Characteristics of anammox reactor and optimal regulation of substrate ratio during start-up process
In order to efficiently start up the anaerobic ammonia oxidation(Anammox),the up-flow anaerobic sludge blanket(UASB)reactor was inoculated with anammox sludge and activated sludge with a volume ratio of 1:2,and the nitrogen loading rate(NLR)of the reactor was adjusted by gradually increasing the influent substrate concentration and optimizing regulation of substrate ratio.The denitrification performance,sludge characteristics,and microbial community structure of the reactor during the start-up process were investigated.The results show that by increasing substrate concentration three times and optimizing regulation of substrate ratio once,the NLR reached 2.16 kg N/(m3·d),and the nitrogen removal efficiency(NRE)and nitrogen removal rate(NRR)reach 87.60％and 1.89 kg N/(m3·d),respectively.The anammox reactor is successfully started up after 90 d.When the influent NH4-N and NO2--N mass concentrations are 250 mg/L and 330 mg/L[NLR was 2.38 kg N/(m3·d)],respectively,the NRE is only 73.75％;The EPS content and particle size of granular sludge are increased significantly;The specific anammox activity(SAA)decreases from 148.57 mg N/(g VSS·d)to 112.77 mg N/(g VSS·d),and the heme c decreases from 1.59μmol/g VSS to 0.60 μmol/g VSS.The excessive NO2--N in the influent inhibited the activity of AnAOB,which leads to the deterioration of the reactor performance.The substrate ratio is adjusted from 1:1.32 to 1:1.10,the NRE is increased to 87.60％,and the EPS content and particle size of granular sludge are decreased.The SAA is increased to 151.12 mg N/(g VSS·d),and the heme c is increased to 1.62 µmol/g VSS.The inhibition of AnAOB activity by excessive NO2--N mass concentration can be relieved by appropriate adjustment of the substrate ratio,and the denitrification performance of the reactor is recovered rapidly.Microbial community structure analysis shows that microbial abundance and diversity decreased during the start-up process,and the abundance of Planctomycetes increased to 43.60％significantly.When the denitrification performance of the reactor is inhibited,the dominant genus of functional bacteria is Candidatus_Brocadia(20.36％).After the substrate ratio is adjusted to mitigate the inhibition,the abundance of Candidatus_Kuenenia reaches 32.19％,replacing Candidatus Brocadia as the dominant genus.
environmental engineeringanammoxstart-upnitrogen removalgranular sludgemicrobial community
万方数据
维普
