title: The effect and biological mechanism of COD/TN ratio on nitrogen removal in a novel upflow microaerobic sludge reactor treating manure-free piggery wastewater.
abstract: A novel upflow microaerobic sludge reactor (UMSR) was constructed to treat manure-free piggery wastewater with high NH4(+)-N concentration and low COD/TN ratio, and the effect and biological mechanism of COD/TN ratio on nitrogen removal were investigated at a constant hydraulic retention time of 8h and 35°C. The results showed that the UMSR could treat the wastewater with a better synchronous removal of COD, NH4(+)-N and TN. The microaerobic UMSR allowed nitrifiers, and heterotrophic and autotrophic denitrifiers to thrive in the flocs, revealing a multiple nitrogen removal mechanism in the reactor. Both the nitrifiers and denitrifiers would be restricted by an influent COD/TN ratio more than 0.82, resulting in a decrease of TN removal in the UMSR. To get a TN removal over 80% with a TN load removal above 0.86kg/(m(3)·d) in the UMSR, the influent COD/TN ratio should be less than 0.70.
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, School of Municipal and Environmental Engineering, Harbin Institute of Technology, 73 Huanghe Road, Harbin 150090, PR China. Electronic address: ljz6677@163.com.
authors.forename: Jianzheng
authors.initials: J
authors.lastname: Li
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, School of Municipal and Environmental Engineering, Harbin Institute of Technology, 73 Huanghe Road, Harbin 150090, PR China.
authors.forename: Jia
authors.initials: J
authors.lastname: Meng
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, School of Municipal and Environmental Engineering, Harbin Institute of Technology, 73 Huanghe Road, Harbin 150090, PR China.
authors.forename: Jiuling
authors.initials: J
authors.lastname: Li
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, School of Municipal and Environmental Engineering, Harbin Institute of Technology, 73 Huanghe Road, Harbin 150090, PR China.
authors.forename: Cheng
authors.initials: C
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, School of Municipal and Environmental Engineering, Harbin Institute of Technology, 73 Huanghe Road, Harbin 150090, PR China.
authors.forename: Kaiwen
authors.initials: K
authors.lastname: Deng
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, School of Municipal and Environmental Engineering, Harbin Institute of Technology, 73 Huanghe Road, Harbin 150090, PR China.
authors.forename: Kai
authors.initials: K
authors.lastname: Sun
authors.affiliation: Centre de Recherche Industrielle du Québec, 333 Franquet, Québec G1P 4C7, Canada.
authors.forename: Gerardo
authors.initials: G
authors.lastname: Buelna
mesh_terms: D000818:Animals; D052818:Autotrophic Processes; D057919:Biological Oxygen Demand Analysis; D019149:Bioreactors; D002244:Carbon / Q000032:analysis* / Q000737:chemistry; D058440:Denitrification; D008372:Manure; D009584:Nitrogen / Q000032:analysis* / Q000737:chemistry; D013552:Swine; D014865:Waste Disposal, Fluid / Q000379:methods; D062065:Wastewater / Q000737:chemistry*
chemical_list: D002244:Carbon; D008372:Manure; D009584:Nitrogen; D062065:Wastewater
keywords: Biological mechanism; COD/TN ratio; Microaerobic treatment; Nitrogen removal; Piggery wastewater