氧化锌纳米颗粒对SBR中活性污泥脱氮性能及硝化细菌丰度的影响

在SBR中添加氧化锌纳米颗粒（ZnO-NPs），研究ZnO-NPs对活性污泥脱氮性能及硝化细菌丰度的影响。结果表明，低浓度（1 mg·L-1）ZnO-NPs对活性污泥脱氮性能无影响，高浓度（10、50 mg·L-1）ZnO-NPs可抑制活性污泥硝化性能，且对硝化菌活性抑制作用小于亚硝化菌。ZnO-NPs浓度梯度增加至50 mg·L-1较直接投加50 mg·L-1 ZnO-NPs对污泥活性抑制作用小。高浓度ZnO-NPs改变活性污泥微生物胞外聚合物（EPS）产量和性质。SBR运行结束时，高浓度ZnO-NPs的添加导致亚硝化菌相对丰度大幅度减小，而对硝化菌相对丰度影响较小。

Effects of ZnO nanoparticles on nitrogen removal performance and nitrifying bacteria abundance of activated sludge in SBR

The effects of ZnO nanoparticle (ZnO-NPs) concentrations on nitrogen removal performance and abundance of nitrifying bacteria in activated sludge in a Sequencing Batch Reactor (SBR) were investigated. The results showed that low ZnO-NPs concentration (1 mg·L-1) had no obvious effect on the nitrogen removal performance of activated sludge, whereas the nitrification performance was inhibited at high ZnO-NPs concentrations (10 and 50 mg·L-1). The inhibition effects of ZnO-NPs on the nitrification activity were less than those on nitrosation activity. An increasing gradient of ZnO NPs concentration to 50 mg·L-1 resulted in less harm to the sludge, compared to direct addition of 50 mg·L-1 ZnO NPs. The production and properties of extracellular polymers (EPS) of bacteria could be changed by high ZnO-NPs concentrations. At the end of the SBR operation, the relative abundance of nitrosifying bacteria was decreased remarkably by addition of ZnO-NPs at high concentration, but no significant variation was observed in the relative abundance of nitrifying bacteria.