Performance of the dominant bacterial species and microbial community in autotrophic denitrification coupled with iron cycle in immobilized systems.
We used three stable reactors to investigate the rates of nitrate removal coupled with iron cycle and the subsequent influence of the reaction on bacterial communities. The iron-reducing bacterium Klebsiella sp. FC61 was immobilized on the reactor columns of the experimental groups B (only Klebsiella) and C (Klebsiella+magnetite). With the fluctuation of Fe2+to Fe3+(iron cycle), the average nitrate removal efficiency increased from 73.22% to 93.91% and 86.92% to 97.84% in groups B and C, respectively, as the influent nitrate concentration decreased from 40 to 10mg/L. However, the average rate of nitrate removal showed the opposite trend (from 2.08mg/L/h to 0.67mg/L/h and 2.41mg/L/h to 0.69mg/L/h in groups B and C, respectively) as the influent nitrate concentration decreased. Analysis of microbial distribution and community structures indicated that the population of Klebsiella sp. increased in groups B (from 18.21% to 41.21%) and C (from 25.43% to 46.80%) and contributed to the effective removal of nitrate in the reactors.
School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China; State Key Laboratory of Urban Water Resource and Environment, School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China. Electronic address: sjf1977518@sina.com.
Jun Feng
JF
Su
School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China.
Ce
C
Cheng
School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China.
Tinglin
T
Huang
State Key Laboratory of Urban Water Resource and Environment, School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China. Electronic address: weilihit@126.com.
Li
L
Wei
D052818:Autotrophic Processes; D019149:Bioreactors / Q000382:microbiology*; D018914:Cells, Immobilized; D058440:Denitrification; D007501:Iron / Q000737:chemistry*; D007709:Klebsiella / Q000378:metabolism*; D009566:Nitrates / Q000737:chemistry
D009566:Nitrates; D007501:Iron
Autotrophic denitrification; Immobilized systems; Iron cycle; Klebsiella sp. FC61; Microbial community