title: Assessment of partial nitrification reactor performance through microbial population shift using quinone profile, FISH and SEM.
abstract: In engineered systems, biological nitrogen removal through partial nitrification to nitrite is of great interest. Accordingly, effect of operating parameters such as pH, DO and temperature on the accumulation of ammonia-oxidizers was investigated. pH of 8, DO of 0.3-0.5mg/l and temperature of 35 degrees C yielded a ratio of 0.9-1.5 of NO(2)N:NH(4)N in the effluent suitable as a feed for Anammox reactor. Microbial population shift during start-up was assessed using quinone profile, SEM and FISH. UQ-8 in the biomass, which is the predominant quinone in ammonia-oxidizers, increased from 24.8% on Day 1 to 61.2% on Day 136. Fluorescence in situ hybridization analysis in the reactor showed that ammonia-oxidizing bacteria gradually outcompeted other bacteria and was the dominant population. The morphology and inner structure of the granular sludge was observed using SEM and the photographs indicated that the aerobic granular sludge showed a shift towards spherical and small rod-shaped clusters.
authors.affiliation: Environmental Engineering and Management, Asian Institute of Technology, P.O. Box 4, Klong Luang, Pathumthani 12120, Thailand. Banashri.Sinha@ait.ac.th
authors.forename: B
authors.initials: B
authors.lastname: Sinha
authors.forename: A P
authors.initials: AP
authors.lastname: Annachhatre
mesh_terms: D000641:Ammonia / Q000378:metabolism; D001419:Bacteria / Q000378:metabolism*; D019149:Bioreactors / Q000592:standards*; D006863:Hydrogen-Ion Concentration; D017404:In Situ Hybridization, Fluorescence; D008855:Microscopy, Electron, Scanning; D009573:Nitrites / Q000378:metabolism; D009584:Nitrogen / Q000378:metabolism*; D010100:Oxygen / Q000737:chemistry; D011809:Quinones / Q000378:metabolism*; D012722:Sewage / Q000032:analysis / Q000737:chemistry*; D013696:Temperature; D013997:Time Factors; D014874:Water Pollutants, Chemical
chemical_list: D009573:Nitrites; D011809:Quinones; D012722:Sewage; D014874:Water Pollutants, Chemical; D000641:Ammonia; D009584:Nitrogen; D010100:Oxygen