厌氧氨氧化附着膜膨胀床长期停运后的性能恢复过程

Performance recovery of anammox attached film expanded bed after long-term shutdown

为探究连续流反应器在经历长期停运后的性能恢复情况,重启一个已停止运行150 d的厌氧氨氧化附着膜膨胀床(AAFEB)反应器,恢复了其脱氮性能,且考察了恢复策略的可行性、颗粒污泥性质的变化及其菌群结构的改变情况。结果表明:通过逐渐降低水力停留时间(HRT)(由13 h至3 h)和逐步提高进水总氮(TN)浓度(由(67.58±4.02)mg·L^(-1)至(374.93±10.76)mg·L^(-1))的方式,在72 d的恢复期中,氮去除率(NRR)由0.117kg·(m^(3)·d)^(-1)提升至2.553 kg·(m^(3)·d)^(-1),略高于反应器停运前((2.316±0.125)kg·(m^(3)·d)^(-1)),说明该AAFEB系统的脱氮性能恢复成功。在恢复期的第21天和第63天,反应器中部污泥的平均粒径分别为644.70μm和741.65μm,均超过停运前中部污泥的平均粒径(602.24μm)。g_Candidatus_Kuenenia为系统中厌氧氨氧化菌(AnAOB)的优势菌种,而g_Candidatus_Brocadia对长期停运后恢复期条件的适应能力较强。这说明AAFEB系统内AnAOB具有良好的韧性,恢复策略可行,在经历长期停运后,AAFEB系统的脱氮性能可以得到恢复。

To explore the performance recovery of a continuous flow reactor after long-term shutdown,an anaerobic attached film expanded bed(AAFEB)reactor which had been shut down for 150 days was restarted to recover its nitrogen removal performance,and the feasibility of recovery strategy and the changes in granular sludge properties and the changes of microbial community structure were investigated.The results showed that by gradually reducing the hydraulic retention time(HRT)(from 13 h to 3 h)and gradually increasing the influent total nitrogen(TN)concentration(from(67.58±4.02)mg·L^(-1) to(374.93±10.76)mg·L^(-1)),the nitrogen removal rate(NRR)increased from 0.117 kg·(m^(3)·d)^(-1) to 2.553 kg·(m^(3)·d)^(-1),which was slightly higher than that before reactor shutdown((2.316±0.125)kg·(m^(3)·d)^(-1)),indicating that the nitrogen removal performance of AAFEB system recovered successfully.On the 21st day and the 63rd day of the recovery period,the average particle size of the sludge in the middle of the reactor were 644.70μm and 741.65μm,respectively,which were larger than that of the sludge before shutdown(602.24μm).g_Candidatus_Kuenenia is the dominant genus of anaerobic ammonium oxidation bacteria(AnAOB)in the system,while g_Candidatus_Brocadia adapted to the recovery conditions after long-term shutdown.This indicated that AnAOB in AAFEB system was resilient enough for the recovery with this strategy.After long-term shutdown,the nitrogen removal performance of AAFEB system can be recovered.