title: Performance and microbial response during the fast reactivation of Anammox system by hydrodynamic stress control.
abstract: Anaerobic ammonium oxidation (Anammox) has become a promising method for biological nitrogen removal. However, this biotechnology application is always limited due to the low growth rate and biomass yield of Anammox bacteria. This study investigated the process of fast reactivation of an Anammox consortium idled for 2 years via hydrodynamic stress control. The results showed that the Anammox system was efficiently and quickly reactivated by shortening of the hydraulic retention time (HRT) of the reactor from 12 to 6 hr within 68 days of operation. Moreover, at a 4-hr HRT with an influent total nitrogen loading rate of 1.2kg N/(m(3)·day), the reactor maintained high biological performance with an ammonium removal loading rate of 0.52kg N/(m(3)·day) and a nitrite removal rate of 0.59kg N/(m(3)·day). In the reactivated Anammox reaction, the stoichiometric coefficients of NH4(+)-N to NO2(-)-N and NH4(+)-N to NO3(-)-N were 1:1.04±0.08 and 1:0.31±0.03, respectively. The specific Anammox activity and hydrazine oxidoreductase activity, both of which represent the degree of Anammox bacteria present, increased as the hydrodynamic stress increased and were maximally (125.38±3.01mg N/(g VSS·day) and 339.42±6.83μmol/(min·g VSS), respectively) at 4-hr HRT. Microbial response analysis showed that the dominant microbial community was obviously shifted and the dominance of Anammox bacteria was enhanced during the hydrodynamic selection.
authors.affiliation: School of Environment and Civil Engineering, Jiangnan University, Wuxi 214122, China. Electronic address: yuanl2013@sina.com.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Li
authors.affiliation: School of Environment and Civil Engineering, Jiangnan University, Wuxi 214122, China. Electronic address: biogashuang@jiangnan.edu.cn.
authors.forename: Zhenxing
authors.initials: Z
authors.lastname: Huang
authors.affiliation: School of Environment and Civil Engineering, Jiangnan University, Wuxi 214122, China. Electronic address: wqruanjn@gmail.com.
authors.forename: Wenquan
authors.initials: W
authors.lastname: Ruan
authors.affiliation: School of Environment and Civil Engineering, Jiangnan University, Wuxi 214122, China.
authors.forename: Hongyan
authors.initials: H
authors.lastname: Ren
authors.affiliation: School of Environment and Civil Engineering, Jiangnan University, Wuxi 214122, China.
authors.forename: Hengfeng
authors.initials: H
authors.lastname: Miao
mesh_terms: D064751:Ammonium Compounds / Q000378:metabolism*; D000693:Anaerobiosis; D019149:Bioreactors / Q000382:microbiology*; D059013:Microbial Consortia; D009584:Nitrogen / Q000302:isolation & purification*; D010084:Oxidation-Reduction
chemical_list: D064751:Ammonium Compounds; D009584:Nitrogen
keywords: Anaerobic ammonium oxidation; Fast reactivation; Hydrazine oxidoreductase; Hydrodynamic stress