CuO NPs对好氧颗粒污泥形成的影响研究

Effect of CuO NPs on the cultivation of aerobic granular sludge in SBRs

采用4个SBR反应器,研究CuO NPs用量对好氧污泥颗粒形成及其稳定运行的影响。结果表明,当CuO NPs投加浓度0,0.5,1.0 mg/L和2.0 mg/L时,普通活性污泥可以被驯化培养为好氧颗粒污泥,颗粒污泥出现时间分别为26,24,28,27 d。0.5 mg/L的CuO NPs能刺激微生物生长,增加污泥浓度。COD和TN去除效果受CuO NPs影响较小,TP去除效果受CuO NPs影响较大。当CuO NPs投加浓度为0,0.5,1.0 mg/L和2.0 mg/L时,成熟颗粒污泥对TP的去除率分别为71.21%,70.34%,69.33%和60.84%。通过高通量测序发现,4个系统特有的OUT数目分别为1 637,1 562,1 958和1 584,分别占总样品的16.5%,15.75%,19.74%和15.97%,表明好氧污泥颗粒化进程中,CuO NPs的投加浓度对颗粒污泥微生物群落分布具有较大影响。污泥微生物种群结构分析,发现当CuO NPs投加浓度为2 mg/L时,变形菌门中包含大部分聚磷菌的β变形菌纲(β-Proteobacteria)比例下降明显,污泥颗粒化进程中,SBR4反应器除磷性能恶化的主要原因正是来自高浓度CuO NPs对β变形菌纲中微生物生长的抑制。

The effects of CuO NPs on the granulation of aerobic sludge were investigated in four SBRs fed.The results demonstrated that activated sludge can be cultivated as aerobic granular sludge and granular sludge began to appear on the 26,24,28 d and 27 d at 0,0.5,1.0,2.0 mg/L CuO NPs,respectively.0.5 mg/L CuO NPs could stimulate microbial growth and improve the sludge settling property.During the experiment,the removal efficiency of COD and TN was less affected by CuO NPs,while the removal efficiency of TP was greatly influenced by CuO NPs.As CuO NPs increased from 0 to 2 mg/L,the removal efficiencies of TP in the four reactors were 71.21%,70.34%,69.33%and 60.84%,respectively.High throughput sequencing found that the number of specific OUT of 4 systems were 1 637,1 562,1 958 and 1 584,respectively,accounting for 16.5%,15.75%,19.74%and 15.97%of the total samples,which indicating that the addition of different concentrations of CuO NPs in the process of aerobic sludge granulation has a great influence on the distribution of microbial community in granular sludge.Analysis of sludge microbial community structure illustrated that the proportion ofβ-Proteobacteria which contained most phosphorus-accumulating bacteria decreased significantly in 2.0 mg/L CuO NPs.The main reason for the deterioration of the phosphorus removal performance of SBR4 in the process of sludge granulation came from the inhibition of microbial growth inβ-Proteobacteria by high concentrations of CuO NPs.