title: In situ probing of microbial activity within anammox granular biomass with microelectrodes.
abstract: An anaerobic rotating biological contactor was fed with inorganic synthetic wastewater for anammox. Besides biofilm, granular biomass with average diameter of approximately 5 mm formed. NH4(+), NO2(-), NO3(-) and pH microelectrodes were used to probe microbial activity in situ within the granules. At a sufficient substrate concentration, the anammox reaction was observed in the upper layer of granules, and the most active zone was found to be in the surface of 200-400 μm. The in situ anammox activity increased with increasing substrate concentration, and a maximum ammonium consumption rate of 83.3 μmol cm(-3) h(-1) was obtained at an ammonium concentration of 1000 μmol L(-1). Under an ammonium-limited condition, denitrification activity was observed in the inner layer, and the most active zone was limited to 700-1000 μm. This study revealed that denitrification bacteria coexisted with anammox bacteria within inorganic anammox granules.
authors.affiliation: School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China.
authors.forename: Yongtao
authors.initials: Y
authors.lastname: Lv
authors.affiliation: School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China.
authors.forename: Kai
authors.initials: K
authors.lastname: Ju
authors.affiliation: School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China. Electronic address: wl0178@126.com.
authors.forename: Lei
authors.initials: L
authors.lastname: Wang
authors.affiliation: School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China.
authors.forename: Ting
authors.initials: T
authors.lastname: Sun
authors.affiliation: School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Miao
authors.affiliation: School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China.
authors.forename: Xudong
authors.initials: X
authors.lastname: Wang
authors.affiliation: School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China.
authors.forename: Fan
authors.initials: F
authors.lastname: Wei
authors.affiliation: College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China.
authors.forename: Siqing
authors.initials: S
authors.lastname: Xia
mesh_terms: D064751:Ammonium Compounds / Q000378:metabolism*; D000693:Anaerobiosis; D001419:Bacteria / Q000378:metabolism*; D018441:Biofilms; D018533:Biomass; D019149:Bioreactors / Q000382:microbiology*; D058440:Denitrification; D006863:Hydrogen-Ion Concentration; D008839:Microelectrodes; D058458:Nitrogen Cycle; D010084:Oxidation-Reduction; D012399:Rotation; D062065:Wastewater / Q000737:chemistry* / Q000382:microbiology*
chemical_list: D064751:Ammonium Compounds; D062065:Wastewater
keywords: Active zone; Anammox; Denitrification; In situ microbial activity; Microelectrodes