ZnO纳米颗粒对SBR活性污泥活性的影响

Impact of ZnO nanoparticles on the activity of the activated sludge in SBR

建立了模拟的SBR反应器,并研究了ZnO纳米颗粒(ZnO-NPs)对SBR活性污泥活性的影响.结果表明低浓度(10mg/L)ZnO-NPs对活性污泥活性无明显抑制作用.较高浓度下,ZnO-NPs对活性污泥沉降性能呼吸速率 EPS和SMP产量及其组成有机物降解效率等具有明显影响.20,50,100mg/L ZnO-NPs使COD去除率分别降低8.1%,19.5%和27.7%,使污泥沉降性能分别降低24.2%,35.0%和36.0%,使MLVSS/MLSS比值分别降低8.0%,14.7%和21%,使活性污泥呼吸速率抑制率达到54.0%,79.0%和80.3%;使EPS产量分别降低29.0%,49.9%和65.4%,使SMP产量分别升高48.9%,102.6%和203.0%.研究表明,较高浓度ZnO-NPs能够抑制污泥代谢,降低活性污泥生物量,显著抑制活性污泥活性.

The impact of ZnO nanoparticles （ZnO-NPs） on the activity of activated sludge in SBR was investigated. Results indicated that no significantly adverse effects were discovered of ZnO-NPs in the activity of activated sludge at low exposure concentration （10mg/L）. Adversely, significant effects were observed on the activities of the sludge such as sedimentation, yield and constituents of extracellular polymeric substances （EPS） and soluble microorganism products （SMP） as well as degradation efficiency of organics when ZnO-NPs was exposed to the activated sludge system at higher concentration （20,50,100mg/L）. Namely, COD removal decreased by 8.1%, 19.5% and 27.7%, respectively, the sedimentation efficiency of sludge decreased by 24.2%, 35.0% and 36.0%, MLVSS/MLSS ratio decreased by 8.0%, 14.7%and 21.0%, the respiratory rate was inhibited by 54.0%, 79.0%and 80.3%;the yield of EPS decreased by 29.0%, 49.9%and 65.4%and the yield of SMP increased by 48.9%, 102.6%and 203.0%. The results demonstrated that ZnO-NPs could inhibit the activity of activated sludge by suppressing the metabolism and yield of sludge.