidation, sulfur-driven autotrophic denitrification, and nitrate-dependent ferrous oxidation, are comprehensively introduced, which can provide the theoretical basis and technical support for the establishment of environmentally friendly and efficient autotrophic BNR systems or synergistic heterotrophic-autotrophic advanced BNR systems. Finally, future directions and trends of BNR from domestic wastewater are proposed. The integration of biotechnology, material technology, and information technology can drive technological change and innovation in the wastewater BNR field. This review aims to provide guidance for the synergistic effect of pollution and carbon reduction of BNR from domestic wastewater.

Keywords

• domestic wastewater
• upgrading and retrofitting
• biological nitrogen removal
• autotrophic nitrogen removal
• anaerobic ammonium oxidation