title: Denitrification capacity of a landfilled refuse in response to the variations of COD/NO3--N in the injected leachate.
abstract: Effects of different chemical oxygen demand (COD) to nitrate concentration ratios in the injected leachate on the denitrification capacity of landfilled municipal solid waste were evaluated. Results showed that the 6-year-old refuse possessed high denitrification capacity. The nitrate reduction rate increased with the increasing COD concentration in the injected leachate. When the initial COD concentration increased to 6500 mg l(-1), nitrate reduction rate could reach up to 6.85 mg NO3--N l(-1) h(-1). At the initial biodegradable COD/NO3--N ratio lower than the stoichiometric ratio of heterotrophic denitrification, autotrophic bacteria was the dominant microbial communities for denitrification. With the increase of COD/NO3--N ratio, the primary functional denitrifier would shift from autotrophic Thiobacillus denitrificans to heterotrophic Azoarcus tolulyticus. These results suggested that the initial biodegradable COD/NO3--N ratio in the injected leachate should be adjusted to higher than 6.0 for rapid in situ denitrification of 500 mg NO3--Nl(-1).
authors.affiliation: Ministry of Agriculture Key Laboratory of Non-point Source Pollution Control, Institute of Environmental Science and Technology, Zhejiang University, Hangzhou 310058, PR China.
authors.forename: Faqian
authors.initials: F
authors.lastname: Sun
authors.forename: Songwei
authors.initials: S
authors.lastname: Wu
authors.forename: Jingjing
authors.initials: J
authors.lastname: Liu
authors.forename: Bo
authors.initials: B
authors.lastname: Li
authors.forename: Yingxu
authors.initials: Y
authors.lastname: Chen
authors.forename: Weixiang
authors.initials: W
authors.lastname: Wu
mesh_terms: D000641:Ammonia / Q000032:analysis; D001419:Bacteria / Q000378:metabolism; D001673:Biodegradation, Environmental; D057919:Biological Oxygen Demand Analysis; D019149:Bioreactors / Q000382:microbiology; D058440:Denitrification; D005798:Genes, Bacterial / Q000235:genetics; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D009566:Nitrates / Q000032:analysis*; D009573:Nitrites / Q000032:analysis; D009584:Nitrogen / Q000032:analysis*; D010802:Phylogeny; D012037:Refuse Disposal; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*
chemical_list: D009566:Nitrates; D009573:Nitrites; D014874:Water Pollutants, Chemical; D000641:Ammonia; D009584:Nitrogen