title: Pilot-scale nitrogen removal from leachate by ex situ nitrification and in situ denitrification in a landfill bioreactor.
abstract: A combined process consisting of ex situ nitrification and in situ denitrification in landfill refuse was studied in pilot scale for nitrogen removal from municipal landfill leachate. The results showed that above 80% of partial nitrification ratio and an average COD loading rate of 1.50 kg m(-3) d(-1) were steadily maintained under DO concentrations of 1.0-1.7 mg L(-1) in the aerobic reactor. Quantitative PCR results indicated that nitrite-oxidizing bacteria being sensitive to DO fluctuations lead to partial nitrification when free ammonia inhibition was weak. Nitrified landfill leachate could be denitrified in the landfill bioreactor with maximum total oxidizing nitrogen removal rate of 67.2 g N t(-1) TSwaste d(-1). Clone and sequencing analysis of denitrifying bacterial nirS gene inferred that heterotrophic denitrifier Azoarcus tolulyticu was the primary nitrogen converter in the landfill bioreactor. The obtained results will provide valuable information for optimizing the design and operation of a landfill bioreactor.
authors.affiliation: Institute of Environmental Science and Technology, Zhejiang University, Hangzhou 310058, China.
authors.forename: Faqian
authors.initials: F
authors.lastname: Sun
authors.affiliation: Institute of Environmental Science and Technology, Zhejiang University, Hangzhou 310058, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Sun
authors.affiliation: Ningda Inspection and Technology Co. Ltd., Hangzhou 310004, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Li
authors.affiliation: Institute of Environmental Science and Technology, Zhejiang University, Hangzhou 310058, China.
authors.forename: Xiaoya
authors.initials: X
authors.lastname: Deng
authors.affiliation: Institute of Environmental Science and Technology, Zhejiang University, Hangzhou 310058, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Hu
authors.affiliation: Institute of Environmental Science and Technology, Zhejiang University, Hangzhou 310058, China. Electronic address: weixiang@zju.edu.cn.
authors.forename: Weixiang
authors.initials: W
authors.lastname: Wu
mesh_terms: D000641:Ammonia; D001419:Bacteria / Q000235:genetics; D019149:Bioreactors / Q000382:microbiology*; D058440:Denitrification; D058465:Nitrification; D009573:Nitrites; D009584:Nitrogen / Q000302:isolation & purification*; D010865:Pilot Projects; D012037:Refuse Disposal; D064091:Waste Disposal Facilities; D014874:Water Pollutants, Chemical
chemical_list: D009573:Nitrites; D014874:Water Pollutants, Chemical; D000641:Ammonia; D009584:Nitrogen
keywords: Denitrification; Landfill leachate; Landfill refuse; Nitrification; Real-time PCR