title: Nitrification of high-strength ammonium landfill leachate with microbial community analysis using fluorescence in situ hybridization (FISH).
abstract: Nitrification of mature sanitary landfill leachate with high-strength of N-NH(4) + (1080-2350 mg L(-1)) was performed in a 10 L continuous nitrification activated sludge reactor. The nitrification system was acclimatized with synthetic leachate during feed batch operation to avoid substrate inhibition before being fed with actual mature leachate. Successful nitrification was achieved with an approximately complete ammonium removal (99%) and 96% of N-NH(4) + conversion to N-NO(-) (3) . The maximum volumetric and specific nitrification rates obtained were 2.56 kg N-NH(4) (+) m(-3) day(-1) and 0.23 g N-NH(4) ( +) g(-1) volatile suspended solid (VSS) day(-1), respectively, at hydraulic retention time (HRT) of 12.7 h and solid retention time of 50 days. Incomplete nitrification was encountered when operating at a higher nitrogen loading rate of 3.14 kg N-NH(4) (+) m(-3) day(-1). The substrate overloading and nitrifiers competition with heterotrophs were believed to trigger the incomplete nitrification. Fluorescence in situ hybridization (FISH) results supported the syntrophic association between the ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria. FISH results also revealed the heterotrophs as the dominant and disintegration of some AOB cell aggregates into single cells which further supported the incomplete nitrification phenomenon.
authors: Department of Biological Functions and Engineering, Graduate School of Life Science and Systems Engineering, Kyushu Institute of Technology, Kitakyushu, Fukuoka, Japan. norjan@fsmt.upsi.edu.my
authors: Norjan
authors: N
authors: Yusof
authors: Mohd Ali
authors: MA
authors: Hassan
authors: Phang Lai
authors: PL
authors: Yee
authors: Meisam
authors: M
authors: Tabatabaei
authors: Mohd Ridzuan
authors: MR
authors: Othman
authors: Masatsugu
authors: M
authors: Mori
authors: Minato
authors: M
authors: Wakisaka
authors: Kenji
authors: K
authors: Sakai
authors: Yoshihito
authors: Y
authors: Shirai
mesh_terms: D001419:Bacteria / Q000145:classification / Q000302:isolation & purification*; D044822:Biodiversity; D017404:In Situ Hybridization, Fluorescence; D008296:Malaysia; D058465:Nitrification; D000644:Quaternary Ammonium Compounds / Q000378:metabolism*; D012988:Soil Microbiology; D014865:Waste Disposal, Fluid / Q000379:methods; D014874:Water Pollutants, Chemical / Q000032:analysis*; D018508:Water Purification / Q000379:methods*
chemical_list: D000644:Quaternary Ammonium Compounds; D014874:Water Pollutants, Chemical