Anaerobic Ammonium Oxidation Process in an Upflow Anaerobic Sludge Blanket Reactor with Granular Sludge Selected from an Anaerobic Digestor

• Published in: Biotechnology and bioprocess engineering Vol. 11; no. 3; pp. 199 - 204
• Main Authors: Tran, Hung-Thuan, Park, Young-Joo, Cho, Mi-Kyeoung, Kim, Dong-Jin, Ahn, Dae-Hee
• Format: Journal Article
• Language: Korean
• Published: 한국생물공학회 01-06-2006
• Subjects: 생물공학; ammonium; UASB reactor; nitrite; anaerobic ammonium oxidation (anammox); granular sludge; nitrogen removal
• ISSN: 1226-8372; 1976-3816

The purpose of this work was to evaluate the development of the anammox process by the use of granular sludge selected from a digestion reactor as a potential seed source in a lab-scale UASB (upflow anaerobic sludge blanket) reactor system. The reactor was operated for approximately 11 months and was fed by synthetic wastewater. After 200 days of feeding with $NH_4^+\;and\;NO_2^-$ as the main substrates, the biomass showed steady signs of ammonium consumption, resulting in over 60% of ammonium nitrogen removal. This report aims to present the results and to more closely examine what occurs after the onset of anammox activity, while the previous work described the start-up experiment and the presence of anammox bacteria in the enriched community using the fluorescence in situ hybridization (FISH) technique. By the last month of operation, the consumed $NO_2^--N/NH_4^+-N$ ratio in the UASB reactor was close to 1.32, the stoichiometric ratio of the anammox reaction. The obtained results from the influent-shutdown test suggested that nitrite concentration would be one key parameter that promotes the anammox reaction during the start-up enrichment of anammox bacteria from granular sludge. During the study period, the sludge color gradually changed from black to red-brownish.