纳米ZnO颗粒的制备及其对颗粒污泥硝化反应的影响

Effect of nano-ZnO particles pollution on nitrification of granular sludge

通过溶胶凝胶法制备纳米氧化锌颗粒。利用XRD、红外光谱和SEM图谱对制备的纳米氧化锌的物相和形貌进行表征,在实验溶液中检测纳米氧化锌的溶解,通过SEM观察ZnO对污泥形态的影响,同时也研究ZnO对污泥硝化反应的影响。结果表明,实验制备的六方纤锌矿ZnO粉末纯净,结晶性良好,而且ZnO颗粒为纳米颗粒且分散性良好。在实验溶液中,随着纳米ZnO颗粒添加量增加,SBR溶液内的Zn^(2+)含量逐渐增加,反应时间为270 min时,添加10、20和60 mg/L纳米ZnO颗粒的SBR系统中Zn2+含量分别为9.6×10^(-3)、16.3×10^(-3)、36.1×10-3mg/L。通过SEM观察到纳米ZnO颗粒添加后,污泥表面发现明显的纳米颗粒团聚物,污泥表面存在许多粉末状物质,很难找到黏膜状的胞外聚合物。ZnO颗粒添加量为0 mg/L的时候,颗粒污泥对氨氮的去除率可以达到96.4%,当ZnO颗粒添加量增至10和60 mg/L时,颗粒污泥对氨氮的去除率降为82.1%和59.6%。

In this paper,nano zinc oxide particlesare prepared by sol-gel method.The phase and morphology of nano zinc oxide prepared are characterized by XRD,FTIR spectrum and SEM.The dissolution of nano ZnO is detected in the experimental solution.The influence of ZnO on sludge morphology is observed by SEM,and the influence of ZnO on sludge nitration is also studied.The results showed that the powder of nano ZnO prepared is pure and has good crystallinity.The ZnO particles are nanoparticles with good dispersibility.In the experimental solution,with the increase of the amount of nano-ZnO particles,the content of Zn2+in SBR solution gradually increases.When the reaction time is 270 min,the content of Zn^(2+)in the SBR system with 10 mg/L,20 mg/L and 60 mg/L nano-ZnO particles is 9.6×10^(-3) mg/L,16.3×10^(-3) mg/L and 36.1×10-3 mg/L,respectively.It is observed by SEM that after the addition of nano-ZnO particles,obvious nanoparticle aggregates are found on the sludge surface,and there are many powdery substances on the sludge surface,so it is difficult to find mucos-like extracellular polymers.When the added amount of ZnO particles is 0 mg/L,the removal rate of ammonia nitrogen from granular sludge can reach 96.4%.When the added amount of ZnO particles increases to 10 mg/L and 60 mg/L,the removal rate of ammonia nitrogen from granular sludge decreases to 82.1%and 59.6%.