title: Effects of oxygen and carbon content on nitrogen removal capacities in landfill bioreactors and response of microbial dynamics.
abstract: In this study, landfill bioreactors were tested to treat the recalcitrant leachate-nitrogen and the impacts of relevant operational parameters on its conversion were comprehensively investigated. We found that the highly diverse microbial community in landfill bioreactors could be substantially affected by increasing biodegradable carbon and oxygen content, which led to the whole system's intrinsic nitrogen removal capacity increasing from 50 to 70 %, and meanwhile, the contribution of anammox was detected less than 20 %. The sequencing and q-PCR results showed that microbial community in bioreactor was dominated by Proteobacteria (∼35 %) and Acidobacteria (~20 %) during the whole experiment. The abundance of anammox functioning bacteria (Amx) kept at a stable level (-2.5 to -2.2 log (copies/16S rRNA)) and was not statistically correlated to the abundance of anammox bacteria. However, significant linear correlation (p < 0.05) was determined between the abundance of nirS and Proteobacteria; amoA and AOB. Redundancy analysis (RDA) suggested that although oxygen and biodegradable carbon can both impose effects on microbial community structure, only biodegradable carbon content is the determinant in the total nitrogen removal.
authors.affiliation: Key Laboratory for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Science; Joint Research Institute for New Energy and the Environment (East China Normal University and Colorado State University), East China Normal University, 500 Dong Chuan Road, Shanghai, 200241, People's Republic of China.
authors.forename: Weiqing
authors.initials: W
authors.lastname: Xu
authors.affiliation: Key Laboratory for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Science; Joint Research Institute for New Energy and the Environment (East China Normal University and Colorado State University), East China Normal University, 500 Dong Chuan Road, Shanghai, 200241, People's Republic of China.
authors.forename: Dong
authors.initials: D
authors.lastname: Wu
authors.affiliation: Key Laboratory for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Science; Joint Research Institute for New Energy and the Environment (East China Normal University and Colorado State University), East China Normal University, 500 Dong Chuan Road, Shanghai, 200241, People's Republic of China.
authors.forename: Jie
authors.initials: J
authors.lastname: Wang
authors.affiliation: Key Laboratory for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Science; Joint Research Institute for New Energy and the Environment (East China Normal University and Colorado State University), East China Normal University, 500 Dong Chuan Road, Shanghai, 200241, People's Republic of China.
authors.forename: Xinghua
authors.initials: X
authors.lastname: Huang
authors.affiliation: Key Laboratory for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Science; Joint Research Institute for New Energy and the Environment (East China Normal University and Colorado State University), East China Normal University, 500 Dong Chuan Road, Shanghai, 200241, People's Republic of China. bxie@des.ecnu.edu.cn.
authors.forename: Bing
authors.initials: B
authors.lastname: Xie
mesh_terms: D061271:Acidobacteria / Q000254:growth & development / Q000302:isolation & purification; D001673:Biodegradation, Environmental; D057919:Biological Oxygen Demand Analysis; D019149:Bioreactors / Q000382:microbiology*; D002244:Carbon / Q000737:chemistry*; D004269:DNA, Bacterial / Q000235:genetics; D005798:Genes, Bacterial; D009584:Nitrogen / Q000737:chemistry*; D010100:Oxygen / Q000737:chemistry*; D020560:Proteobacteria / Q000254:growth & development / Q000302:isolation & purification; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D064091:Waste Disposal Facilities; D062065:Wastewater / Q000382:microbiology
chemical_list: D002244:Carbon; D004269:DNA, Bacterial; D009584:Nitrogen; D010100:Oxygen; D012336:RNA, Ribosomal, 16S; D062065:Wastewater
keywords: High-throughput sequencing; Landfill leachate treatment; Microbial community structure; Nitrogen pathways