Mitigation of N2O emission from the nitrite shortcut process

• Main Author: Poh, Leong Soon
• Other Authors: Liu Yu
• Format: Thesis-Doctor of Philosophy
• Language: English
• Published: Nanyang Technological University 2016
• Subjects: DRNTU::Engineering::Environmental engineering::Water treatment; DRNTU::Engineering::Environmental engineering::Environmental pollution
• Online Access: http://hdl.handle.net/10356/68952
• Institution: Nanyang Technological University

The nitrite shortcut is a biological ammonium-nitrogen removal process which has lower requirements for energy and chemical reagents compared to conventional nitrification and denitrification. However, N₂O emission from this process is higher than traditional methods. This thesis looks into the establishment of nitrite shortcut SBRs for municipal wastewater treatment and N₂O emission from the process. It was found that control of SRT and aeration supply were effective in quick establishment of the nitrite shortcut process. Influent inorganic carbon concentration is an important requirement for the enrichment of ammonia oxidizing bacteria. During aerobic nitritation, N₂O emission was found to be affected by the ammonium loading rate (ALR). The N₂O emission factor increased 3 folds when ammonium accumulated at high ALR. During denitrification, temperature was found to affect N₂O accumulation and emission. At higher temperature, imbalanced denitrification rates caused N₂O accumulation and lower solubility at higher temperatures caused higher N₂O emission.