title: [Effect of injected leachate C/N ratio on the denitrification of a bioreactor filled with landfilled refuse].
abstract: The denitrification capacity of a landfill bioreactor was investigated under different ratios of injected leachate C/N; the denitrifying bacteria community compositions over four injection times were also studied using molecular approaches and functional gene nirS served as marker. Results showed that COD/NO3(-) -N ratio of the injected landfill leachate had a significant impact on the denitrification capacity of the bioreactor. Nitrate reduction rate increased from 1.14 mg x (kg x h)(-1) to 11.40 mg mg x (kg x h)(-1) when the injected leachate COD/NO3(-) -N ratio raised from 3.11 to 13.08. It suggested that a stable and rapid denitrification could be obtained when bioavailable COD/NO3(-) -N ratio in the injected leachate was 6.37. In the bioreactor, the main denitrifying bacteria was similar to beta-proteobacteria, and others belonged to uncultured bacteria. Thiobacillus denitrificans and Azoarcus tolulyticus known as beta-proteobacteria were the dominant species and played an important role in NO3(-) -N consumption during the leachate injection.
authors.affiliation: College of Life and Environment Science, Hangzhou Normal University, Hangzhou 310036, China. liqianfly@gmail.com
authors.forename: Qian
authors.initials: Q
authors.lastname: Li
authors.forename: Song-Wei
authors.initials: SW
authors.lastname: Wu
authors.forename: Wei-Xiang
authors.initials: WX
authors.lastname: Wu
authors.forename: Fa-Qian
authors.initials: FQ
authors.lastname: Sun
authors.forename: Jing-Jing
authors.initials: JJ
authors.lastname: Liu
authors.forename: Chuan-Yu
authors.initials: CY
authors.lastname: Cai
authors.forename: Min
authors.initials: M
authors.lastname: Chen
mesh_terms: D020627:Azoarcus / Q000378:metabolism; D019149:Bioreactors / Q000382:microbiology*; D002244:Carbon / Q000378:metabolism; D058440:Denitrification; D009566:Nitrates / Q000378:metabolism*; D009584:Nitrogen / Q000378:metabolism; D012037:Refuse Disposal / Q000379:methods*; D013855:Thiobacillus / Q000378:metabolism*; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D009566:Nitrates; D014874:Water Pollutants, Chemical; D002244:Carbon; D009584:Nitrogen